Chọc hút tuyến giáp bằng kim nhỏ và xét nghiệm phân tử có giá trị trong chẩn đoán và điều trị

Y Học TP. Hồ Chí Minh * Tập 15 * Phụ bản Số 2 *
2011

Tổng quan

CHỌC HÚT TUYẾN GIÁP BẰNG KIM NHỎ VÀ XÉT NGHIỆM PHÂN TỬ
CĨ GIÁ TRỊ TRONG CHẨN ĐỐN VÀ ĐIỀU TRỊ
THYROID FINE NEEDLE ASPIRATION AND REFLEX MOLECULAR
TESTING OPTIONS OF POTENTIAL VALUE IN DIAGNOSIS
AND MANAGEMENT
Lewis A. Hassell, S. Terence Dunn, Elizabeth M. Gillies**

Tổng quan: Theo tiêu chuẩn của hệ thống
Bethesda, tế bào học tuyến giáp có một tác động
tích cực trong việc nghiên cứu và quản lý bệnh
nhân có nhân giáp. Tuy nhiên vẫn còn tồn tại một
số khó khăn trong chẩn đốn các trường hợp "tổn
thương dạng nang" nói chung và "tổn thương
dạng nang với tế bào khơng điển hình có ý nghĩa
khơng xác định" nói riêng.
Phương pháp: Theo y văn, cần đánh giá lại
các bất thường ở mức độ phân tử của tổn thương
tuyến giáp. Một số dấu ấn có giá trị để phân biệt
những trường hợp khơng điển hình từ các mẫu
chọc hút tế bào bằng kim nhỏ cần được đặt ra. Cụ
thể a) mẫu khơng được chẩn đốn; b) những
trường hợp tế bào khơng điển hình có ý nghĩa
khơng xác định và c) tổn thương dạng nang. Cần
kiểm tra độ nhạy của các xét nghiệm phân tử
tương ứng.
Kết quả: Đánh giá đột biến gen RAS trong các

mẫu tế bào học nang tuyến giáp khơng ghi nhận đột
biến. Kết quả này có giá trị phát hiện các tổn thương
dạng nang (trong đó có carcinơm). Những trường
hợp tế bào khơng điển hình có ý nghĩa khơng xác
định, bao gồm cả carcinơm dạng nhú có thể được
phát hiện qua một số xét nghiệm phân tử như BRAF,
RET/PTC, PAX8/PPAR và RAS. Một số dấu ấn
khác có độ nhạy cao cũng được kiểm tra.
Kết luận: Kết hợp tế bào học tuyến giáp và
các xét nghiệm phân tử góp phần làm tăng tần
suất chẩn đốn bệnh lý tuyến giáp. Tuy nhiên,
một số trường hợp tế bào khơng điển hình âm tính
với các dấu ấn phân tử có thể dẫn đến bỏ sót một
số trường hợp ác tính.

Chun Đề Giải Phẫu Bệnh

Background: The Bethesda system for standardized
reporting of thyroid cytology has had a significant
positive impact in improving clarity of communication
and management of patients evaluated for thyroid
nodules. Problematic areas still exist in the triage of
some of these samples, particularly those in the
categories of “follicular lesion with atypia of uncertain
significance” and “follicular lesion” categories.
Methods: The literature on molecular and genetic
abnormalities in thyroid lesions is reviewed. Potentially
useful markers or abnormalities for distinguishing
currently problematic categories of FNA cytology
samples have been identified for several settings,

specifically a) non-diagnostic samples; b) atypia of
uncertain significance; and c) follicular lesions. The
sensitivity of the respective molecular analyses in these
settings is examined.
Results: Evaluation for RAS mutation in samples
with negative or suboptimal follicular cytology may be
useful in detecting potentially significant follicular
lesions (carcinomas.) Cytologic samples with atypia of
uncertain significance, which may include the
possibility of papillary carcinomas may be fruitfully
evaluated using a panel of molecular tests for BRAF,
RET/PTC, PAX8/PPAR and RAS. The potential
utility of other markers to further enhance sensitivity are
presented.
Conclusion: We conclude that an era of combined
modality testing in thyroid cytology is emerging where
classical cytologic findings can be coupled with
molecular data to increase the predictive power of our
diagnostic interpretations, but that there remains a
group of atypical cytologic samples negative for known
molecular markers in which the risk of malignancy is too
high to ignore completely.

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Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

* i hc Oklahoma - USA

2

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011
GII THIU V BI CNH
Tn sut ung th tuyn giỏp ngy cng
tng mt s khu vc trờn th gii, cú l do
s gia tng phỏt hin cỏc trng hp ung th
tuyn giỏp dng vi nhỳ. Tuy nhiờn, t l t
vong do ung th ny M khụng thay i
ỏng k theo thi gian. Cỏch ỏnh giỏ v x
trớ cỏc nhõn giỏp cng cú s thay i rừ rt
trong sut ba mi nm qua. Hai tin b
ỏng k trong chn oỏn minh chng cho s
thay i ny. u tiờn l s ra i ca k
thut x hỡnh tuyn giỏp cho phộp phõn loi
chc nng tuyn giỏp bao gm nhõn núng
(gia tng bt x), nhõn "lnh" v nhõn khụng
bt x. S dng n thun mt k thut ny
cú th loi tr nhõn núng. Nhõn lnh
thng gp trong cỏc u tuyn giỏp v c
nhng thc th lnh tớnh.
Bc tin quan trng th hai trong qun
lý v theo dừi bnh nhõn trong nhng nm
cui ca thp niờn 20 l s ph bin ca

phng phỏp chc hỳt tuyn giỏp bng kim
nh (FNA). K thut ny tng i n gin,
cú th phõn loi cỏc tn thng tuyn giỏp
lnh tớnh v ỏc tớnh. Tuy nhiờn, nh ó núi
trờn, vn cũn gp nhiu khú khn trong chn
oỏn cỏc trng hp khụng in hỡnh, trung
gian gia lnh tớnh v ỏc tớnh.
V chn oỏn hỡnh nh, siờu õm kim tra
v chc hỳt t bo tuyn giỏp bng kim nh
ó dn dn thay th x hỡnh tuyn giỏp, cỏc
k thut ny tr nờn cú giỏ tr tip tc
chun húa v h thng húa thc hnh. Phc
v chn oỏn t bo hc tuyn giỏp c nht
quỏn v lý tng tip tc theo dừi hoc
iu tr nhng trng hp khụng trc tip
iu tr bng phu thut.

Chuyờn Gii Phu Bnh

Toồng quan

INTRODUCTION AND BACKGROUND
The incidence of thyroid cancer has been
observed to be increasing in some areas of the
world, presumably due to increased detection of
small papillary thyroid carcinomas. US mortality
rates due to this cancer however have not shifted
significantly over time(1). Evaluation and
management of thyroid nodules has changed
dramatically over the past thirty years. Two

significant diagnostic advances have catalyzed
this change. The first was the introduction of
radionuclide scanning technology using which
allowed a functional classification of thyroid
nodules into those considered hot (i.e. taking up
or trapping the radionuclide) and those that were
cold or failed to trap the radiotracer. This step
alone was useful in excluding many hot nodules
from the need for further evaluation(2). However,
the remaining cold nodules, while containing an
enriched proportion of neoplastic lesions, still
included many benign entities. The popularization
of thyroid fine needle aspiration (FNA) biopsy
during the last few decades of the 20th century was
the second important step forward in patient
management. This happened because a wealth of
evidence demonstrated that this relatively simple,
readily available technique could further
categorize thyroid lesions into some that were
clearly malignant and some that were clearly
benign. Again however, there remained a large
group of cases that fell in between, where the
malignant features could not be reliably
distinguished from the benign proliferations(3,4,5).
As experience accumulated with thyroid FNA,
and as ultrasound examination gradually
supplanted radionuclide scintigraphy in the
imaging evaluation of the thyroid, it became
valuable to further standardize and codify
cytopathologic practices to ensure consistent

communication and ideally, to further ensure
appropriate patient follow-up or treatment in
those categories not leading directly to surgical
treatment.

3


Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

Vin ung th quc gia (NCI) t chc hi
ngh vo thỏng Mi nm 2007 a ra h
thng phõn loi cỏc mu FNA tuyn giỏp,
vi y d liu nhm phõn tớch kt qu
v a ra quyt nh x trớ, theo dừi bnh
nhõn. p dng h thng Bethesda trong
thc hnh lõm sng cng hu ớch trong
qun lý cỏc bnh nhõn cú nhõn giỏp.
Tuy nhiờn, h thng phõn loi ny
khụng phi ti u. Nhiu trng hp cú th
tri qua phu thut "khụng cn thit".
Tng t nh vy, nhiu trng hp c
phõn loi trong nhúm nguy c thp v chn
oỏn cui cựng l tn thng ỏc tớnh. Phi
hp vi xột nghim phõn t cú th giỳp
gim bt cỏc yờu cu v phu thut khụng
cn thit, hoc gia tng s lng cỏc trng
hp cú nguy c thp hoc trung gian cho

n khi bnh c xỏc nh chc chn l
lnh tớnh hoc ỏc tớnh.

Nhng bin i di truyn-phõn t trong
ung th tuyn giỏp dng nang
Carcinụm tuyn giỏp dang nang l ung
th biu mụ tuyn giỏp ph bin th hai.
Bnh cú nhiu yu t nh hng, bao gm
thiu it, tip xỳc vi bc x ion húa, cú
kốm bnh lnh tớnh ca tuyn giỏp tn ti
t trc (nhõn n c/u tuyn, phỡnh
giỏp) v mt s hi chng gia ỡnh (bnh
Cowden, hi chng Werner, hi chng
Carney).
Bnh Cowden l mt bnh him, do ri
lon gen tri trờn NST thng gõy ra bi
t bin dũng t bo mm trong gen PTEN
nm trờn nhim sc th 10q22-23. Nhng
tn thng tuyn giỏp thng gp bnh
nhõn bnh Cowden, xp x 10-20% tn
thng tuyn giỏp tin trin thnh ung th.

4

The outcome of a National Cancer Institute
(NCI) consensus conference held in October of
2007, was a tiered classification system of thyroid
FNA samples, linked with sufficient follow-up
data to provide clinicians and patients a structure
under which to interpret the reported findings and

make management decisions(6). Application of the
Bethesda system in clinical practice has already
been reported to have a salutary impact on patient
management(7,8).
But despite these advances, there are still
several situations in which the best efforts at
evaluation yield inconclusive results. While it is
encouraging that we can identify groups of
patients with elevated risk of harboring a
malignancy in the thyroid, for a patient in a high
risk group who undergoes needless surgery for
a lesion ultimately found to be benign, the
classification system has not provided the best
outcome. Similarly for patients in low risk groups
who ultimately are found to have a malignancy,
the evaluation protocols have been suboptimal. It
is into this abyss that the molecular diagnostician
enters with the intent of providing additional
information that may reduce the requirement for
needless surgery, or increase the number of low or
intermediate risk individuals who endure
uncertainty until their disease can fully declare
itself benign or malignant.

Molecular-genetic alterations in
follicular carcinomas

thyroid

Follicular carcinomas are the second most

common type of thyroid malignancy. They
appear to be associated with several potential
etiologic or predisposing factors, including
iodine deficiency, exposure to ionizing
radiation, pre-existing benign thyroid disease
(solitary nodule/adenoma, goiter) and some
familial syndromes (Cowden disease, Werner
syndrome, Carney complex)(9).
Cowden disease is a rare autosomal
dominant disease caused by a germline
mutation in the PTEN gene located on
chromosome 10q22-23. Thyroid lesions are
common in these patients, with approximately
10-20% developing carcinomas(10).

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011
Hi chng Werner cng l mt ri lon
him gp. Bnh cú t bin gen ln trờn
NST thng, t bin dũng t bo mm trờn
gen WRN thuc NST 8p11-12, tn sut kt
hp vi carcinụm tuyn giỏp dng nang
khong 3%. Bt thng v gen c tỡm
thy trong phn ln cỏc carcinụm tuyn
giỏp dng nang, liờn quan n nhim sc
th 7, 8, 11, 17, 18 v mt s hin din v
trớ gen PAX8, PPAR hoc c hai. Chỳng cú

th c phỏt hin bng phng phỏp lai ti
ch gn hunh quang.
t bin sinh dngthng gp nht
trong carcinụm tuyn giỏp dng nang (chim
40-50% trng hp) liờn quan vi protein
truyn tớn hiu t gen NRAS, HRAS, c bit
ti cỏc axit amin 12, 13 v 61. Tht vy, cú n
30% trong tt c cỏc ung th ngi cú t
bin gen RAS. Trong u tuyn giỏp, t bin
gen NRAS thng gp nht, tip theo l gen
HRAS v KRAS. t bin gen Ras phỏ v
hot ng ca men GTP v kớch hot protein
MPAK (kớch thớch hot ng phõn bo) v
phosphatidylinositol-3 kinase (PI3K) trong
con ng hot húa tớn hiu t bo, dn n
ri lon c ch iu hũa v gen, thỳc y t
bo tuyn giỏp tng sinh v bit húa. Tuy
nhiờn, kớch hot gen Ras t bin khụng c
hiu trong carcinụm tuyn giỏp dng nang,
cú th gp trong u tuyn v tn thng khỏc
nh phỡnh giỏp tng sn, t bin gen RAS
gi vai trũ trong s tin trin ca khi u v
s nhy cm vi yu t sinh ung. t bin
gen Ras thng gp nhng u tin trin v u
khụng bit húa. t bin thng gp th hai
c tỡm thy trong carcinụm tuyn giỏp
dng nang, vi xut 30-40% v ch chim
mt t l nh trong cỏc u loi phng bo, liờn
quan n gen phi hp PAX8 v PPAR, theo
sau chuyn v t (2, 3) (q13; p25). Prụtein c

to ra t gen phi hp PAX8/PPAR, to ra
tỏc ng õm tớnh trờn chc nng bỡnh thng
ca gen PPAR, õy l gen c ch s phỏt
trin v bit húa t bo nang tuyn giỏp.

Chuyờn Gii Phu Bnh

Toồng quan

Werner syndrome is a rare autosomal
recessive disorder with a germline mutation in the
WRN gene on 8p11-12, and associated with
thyroid follicular carcinoma in about 3% of
patients(11).
Conventional
cytogenetic
abnormalities are found in a majority of follicular
carcinomas, and involve a variety of chromosomes
(7, 8, 11, 17, 18) and some of these appear to
involve either the PAX8 or PPAR loci or both.
Fusion of these two can be detected using
fluorescent in-situ hybridization (FISH) probes.
The most common somatic mutations seen in
follicular carcinomas (40-50% of cases) involve the
N-ras, H-ras and N-ras signalling proteins,
especially those located in amino acids 12, 13, and
61. Indeed, up to 30% of all human cancers have
RAS mutations. NRAS mutations are most
frequent in thyroid tumors, followed by HRAS
and KRAS. The general outcome of mutation of

these Ras genes is disruption of their intrinsic
GTPase activity and constituitive activation of the
Raf-MEK-mitogen-activated
protein
kinase
(MAPK)
and
phosphatidylinositol-3-kinase
(PI3K)/AKT cell signalling pathways, leading to
dysregulation of specific genes that promote
thyroid
proliferation
and
differentiation.
Activating Ras mutations, however, are not
specific for follicular thyroid carcinoma, and have
been observed in follicular adenomas, and lesions
classified as hyperplastic nodules, suggesting that
they play a role in tumor progression and
susceptibility to carcinogenesis(12). Ras mutations
have also been associated with increased
aggressiveness and are found more frequently in
undifferentiated tumors. The second most
common mutation found in follicular thyroid
carcinomas, identified in30-40% of cases, although
only in a small proportion of oncocytic type
tumors, involves fusion of the promoter of PAX8
with the PPARgene following t(2;3)(q13;p25)
rearrangement. The PAX8/PPARfusion protein
appears to have a dominant-negative effect on the

normal functioning of PPAR, which normally
inhibits follicular growth and promotes

5


Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011
differentiation.

V vi th, khi u cú kốm chuyn v ny
thng cú cu trỳc c, t l xõm nhp
mch mỏu cao, him khi cú kốm t bin
gen Ras, iu ny cho thy chỳng i theo
con ng bnh sinh khỏc. t bin ny ớt
khi c quan sỏt trong u tuyn do xu
hng xõm nhp mch mỏu sm v vỡ vy
thng gp la tui tr. V vi th, cu trỳc
thng gp l nang tuyn nh, dng c
hoc bố, v bao si dy, húa mụ min dch
dng tớnh vi galectin-3 v / hoc HBME1, du n min dch ny rt hu dng trong
vic phõn bit u tuyn giỏp lnh tớnh hay ỏc
tớnh.
Mt s t bin gen khỏc c mụ t
trong carcinụm tuyn giỏp dng nang, cỏc
t bin ny cú th nh hng n con
ng tớn hiu PI3K kim soỏt s sng,
phỏt trin v di c ca t bo. Con ng
tớn hiu ny úng vai trũ quan trng trong

tin trin ca u hn l c ch bnh sinh.
t bin gen PIK3CA thng gp trong 613% carcinụm tuyn giỏp dng nang v s
lng bn sao gen gia tng lờn n 25%.
t bin gen RAS v PTEN cú th hot
ng thụng qua con ng ny. 6-12%
carcinụm tuyn giỏp dng nang cú t bin
gen PTEN lm gim chc nng ca protein
PTEN, dn n kớch hot AKT v dũng
thỏc tớn hiu ca nú. Nhng thay i nờu
trờn c ỏp dng ch yu trong chn oỏn
carcinụm tuyn giỏp dng nang. Mc dự
mt s u tuyn dng phng bo cú t bin
gen RAS v cỏc t bin khỏc, tuy nhiờn
tiờu chun c th vn cha c xỏc nh.
Gn õy ghi nhn nhng khi u ny cú t
bin gen GRIM19. õy l gen c ch t bo
cht theo lp trỡnh, gi vai trũ trong bnh
sinh ca u. Cha cú vai trũ rừ rng ca t
bin DNA ti th, c tỡm thy phng
bo, trong c 2 trng hp l u v khụng
phi u.

6

Tumors with this translocation have a more
solid growth pattern and a higher rate of
vascular invasion than tumors without this
rearrangement(13). Only rarely do they also show
Ras mutations, suggesting that they follow a
different path of oncogenesis. This mutation is

rarely observed in follicular adenomas due to
their propensity for early vascular invasion and
therefore presentation at an early age. When
found, they often demonstrate a morphologic
phenotype of microfollicular, solid/trabecular
growth,
thick
fibrous
capsule
and
immunophenotype-positive
for
galectin-3
and/or HBME-1(14), markers that have been
reported to be occasionally useful in
differentiating benign and malignant thyroid
tumors.
Several other gene mutations are described in
follicular thyroid carcinomas, and several of these
influence PI3K signaling that oversees cell
survival, proliferation and migration. It appears
this pathway may be more important in tumor
progression than tumorogenesis(15). The PIK3CA
gene is mutated in 6-13% of follicular thyroid
carcinomas, and gene copy numbers are increased
in up to 25% of such tumors(16,17). Additionally,
mutations in RAS and PTEN may act via this
pathway. PTEN mutations are indentified in 6-12%
of follicular carcinomas, and act to decrease the
function of PTEN, resulting in activation of AKT

and its downstream targets(18). The changes
mentioned above apply primarily to traditional
follicular carcinomas. Although some oncocytic
follicular tumors have RAS and other mutations, a
consistent pattern has not been identified.
Recently, mutations in the GRIM19 gene have been
identified in a number of these tumors(19). This
anti-apoptotic gene could play a role in
tumorigenesis. Any role for mitochondrial DNA
mutations, which can be found in both neoplastic
and non-neoplastic oncocytic cells, has not been
firmly identified.

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011

Toồng quan

Bin i phõn t trong carcinụm tuyn
giỏp dng nhỳ

Molecular alterations in thyroid papillary
carcinomas

Carcinụm tuyn giỏp dng nhỳ l ung
th tuyn giỏp thng gp nht, c bit
cỏc nc phng Tõy. Tn sut ca bnh

cao v do nhiu yu t, bao gm phỏt hin
qua siờu õm tuyn giỏp, gia tng chn oỏn
cỏc bin th nang v nhỳ, tip xỳc vi bc
x ion húa trong mụi trng, ch n
giu it. Ngoi ra, bng chng cho thy cỏc
bnh lnh tớnh ca tuyn giỏp nh viờm
tuyn giỏp Hashimoto, u tuyn nang v
bnh Grave cú th phỏt trin thnh
carcinụm tuyn giỏp dng nhỳ.

Papillary carcinoma is the most common
thyroid malignancy, and, at least in the Western
world, is increasing in frequency. This has been
attributed to several factors, including increased
detection due to use of ultrasound in evaluation of
the thyroid, improved diagnostic recognition of
follicular and other variants of papillary
carcinoma, increased exposure to ionizing
radiation in the environment, and an apparent
increase in iodine rich diets(20). In addition to these
recognized factors, evidence suggests that benign
thyroid diseases such as Hashimotos thyroiditis,
follicular adenoma and Graves disease are present
in an increased number of patients who develop
papillary carcinoma.

Yu t di truyn ph h cng liờn quan
trong mt s trng hp. Bnh nhõn cú
bnh a polip gia ỡnh (FAP), ri lon gen
tri trờn NST thng c c trng bi

t bin gen APC gia tng nguy c phỏt
trin thnh carcinụm tuyn giỏp dng nhỳ,
c bit l bin th dng sỏng c.
Carcinụm tuyn giỏp dng nhỳ cú tớnh di
truyn, vi bt thng gen tri trờn NST
thng. Mt s liờn kt vi nhng v trớ
chromosome c bit. Bt thng v t bo
c quan sỏt mt s ớt trng hp
carcinụm tuyn giỏp dng nhỳ. Tng t
nh carcinụm tuyn giỏp dng nang, nhiu
t bin sinh dngc phỏt hin trong
carcinụm tuyn giỏp dng nhỳ, liờn quan
n con ng tớn hiu MAPK. Tuy nhiờn,
khụng ging nh carcinụm tuyn giỏp
dng nang, hn 70% carcinụm tuyn giỏp
dng nhỳ cú t bin gen BRAF hoc gen
RAS, hoc tỏi sp xp li nhim sc th liờn
quan n gen RET v gen NTRK1. t bin
gen BRAF ph bin nht trong carcinụm
tuyn giỏp dng nhỳ,chim tn sut khong
45%, kt qu l kớch thớch liờn tc MEK v
ERK, kớch thớch dũng thỏc tớn hiu trong con
ng MAPK, kim soỏt cỏc gen liờn quan
n tng sinh t bo, bit húa v cht theo lp
trỡnh. Hu ht cỏc t bin trong ung th
tuyn giỏp l t bin im ti mó cú th t

Chuyờn Gii Phu Bnh

Hereditary factors have been implicated in

some cases. Patients with familial adenomatous
polyposis (FAP), an autosomal dominant
disorder characterized by mutation of the APC
gene, experience a markedly increased risk of
developing papillary carcinoma, particularly
the cribriform-morular variant(21). A familial set
of papillary carcinomas also is observed, most
often with autosomal dominant inheritance,
some with linkage to specific chromosome
areas, but not yet to a specific gene(22,23).
Cytogenetic abnormalities are observed in a
minority of cases of papillary carcinoma(24).
Similar to follicular carcinomas, many of the
somatic mutations detected in papillary
carcinoma affect MAPK signalling; however,
unlike follicular carcinomas, more than 70% of
papillary carcinomas harbor one of the
recognized mutations in BRAF or RAS genes, or
a chromosomal rearrangement involving RET
and NTRK1 genes(25,26).BRAF mutations are the
most commonly detected abnormality in
papillary thyroid carcinoma, seen in roughly
45% of cases, and result in continuous
stimulation of MEK and ERK, downstream
effectors in the MAPK pathway, that are
responsible for control of expression of several

7

Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

600, cũn gi l BRAFV600E, mc dự BRAFK601E
ó c mụ t trong u tuyn v cỏc bin th
nang ca carcinụm tuyn giỏp dng nhỳ. U cú
t bin gen BRAF thng l carcinụm tuyn
giỏp dng nhỳ loi c in (mc dự t bin
gen BRAF cng c tỡm thy trong cỏc bin
th t bo cao, bit húa kộm hoc khụng bit
húa). Bnh thng tin trin. Mt t bin sinh
dng khỏc cng thng gp trong hu ht
carcinụm tuyn giỏp dng nhỳ, vi tn sut
khong 20-30%, liờn quan n vic tỏi sp xp
li gen RET trờn nhim sc th 10q11.2. Qua
ú, gen RET chu nh hng bi ớt nht mt
trong 15 gen khi ng. S tỏi sp xp ny,
RET / PTC, dn n kớch hot gen RET v con
ng MAPK. Ph bin nht l s tỏi sp xp
li gen RET/PTC 1 v 3. Bc x ion húa
thng i kốm vi s tỏi sp xp li gen trong
u, thng gp la tui tr.
Carcinụm tuyn giỏp dng nhỳ loi c
in thng cú gen RET/PTC1, trong khi ú,
carcinụm tuyn giỏp dng nhỳ loi c
thng cú s hin din ca gen RET/PTC3. S
tỏi sp xp gen RET/PTC cng thng gp
trong cỏc ung th loi vi nhỳ. Cỏc bin i v
gen xy ra sm v c xem nh bnh sinh

ca u. Nhng u ny thng khụng tin trin
thnh carcinụm tuyn giỏp loi thoỏi sn hoc
bit húa kộm. t bin im trờn gen NRAS,
HRAS v KRAS chim mt t l thp trong
carcinụm tuyn giỏp dng nhỳ, xut
khong 10%, chỳng thng gp trong
carcinụm tuyn giỏp dng nang.
V hỡnh thỏi, carcinụm tuyn giỏp dng
nhỳ cú t bin gen Ras, u thng cú v bao,
c im v nhõn khụng ni bt. T l di cn
hch ca nhng trng hp ny thng cao
nhng thp hn cỏc carcinụm tuyn giỏp
dng nhỳ khỏc. t bin gen thng gp th
t liờn quan vi s tỏi sp xp li gen
neurotrophic tyrosine kinase I (NTRK1), kớch
hot con ng tớn hiu MAPK, thng ch
c tỡm thy trong carcinụm tuyn giỏp

8

genes
involved
in
cell
proliferation,
differentiation and apoptosis. Most mutations
in thyroid carcinomas are due to point mutation
of codon 600, designated BRAFV600E, although
BRAFK601E has been described in adenomas and
the follicular variant of papillary thyroid cancer.

BRAF-positive tumors are usually classical
papillary thyroid carcinomas (although BRAF
mutations are also seen in the tall cell variant,
poorly differentiated thyroid cancer and
undifferentiated thyroid cancer of papillary
origin) and appear to have a more aggressive
course(27).
Another frequent (20-30%) somatic mutation
found almost exclusively in papillary carcinomas
involves chromosomal rearrangements of RET at
10q11.2, whereby RET falls under the influence of
the promoter of one of at least 15 other separate
genes.
These
rearrangements,
designated
RET/PTC, result in constituitive activation of RET
and stimulation of the MAPK pathway. The most
common of these rearrangements are RET/PTC 1
and 3(28).Ionizing radiation seems to be a frequent
co-factor in tumors with these rearrangements,
along with younger age. RET/PTC 1-associated
tumors are usually classic-type papillary
carcinomas, while those associated with RET/PTC
3 are more commonly a solid-type papillary
carcinoma(29). RET/PTC rearrangements have also
been described frequently in microcarcinomas,
suggesting that they are an early genetic event in
tumorigenesis. These tumors have been found to
be unlikely to progress to anaplastic or poorly

differentiated carcinomas. Point mutations in
NRAS, HRAS, and KRAS genes are seen in a lower
percentage of papillary carcinomas, roughly 10%,
and these are most commonly follicular variant
carcinomas(30).
Morphologic correlates of papillary carcinoma
with Ras mutations include encapsulation and less
prominent nuclear features usually associated
with papillary carcinoma. Rates of lymph node
metastasis from these tumors have been
conflictingly reported to be higher(31) and lower29

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011
dng nhỳ. Khi th th mng tyrosine kinase
kt hp vi cht kt ni l yu t phỏt trin
hng thn kinh s kớch hot gen Ras v con
ng MAPK. Ba gen TPM3, TPR v TFG
hin din ch yu trong cỏc t bo nang
tuyn giỏp, v trong carcinụm tuyn giỏp
dng nhỳ cú s tỏi sp xp li gen cựng vi
gen NTRK1 trờn NST 1q22. Gen NTRK1
khụng thng biu hin trong mụ tuyn
giỏp, nhng khi cú s tỏi sp xp li vi mt
trong ba gen trờn, vựng tyrosine kinase trong
t bo ca gen NTRK1 c biu hin trong
protein phi hp, kớch hot con ng

MAPK v c xem nh bnh sinh ca u. Tỏi
phỏt xy ra vi xut di 5%. Trong
carcinụm tuyn giỏp dng nhỳ, s tỏi sp xp
gen khụng liờn quan vi bt k c im mụ
hc c bit no.
t bin gen RAS (cng nh t bin gen
PTEN hoc PIK3CA), dn n kớch hot con
ng truyn tớn hiu PI3K/PTEN/AKT, cú
th gp trong carcinụm tuyn giỏp dng nhỳ,
him gp hn carcinụm tuyn giỏp loi thoỏi
sn v dng nang.
S biu hin v gen trong carcinụm
tuyn giỏp dng nhỳ khỏc nhau cỏc
nhúm mụ hc. Mt s yu t gúp phn vo
vic phõn loi mụ hc ca u nh cu trỳc
khỏc nhau gia cỏc bin th c in, nang
v cỏc bin th khỏc.
Nhiu gen cú tớnh tng iu hũa, c bit
l gen MET, LGALS3 (galectin-3) v KRT19
(cytokeratin 19).
MicroRNAs (miRNAs hoc miRs) l
nhng phõn t RNA khụng mó húa protein,
úng vai trũ nh tỏc nhõn iu hũa tng hp
protein trong t bo, biu hin cỏc sn phm
ca gen sinh ung v gen ố nộn u. Mt s

Chuyờn Gii Phu Bnh

Toồng quan

than with other papillary carcinomas. A fourth
molecular genetic mutation, which is found
exclusively in papillary carcinomas and results in
activation of the MAPK pathway involves
rearrangement of the neurotrophic tyrosine kinase
I (NTRK1) gene (TRK rearrangement). When this
membrane receptor tyrosine kinase binds its
ligand, nerve growth factor, it activates Ras and
the MAPK pathway. Three genes (TPM3, TPR, and
TFG), all highly expressed in thyroid follicular
cells, undergo rearrangement with NTRK1, located
at 1q22, in papillary thyroid cancer(32). NTRK1 is
not normally expressed in thyroid tissues, but
when rearranged with one of these three genes,
the intracellular tyrosine kinase domain of NTRK1
becomes expressed in the fusion protein, thus
activating the MAPK pathway and driving
tumorigenesis(33). Occurring in less than 5% of
papillary
carcinomas
overall,
these
rearrangements are not associated with any
particular histologic features. Prevalence of the
finding does vary considerably between locations
and populations.
RAS mutations (as well as PTEN or PIK3CA
mutations), resulting in activation of the
PI3K/PTEN/AKT signalling pathway, are also
occasionally observed in papillary carcinoma, but

are uncommon when compared with their
frequencies
in
anaplastic
and follicular
carcinomas.
Gene expression profiles of papillary thyroid
carcinomas have been done for many of the
histologic subtypes of this cancer. These have
contributed further rationale for the histologic
categorization of these tumors, as different
patterns have been seen between classic, follicular
and other variants(34).
Additionally, several genes are observed to
be up-regulated, specifically MET, LGALS3
(35)
(galectin-3) and KRT19 (cytokeratin 19) .
MicroRNAs (miRNAs or miRs) are nonprotein coding RNA molecules that act as
molecular regulators (primarily inhibitors) of
protein synthesis within the cell, including the

9


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Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011
expression of various oncogene and tumor
suppressor gene products. Several specific

miRNAs c hiu c tỡm thy trong
carcinụm tuyn giỏp dng nhỳ, bao gm tng
iu hũa ca miR-221, miR-222, miR-224,
miR-155, miR-187, miR-181b v miR-146b.
Carcinụm tuyn giỏp dng nang cng cú biu
hin tng iu hũa ca miR-221, miR-222,
miR-155, miR-187, miR-181b, v miR-224.
Chỳng úng vai trũ quan trng trong bnh
sinh ca ung th biu mụ tuyn giỏp v v
lõu di cú th hu ớch trong chn oỏn.

Cỏc bin i phõn t trong cỏc u ỏc
tớnh khỏc ca tuyn giỏp
Carcinụm tuyn giỏp bit húa kộm hay
cũn gi dng o l u khụng thng gp,
im c trng nht l t bo nang tuyn
mt mt phn c im ca nang. C ch
bnh sinh liờn quan n ba con ng tim
nng, mt l trc tip t biu mụ nang
tuyn giỏp, hai l t carcinụm tuyn giỏp
dng nhỳ bit húa rừ v ba l t carcinụm
tuyn giỏp dng nang bit húa rừ.
Phỏt hin bin i mc phõn t trong
cỏc u ny bao gm u xut ngun t t bo
nang tuyn bit húa rừ (t bin BRAF v
RAS) v khi u ca mt carcinụm bit
húa kộm (TP53 v catenin (CTNNB1)).
TP53 hin din trong khong mt phn ba
ung th bit húa kộm, v thm chớ xut
thng gp hn trong carcinụm loi thoỏi

sn (khụng bit húa), úng vai trũ trong
tin trin ca u. V húa mụ min dch, biu
hin p53 trong cỏc u bit húa kộm thng
tng quan vi s hin din ca t bin
gen TP53 v c nhỡn thy trong 40-50%
cỏc khi u nh vy.
Carcinụm tuyn giỏp loi thoỏi sn l u
cú ỏc cao v t bo khụng bit húa. Xut
di 2% cỏc u ỏc tớnh ca tuyn giỏp,
mc dự t l ny thay i tựy theo a lý v
thng xy ra ngi ln tui. Bnh
thng gp nhng ngi cú tin s bnh
lý tuyn giỏp lnh tớnh hoc ỏc tớnh, tin s

10

miRNAs signatures have been consistenly found
in papillary thyroid carcinoma, including upregulation of miR-221, miR-222, miR-224, miR155, miR-187, miR-181b, and miR-146b.
Follicular thyroid cancers also demonstrate upregulation of miR-221, miR-222, miR-155, miR187, miR-181b, and miR-224(36). These may play a
role in the genesis of thyroid carcinomas and in
the longterm may prove of diagnostic value(37).

Molecular alterations
malignancies

in

other

thyroid

Poorly differentiated (so-called insular)
carcinoma is an uncommon tumor, best
characterized as a thyroid tumor of follicular cells
with partial loss of follicular characteristics.
Heuristically, it may be thought of as arising along
three potential pathways, one directly from
thyroid follicular epithelium, another from welldifferentiated papillary carcinoma, and a third
from well-differentiated follicular carcinoma(38).
Molecular alterations observed in these tumors
include those observed in well-differentiated
follicular cell-derived tumors (e.g., BRAF and
RAS) that probably represent initial inciting
molecular insults and those viewed as being more
specific to poorly differentiated carcinomas (e.g.,
TP53 and catenin (CTNNB1)) that probably
represent subsequent events leading to tumor
progression. The former (TP53) is present in about
one third of poorly differentiated carcinomas, and
is
even
more
frequent
in
anaplastic
(undifferentiated) carcinomas, suggesting a role in
tumor progression. Demonstration of p53 by
immunohistochemistry in poorly differentiated
tumors frequently correlates with the presence of
TP53 mutation, and is seen in 40-50% of such

tumors(39).
Anaplastic carcinoma is a highly aggressive
malignancy of the thyroid that has lost most
evidence of follicular cell origin. It accounts for
less than 2% of thyroid malignancies, although
rates vary geographically, and characteristically
occurs in older adults. It is more frequent in

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011
thiu it hoc tip xỳc vi phúng x.
mc phõn t cho thy carcinụm
tuyn giỏp loi thoỏi sn tng t carcinụm
tuyn giỏp bit húa kộm, liờn quan vi t
bin gen TP53, xut 50-80% v t bin
catenin trong 65% trng hp. t bin
gen PIK3CA v PTEN cng gp trong
carcinụm tuyn giỏp loi thoỏi sn vi tn
sut thp, nhng trỏi vi cỏc khi u bit húa
tt, nhng t bin ny thng hin din
cựng vi t bin gen BRAF v RAS. iu
ny cho thy sinh hc phõn t úng vai trũ
quan trng trong tin trin ca ung th.
Carcinụm tuyn giỏp dng ty cú
ngun gc t t bo C ca tuyn giỏp,
chim 3-12% cỏc ung th biu mụ tuyn
giỏp. Phn ln bnh mang tớnh l t, nhng

15-30% l do di truyn gen tri trờn NST
thng. Cỏc trng hp di truyn c
phõn thnh ba loi: bnh a u tuyn ni
tit loi 2A (MEN2A), kt hp vi u sc bo
thng thn v tng sn tuyn cn giỏp;
MEN2B thng kt hp u sc bo thng
thn, u si thn kinh niờm mc, bnh
hch thn kinh ng tiờu húa; v
Carcinụm tuyn giỏp dng ty cú tớnh cht
gia ỡnh (FMTC), õy l th khụng liờn kt
vi cỏc u khỏc. Tt c nhng u ny cú kốm
t bin im lm tng chc nng dũng t
bo mm ca gen RET trờn NST 10q11.2
dn n kớch hot MAPK v nhng ng
tớn hiu khỏc kim soỏt s tng sinh, tn ti
v bit húa t bo. (Ngc li, nhng
trng hp cú t bin im v khụng lm
tng chc nng dũng t bo mm thng
kốm bnh Hirchsprung).
Bỡnh thng, gen RET hin din trờn cỏc
t bo C ca tuyn giỏp, ty thng thn,
hch giao cm v mt vi v trớ khỏc. Bnh cú
th cú cỏc t bin nhiu im, c phõn
loi thnh ba nhúm tng ng vi cỏc
tui khi phỏt v tin trin ca bnh. a s
cỏc trng hp MEN2A v FMTC thng kt
hp vi t bin vựng ngoi bo ca gen

Chuyờn Gii Phu Bnh

Toồng quan

individuals with a history of thyroid disease,
either benign or malignant, and those with a
history of iodine deficiency or radiation
exposure(40).
The molecular alterations observed in
anaplastic carcinoma are similar to those in poorly
differentiated carcinoma, but occur at increased
frequency; TP53 mutations, for example, are seen
i
in 50-80% of cases(37,41) and catenin mutations in
up to 65% of cases(42). PIK3CA and PTEN gene
mutations are also observed in a minority of
anaplastic carcinomas, but in contrast to the
situation with well-differentiated tumors where
these mutations rarely coexist with others, these
mutations are frequently present concurrent with
mutations of BRAF and RAS. This suggests that
these are also late molecular events in tumor
progression.
Medullary carcinomas are derived from the Ccells of the thyroid, and account for 3-12% of
thyroid carcinomas. The majority of tumors are
sporadic, but 15-30% are hereditary and
demonstrate an autosomal dominant pattern of
inheritance. Hereditary cases are classified into
three categories: multiple endocrine neoplasia
type
2A
(MEN2A),

associated
with
pheochromocytoma and parathyroid hyperplasia;
MEN2B associated with pheochromocytoma,
mucosal
neuromas,
gastrointestinal
ganglioneuromatosis along with marfanoid
habitus; and familial medullary thyroid carcinoma
(FMTC), which is not associated with other
tumors. All of these tumors are associated with
germline gain-of-function point mutations of the
RET gene that lead to activation of MAPK and
other signalling pathways governing cell
proliferation, survival, and differentiation, located
on 10q11.2(43,44,45). (By contrast, loss-of-function
point mutations are associated with Hirchsprungs
disease).
RET is normally expressed on thyroid C cells,
adrenal medulla, sympathetic ganglia and some
other sites(46). Multiple point mutations have been
described, which have been generally ascribed to

11


Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

RET, to iu kin nh trựng húa t ú hot
húa vựng kinase trong t bo. MEN2B liờn
quan vi t bin gen RET c quan sỏt
trong vựng ni bo, lm thay i tyrosine
kinase trong t bo. i vi ung th tuyn
giỏp, s biu hin kiu hỡnh ca nhng t
bin ny gn 100%, ct tuyn giỏp d phũng
l cn thit cho nhng bnh nhõn cú t bin
gen RET; thi im phu thut thng ph
thuc vo nguy c ca tng bnh nhõn. Gii
trỡnh t DNA hoc cỏc phng phỏp khỏc
vi mc tiờu nhm vo t bin c hiu ca
gen RET phỏt hin t bin ny cỏc
thnh viờn trong gia ỡnh, nhng ngi d b
nh hng hoc d b carcinụm tuyn giỏp
dng ty di truyn. Nhng trng hp ny
c thay th mt lng ln calcitonin.
Cỏc loi u hn hp trong tuyn giỏp cng
c mụ t, nh carcinụm tuyn giỏp dng
ty phi hp dng nhỳ, hay carcinụm tuyn
giỏp dng ty phi hp dng nang. Tn sut
bnh thng thp, mc dự vy, chỳng vn
c phõn loi thnh cỏc th riờng bit theo
WHO. Bin i v gen khụng c bỏo cỏo
rng rói trong cỏc loi u ny.

Phng phỏp phỏt hin cỏc bin i
mc phõn t trong carcinụm tuyn giỏp
Nhỡn chung, la chn cỏc phng phỏp
phỏt hin bin i v gen trong ung th

tuyn giỏp tựy thuc vo tng mu mụ.
Phng phỏp PCR thng c s dng
v cho kt qu nhanh chúng, ỏng tin cy.
ỏnh giỏ t bin im n c trong
bnh tuyn giỏp nh BRAF V600 v K601;
RAS G12 v G13 bng cỏch ỏp dng cỏc k
thut nh PCR c hiu cho allele, PCRRFLP, PCR vi phõn tớch ng cong da
vo nhit núng chy, PCR-lai (bao gm
microarrays), phng phỏp gii trỡnh t
ca Sanger v cỏc phng phỏp khỏc. S
dng PCR da vo thi gian thc (real
time PCR) cú th phỏt hin cỏc thay i
mc phõn t, trong khi nhng xột nghim
khỏc cú giỏ tr nh tớnh (dng/õm) u th

12

one of three groups that correlate with age-ofonset and aggressiveness of disease. The majority
of MEN2A and FMTC cases are associated with
mutations in the extracellular domains of RET and
appear to facilitate constitutive dimerization and
hence activation of the intracellular kinase
domain. MEN2B-related RET mutations have only
been observed in the intracellular domain, which
alter the tyrosine kinase conformation within the
cell(47). Since penetrance of these mutations for
thyroid cancer is nearly 100%, prophylactic
thyroidectomy is the standard intervention for
patients that carry a RET mutation; timing for this
surgery often depends on individual risk

assignment. Full-gene DNA sequencing or other
methods targeting specific mutations of RET have
been used to detect family members affected by or
vulnerable to hereditary medullary carcinoma and
has largely replaced calcitonin monitoring.
Mixed tumor types are also described in the
thyroid, such as mixed medullary and papillary
carcinoma, or mixed medullary and follicular
carcinoma. The numbers of such cases are limited,
although sufficient to be recognized as a distinct
WHO category(48). Specific molecular genetic
alterations have not been widely ascribed to
tumors in these categories.

Testing platforms and methods for detection
of molecular alterations of interest in thyroid
carcinomas
Generally,
the
choice
of
testing
platforms/techniques for clinical detection of
genetic alterations in thyroid cancer specimens
will be determined by the sample type available
for analysis and the type(s) of mutation to be
analyzed. PCR-based methods are commonly
employed and provide rapid, reliable and
sensitive detection for the spectrum of clinical
sample types available. Qualitative assessment of

single point mutations in thyroid disease, such as
BRAF V600 and K601 and RAS G12 and G13, can
be easily achieved using allele-specific PCR, PCRRFLP, PCR-melting curve analysis, PCRhybridization (including microarrays), Sanger
sequencing and pyrosequencing, and other

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011
hn nh lng. Hin nay, phng phỏp
nh lng phõn t phỏt hin cỏc du
n ca bnh ung th tuyn giỏp rt hn
ch, tuy nhiờn, nhng k thut ny cú th
hu ớch trong tng lai chn oỏn ung
th tuyn giỏp v theo dừi bnh nhõn sau
iu tr.
Cỏc t bin im, mt v/hoc chốn
thờm nucleotide gen RET v cỏc gen khỏc
c trng cho quỏ trỡnh bnh cú th xy ra
ti nhiu v trớ, chỳng c sng lc bng
cỏch ỏp dng phng phỏp PCR v gii
trỡnh t hoc bng cỏch s dng PCR a
mi. Phng phỏp PCR phiờn mó ngc
(RT-PCR) hoc lai ti ch gn hunh quang
cú th giỳp phỏt hin tỏi sp xp nhim sc
th, nh RET/PTC v PAX8/PPAR.
im góy liờn quan vi tỏi sp xp
nhim sc th thng xy ra trờn mt
khong cỏch ỏng k v gen, do ú, u tiờn

la chn k thut PCR da trờn khuych
i RNA, vi phng phỏp ny, trỡnh t
trờn chui DNA c gii hn. Phi thn
trng phi hp vi cỏc nhõn viờn phu
thut v gii phu bnh m bo vic
ly mu, x lý mu sinh thit kim, mu
ụng lnh phự hp cho phõn tớch RT-PCR.
Thụng thng, cỏc mụ tuyn giỏp c x
lý bng cỏch c nh trong formalin v vựi
trong paraffin (FFPE), khụng phự hp cho
RT-PCR.
Tuy nhiờn, nhng mu mụ nh vy ỏp
dng FISH cú th cú hiu qu phỏt hin
tỏi sp xp nhim sc th. Trong ung th
tuyn giỏp, mt s xột nghim chn oỏn
cha c FDA cụng nhn, v kt qu cú
th dng tớnh gi, do ú cn nh chun
cỏc phũng thớ nghim m bo nhy,
c hiu v lp li ca thớ nghim.
cú th phỏt hin cỏc t bo mang t
bin vi s lng nh, cỏc xột nghim phi
cú nhy cao, nh vy t l dng tớnh
gi cng s gia tng. Vic lp li thớ
nghim l cn thit m bo kt qu

Chuyờn Gii Phu Bnh

Toồng quan

methods(49). While real-time PCR can be used for

detection of such molecular lesions, such assays
are generally designed to generate a qualitative
(positive/negative) result rather than a quantitative
result.
Currently,
quantitative
molecular
approaches to the detection of markers of thyroid
cancer are extremely limited; however, such
techniques may realize greater utility in the future
for diagnosis of thyroid cancer and for monitoring
of patients following treatment(50,51).
In RET and other genes, point mutations,
deletions and/or insertions that characterize the
disease process, can occur at multiple locations;
these may be screened for by using multiple PCRconformational analyses followed by sequencing
or by using a conventional multiplexed-PCR
approach.
Detection
of
chromosomal
rearrangements,
such
as
RET/PTC
and
PAX8/PPAR, rely on reverse-transcriptase PCR
(RT-PCR) or fluorescence in-situ hybridization
(FISH).
Since the breakpoints involved in such

chromosomal rearrangements often occur over
considerable genetic distances, the analyte of
choice for PCR-based analysis is RNA, which
lacks the extensive intonic sequences present in
genomic
DNA.
This
demands
careful
coordination with surgical and pathology staff
to assure optimal collection and processing of
fresh or snap-frozen FNAs or biopsies that will
be suitable for RT-PCR analysis. More often,
thyroid tissues are processed by routine
formalin-fixation and paraffin embedding
(FFPE), which negates the possibility of RTPCR.
However, interphase FISH can be effectively
used to detect chromosomal rearrangements in
these FFPE thyroid tissues. Given the lack of
FDA-approved in vitro diagnostic tests for
thyroid cancer and the potential change that a
positive test result triggers in the clinical
management of patients, a rigorous validation
process must be undertaken during all
laboratory test development to assure highly
specific, sensitive and reproducible results.

13

Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

hng nh. i vi FISH, cỏc mụ c x
lý theo phng phỏp FFPE thng cho kt
qu vi cỏc tớn hiu mi khụng rừ rng v
cỏc tớn hiu ny cú th thay i nhng lỏt
ct dy, do ú, cỏc xột nghim sinh hc
phõn t phi c thc hin cn thn.

ng dng cỏc xột nghim chn oỏn
phõn t
Cỏc xột nghim phõn t thng t tin
v phc tp bờn cnh nhng nhng ỏnh
giỏ tng i n gin v lõm sng v gii
phu bnh, tuy vy, chỳng cú th giỳp
trỏnh c cỏc phu thut khụng cn thit.
Vic thc hin xột nghim sinh hc phõn t
cũn tựy thuc vo giỏ c ca xột nghim,
cõn nhc cỏc khon chi phớ iu tr cú liờn
quan, tuy nhiờn, trong nhiu trng hp,
xột nghim phõn t l cn thit v khụng
th b qua.
Do ú, vic qun lý bnh nhõn cn
quan tõm ỏnh giỏ chi phớ-li ớch t c
cho bnh nhõn v nguy c ỏc tớnh ca
bnh.

í ngha ca xột nghim sinh hc phõn

t i vi cỏc mu FNA tuyn giỏp?
Xột nghim sinh hc phõn t no nờn
c ỏp dng ?
Nguy c ỏc tớnh trờn cỏc mu t bo hc
õm tớnh thng di 3%, do ú ớt cú ng
lc thc hin cỏc xột nghim phõn t
trờn nhng bnh nhõn ny vo thi im
ú. Tng t, trờn cỏc mu dng tớnh hay
c phõn loi ỏc tớnh, vic thc hin xột
nghim phõn t vi mc ớch chn oỏn l
khụng cn thit vỡ xut ỏc tớnh trờn t
bo hc c khng nh chc chn trong
97-98% trng hp, mc dự vy, cỏc xột
nghim phõn t cú th c xem xột vỡ
nhng lý do khỏc c cp di õy.
Xột nghim tỡm t bin gen BRAF
trong cỏc mu t bo hc khụng in hỡnh
hoc khụng xỏc nh cú th hu ớch trong
chn oỏn carcinụm tuyn giỏp dng nhỳ.

14

While there is a desire to be able to detect low
numbers of cells that carry a mutation, this must
be tempered with the realization that increased
false-positivity will accompany ultrasensitive
detection methods. Reproducibility testing is
essential in establishing clinically relevant cutoff values for all these tests. For interphase
FISH, sectioning of FFPE tissues often results in
nuclei with less than the full complement of

probe signals and signal patterns also may vary
with section thickness, therefore, appropriate
cut-off values need to be carefully established
during the validation of these assays.

Application of molecular diagnostic testing
to clinical and cytologic scenarios
Application of molecular testing introduces
potentially costly and complex additional
testing to what has been a relatively simple
cascade of clinical and pathologic evaluations,
albeit one with a high proportion of potentially
avoidable surgical outcomes. Thus, the utility of
any reflex molecular algorithm is, in part,
dependent on both the cost of this added
laboratory testing weighed against the savings
of surgical and other over-treatment-related
costs, discounted by any adverse outcomes due
to under-treatment. Because of the need to
evaluate panels of genetic markers in many
cases, this cost is not trivial.
Hence, several questions in management
need to be addressed as this cost-benefit
evaluation will differ according to the numbers
of patients in a given cytologic category and the
relative risk of malignancy in that category.

Does molecular testing of FNA samples
make sense for all, some or none of the
categories of thyroid cytologic samples? And

what molecular test(s) should be applied to
these?
Since the risk of malignancy in cytologically
negative samples is less than 3%, there is little
impetus to perform molecular testing on these
patients at this time. Similarly, in samples
categorized as positive for malignancy, further
molecular testing with diagnostic intent is

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011

Toồng quan

Tng t nh vy, vic tỏi sp xp li gen
RET/PTC cng c hiu i vi carcinụm
tuyn giỏp dng nhỳ. t bin gen RAS
khụng c hiu i vi carcinụm tuyn
giỏp dng nhỳ hoc nang v cng khụng
c hiu cho ung th biu mụ vỡ chỳng
cng c tỡm thy trong mt s tỡnh trng
lnh tớnh. Nhng s hin din ca t bin
ny kt hp vi cỏc c im lõm sng v
t bo hc cú th hu ớch trong iu tr. Vớ
d, t bin gen RAS c tỡm thy trong
tn thng dng nang v cú th gp
trong carcinụm tuyn giỏp dng nhỳ bin

th nang hoc u tuyn. Nhng u tuyn cú
kốm t bin ny cú th tin trin thnh
carcinụm tuyn giỏp dng nang, do ú
phu thut ct b u tuyn l cn thit.

superfluous, though it may be considered for
other reasons mentioned below, as malignancy
is confirmed in this setting in 97-98% of cases.

Ngoi ra, s hin din ca u tuyn cú
kốm t bin gen BRAF cú ý ngha tiờn lng
v d bỏo cỏc bin chng sau iu tr. Bnh
cú kốm t bin ny thng tin trin v
khụng ỏp ng iu tr bng iod phúng x
do suy gim kh nng hp th iod. Hn na,
liu phỏp mi nhm mc tiờu n gen BRAF
ó c s dng thnh cụng trong mt s
ung th biu mụ tuyn giỏp.

cytologically classified follicular lesion could

mt s nghiờn cu v carcinụm
tuyn giỏp dng nhỳ hoc nang, giỏ tr tiờn
oỏn dng ca xột nghim phỏt hin t
bin gen BRAF, RET/PTC v PAX8/PPAR
l 100%. Giỏ tr tiờn oỏn dng trong t
bin gen RAS vo khong 87,5%. ỏnh giỏ
kt qu dng tớnh trờn t bo hc l mt
thỏch thc, c bit nhng trng hp
carcinụm tuyn giỏp dng nhỳ bin th

nang hoc carcinụm tuyn giỏp dng nang.
Do ú, mt b cỏc xột nghim phõn t bao
gm
BRAF,
RET/PTC,
RAS
v
PAX8/PPAR c t ra ỏnh giỏ
nhng trng hp t bo hc cho kt qu
ỏc tớnh khụng rừ rng. Cỏc d liu (xem
bng 1) cú xu hng h tr cho nhng
trng hp c chn oỏn l "tn thng
dng nang cú ý ngha khụng xỏc nh"

Chuyờn Gii Phu Bnh

Analysis for BRAF mutation in atypical or
indeterminate cytology samples, if positive, can be
virtually diagnostic of papillary carcinoma(52,53).
Likewise, clonal rearrangement of RET/PTC is also
reasonably specific for papillary carcinoma. RAS
mutations are not specific for papillary or
follicular carcinoma, nor indeed for carcinoma, as
they are also found in a number of benign
conditions. But the presence of this alteration in
association with other clinical or cytological
features may be useful in directing further
therapy. For example, RAS mutation found in a
represent

a

follicular

variant

of

papillary

carcinoma, or a follicular adenoma. But since this
mutation may predispose a patient to progression
of adenoma to follicular carcinoma, surgical
removal of such adenomas may be appropriate.
In addition, the presence of BRAF in thyroid
tumors
has
prognostic
and therapeutic
implications; this mutation is associated with
increased aggressiveness and lack of response of
recurrences to radioiodine due to impaired iodine
trapping mechanisms(54). Moreover, novel targeted
therapies to BRAF have been used to some success
in advanced thyroid carcinomas(55).
In some studies, the positive predictive value
of BRAF, RET/PTC and PAX8/PPARhas been
found to be 100% for papillary or follicular
carcinoma. RAS mutations also have a high
positive predictive value at 87.5%, and carry the

additional value of being positive in cytologic
situations that are more challenging, i.e. follicular
variants of papillary carcinoma and follicular
carcinoma(56). Thus a panel of molecular tests that
includes
BRAF,
RET/PTC,
RAS
and
PAX8/PPARhas been advocated for evaluation of

15


Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

(FLUS).
Tuy nhiờn, t l ỏc tớnh trong cỏc
trng hp "tn thng dng nang" v
"nghi ng ỏc tớnh" cũn cao, vic iu tr
nhng trng hp cú du n phõn t õm
tớnh thng khụng hiu qu, dự ỏp dng
cỏc loi phu thut khỏc nhau (ct thựy
giỏp hoc ct tuyn giỏp ton phn). Xột
nghim phõn t hu ớch cho nhng trng
hp cú xột nghim phõn t dng tớnh,
giỳp gim bt s lng cỏc bnh nhõn
c yờu cu phu thut hai ln.

S dng n thun t bo hc khỏ nhy
phỏt hin u xut ngun t t bo nang
tuyn. c hiu trong cỏc phõn loi khỏ
cao v khụng cn thờm xột nghim no
khỏc, tc l giỏ tr tiờn oỏn õm cao. B xột
nghim phõn t nh ó nờu trờn cú
c hiu cao i vi cỏc tn thng ỏc
tớnh, nhng khụng cú giỏ tr tiờn oỏn õm
cao cho cỏc trng hp t bo hc cú ý
ngha khụng xỏc nh.

Bng 1

Still significant numbers of malignancies
remain within the follicular lesion and
suspicious for malignancy groups, which means
that the clinical management of molecular markernegative patients is not significantly impacted,
although the type of surgery offered might differ
(lobectomy vs. total thyroidectomy). This could
reduce the number of patients in the molecularpositive group who would require two
procedures for proper management of their
cancer. These data illustrate (again) the importance
of sensitivity along with specificity in any testing
algorithm.
Cytology alone is quite sensitive to detecting
follicular-cell derived neoplasms. It is quite
specific in classifying those cases not needing
further evaluation, i.e. a high negative predictive
value. A molecular panel as noted above has a
very high specificity for malignant lesions, but

does not have a particularly good negative
predictive value, when applied to the group of
cytologically indeterminate cases.
Table 1

Phõn loi t
bo hc

% ỏc tớnh

% ỏc tớnh
nu du n
phõn t
dng tớnh

Lu ý

Khụng xp loi
m tớnh
FLUS

0
2-10
5-10

100
100

Tn thng
dng nang

20-30

100

Nghi ng ỏc
tớnh
c tớnh

50-70

100

0,9% nu (-)
Khụng cú ung
th trong
nhúm khụng
t bin
(n=21)
21% ung th
trong nhúm
khụng t
bin (n=23)
50% (n=7)

98

100

Trớch t d liu ca Nikiforov et al.(60)

16

cytologic samples with indefinite findings for
malignancy as a means of more reliably
categorizing these patients. The data (see Table 1)
tend to support this application especially for
those specimens categorized as follicular lesion
of uncertain significance (FLUS).

Cytologic
Category

Percentage Percentage
Notes
with
with
malignancy malignancy
cytolog
if positive
only
molecular
marker
Unsatisfactory
0
(59)
Negative
2-10
100
0.9% if negative

FLUS
5-10
100
No cancers in
mutation negative
group (n=21)
Follicular Lesion
20-30
100
21% cancers in
mutation negative
group (n=23)
Suspicious for
50-75
100
50% (n=7)
malignancy
Positive for
98
100
malignancy

Adapted from data from Nikiforov et al.(60)

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011
Xem xột ỏnh giỏ thờm miRNA vo b

du n phõn t tỡm t bin c mụ t
trờn cú th giỳp nõng cao giỏ tr tiờn oỏn
õm. Mt phng phỏp tip cn khỏc, cng
hng vo cỏc mu t bo hc khụng xỏc
nh, da trờn ỏnh giỏ phõn tớch mRNA.
Ngoi ra, trong carcinụm tuyn giỏp dng
nhỳ, ỏnh giỏ du n sinh hc trong huyt
thanh (bao gm c nhng du n phõn t
ó núi trờn) cng cho thy nhiu ha
hn.
Kt qu t bo hc dng tớnh bao gm
carcinụm tuyn giỏp dng nhỳ v dng
ty, cựng vi carcinụm tuyn giỏp loi bit
húa kộm v thoỏi sn. Núi chung, ỏp dng
xột nghim phõn t trong chn oỏn hoc
tiờn lng hai phõn loi sau cú th khụng
hiu qu. Nu chn oỏn carcinụm tuyn
giỏp da trờn t bo hc, nờn tip tc ỏnh
giỏ phỏt hin t bin gen RET. iu ny
cú th hu ớch nu cỏc thnh viờn khỏc
trong gia ỡnh c sng lc cú nhng bt
thng v dũng t bo mm tim nng.
Nghiờn cu tin cu ỏnh giỏ t bin gen
PTEN hoc NTRK1 khụng ỏp dng cho cỏc
mu t bo hc. Tuy nhiờn, vi t l tng
i thp ca cỏc t bin, k vng vo cỏc
xột nghim ny khụng cao.
p dng cỏc xột nghim phõn t vo
gii phu bnh cú mt s giỏ tr trong thit
lp chn oỏn tn thng dng nang

khụng in hỡnh ca tuyn giỏp vi nhng
c im khu trỳ ca carcinụm tuyn giỏp
dng nhỳ, khi m cỏc phng phỏp khỏc
(húa mụ min dch, nhum Hematoxylin
Eosin thng quy) thng khụng hiu qu.
t bin gen RAS, RET/PTC hoc BRAF
cú th h tr chn oỏn ung th biu mụ v
a ra hng iu tr phự hp. Cỏc tn
thng trong v bao nh vy hin th cựng
mt kiu t bin, mc dự nhng thay i
v t bo hc cú th hin din khu trỳ. S

Chuyờn Gii Phu Bnh

Toồng quan

Consideration is being given also to adding
miRNA evaluation to the panel of mutation
markers described above, in the hopes of further
improving the negative predictive value to a
clinically usable level. An alternative approach,
also directed at indeterminate cytologic
samples, based on evaluation of mRNA
analysis, has been developed and marketed by a
for-profit venture, and validated by a number of
participating academic and private institutions
in the US(57,58). Also, serum biomarker
approaches to the evaluation of thyroid
carcinoma (including those based on the
molecular markers discussed above) show

promise(59).
The positive for malignancy cytologic category
will include both differentiated thyroid
carcinomas of papillary type and medullary type,
together with poorly differentiated and anaplastic
tumor types. Generally the latter two categories
may not benefit from further molecular testing in
terms of diagnosis or prognosis. If a medullary
carcinoma is recognized cytologically as an index
case, further evaluation of the patient, or the
tumor, for detection of RET mutation can be useful
if other family members are to be screened for
potential germline abnormalities. Prospective
studies to evaluate the further utility of PTEN or
NTRK1 mutations have not been applied to
cytologic samples. However, given the relatively
low prevalence of these mutations, the expected
added value of these assays appears to be low.
Application of molecular testing to surgical
pathology has some value in the setting of an
atypical thyroid follicular lesion with patchy or
focal features suggesting papillary carcinoma,
where other methods (IHC and routine H&E)
are inconclusive.
Demonstration of a mutation such as RAS,
RET/PTC or BRAF might be of support in
making the diagnosis of carcinoma and giving
further appropriate treatment. Encapsulated
lesions like this have been shown to uniformly
contain the mutation, even though the cytologic

17


Toồng quan

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

dng xột nghim phõn t khỏc trong gii
phu bnh cú th cho hiu qu giỏn tip
trong iu tr. Phỏt hin t bin gen BRAF
giỳp d oỏn ỏp ng vi iu tr iod
phúng x v cú th h tr cỏc chn oỏn
thụng thng.

alterations are present only focally. Another use
of molecular evaluation in surgical pathology
might be in directing therapy more
individually. Being able to use BRAF-mutation
status to predict responsiveness to convention
radioiodine treatment could be a valuable
adjunct to conventional diagnostic reporting.

TểM TT V KT LUN

SUMMARY AND CONCLUSIONS

Cỏc ng t bin trong carcinụm tuyn
giỏp dng nhỳ (ch yu l gen
RET/RAS/BRAF/MAPK) v carcinụm tuyn

giỏp dng nang (hu ht l t bin gen RAS
hoc chuyn v PAX8/PPAR) cú s khỏc bit
v cú th loi tr ln nhau, m ra nhiu c
hi s dng cỏc du n phõn t khỏc nhau
giỳp ci thin chớnh xỏc ca chn oỏn.
Tuy nhiờn, nhy v c hiu ca cỏc
du n ny thng rt thp. Vic ỏnh giỏ
cỏc mu FNA tuyn giỏp khụng in hỡnh
vi mt bng cỏc xột nghim phõn t hu ớch
trong vic phõn loi nguy c ỏc tớnh ca
bnh. Xỏc sut ỏc tớnh ca mt trng hp cú
t bo hc khụng in hỡnh trờn FNA khong
40%. B xột nghim phõn t chn oỏn bao
gm BRAF, PAX8/PPAR, RAS, v RET cú
th xỏc nh nhúm nhng bnh nhõn ny vi
xỏc sut ỏc tớnh gn 100%, t ú giỳp nh
hng phu thut hoc ỏp dng cỏc phng
phỏp iu tr khỏc. Tuy nhiờn, trong cỏc xột
nghim phõn t, cú n 30% ung th tuyn
giỏp khụng phỏt hin c t bin, õy l
mt t l quỏ cao. Do ú, vn cũn li l
cn lm gỡ tip theo i vi cỏc mu t bo
hc khụng in hỡnh trong ú cỏc xột nghim
phõn t cho kt qu õm tớnh. Mt xột nghim
cú giỏ tr tiờn oỏn õm cao, vn rt cn thit
m ng cho cỏc nghiờn cu tip theo.

The distinct, and largely mutually exclusive,
mutation pathways observed in papillary thyroid
carcinomas

(mostly
RET/RAS/BRAF/MAPK)
versus follicular thyroid cancers (mostly due to
mutations of RAS or PAX8/PPAR translocation)
provides for opportunity to use various molecular
markers in improving diagnostic accuracy.
However, the sensitivity and specificity of
individual markers are often too low to provide
clinical utility as the combined negative predictive
values leave significant clinical gaps in
management. The evaluation of indeterminate
thyroid FNA cytologic samples with a panel of
molecular tests shows significant promise in
allowing further risk-stratification for presence of
malignancy. The probability of malignancy for
patients with an indeterminate FNA cytology is
about 40%(6). A molecular panel of tests including
BRAF, PAX8/PPAR RAS, and RET is able to
identify a group of these patients with virtually
100% probability of malignancy, thus helping to
expedite them towards surgical or other therapies.
However, in using such a molecular panel, up to
30% of thyroid cancers will have no mutation
detected
a proportion too high to ignore
(54)
clinically . Hence, the problem remains as to
what to do with indeterminate cytologic samples
that are negative for the panel of molecular tests
we have identified. A testing algorithm with a

very high negative predictive value is still needed
in order to inspire confidence in the path of
watchful waiting or inaction.

Ngi dch: ThS Trn Hng Giang,
ThS Phan ng Anh Th.
Hiu ớnh: ThS. on Th Phng Tho

18

Chuyờn Gii Phu Bnh


Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 *
2011
TI LIU THAM KHO
1.

2.

3.

4.
5.
6.

7.

8.

9.

10.

11.

12.

13.

14.

15.
16.

17.

National Cancer Institute, A Snapshot of Head and Neck and
Thyroid
Cancers,
accessed 22 Mar 2011.
Van Nostrand D (2006). Radionuclide imaging of thyroid nodules.in
Thyroid Cancer, Part III, pp 223-228, DOI: 10.1007/978-1-59259995-0_20
Miller JM, Hamburger JI, Kini S,(1979). Diagnosis of thyroid
nodules. Use of fine-needle aspiration and needle biopsy. JAMA
241 481-484.
Prinz RA, OMorchoe PJ, Barbato AL et al. (1983). Fine needle
aspiration biopsy of thyroid nodules. Ann Surg 198, 70-73.
Gharib H, Goellner JR,(1993). Fine-needle aspiration biopsy of
the thyroid: an appraisal. Ann Intern Med 118, 282-289.

Baloch ZW, Cibas ES, Clark DP, Layfield LJ, Ljung B, Pitman
MB, Abati A. (2008). The National Cancer Institute Thyroid fine
needle aspiration state of the science conference : A summation.
CytoJournal;5:6
Theoharis CG, Schofield KM, Hammers L, Udelsman R,
Chhieng DC. (2009). The Bethesda thyroid fine-needle aspiration
classification system: year 1 at an academic institution. Thyroid.
Nov;19(11):1215-23.
Nayar R, Ivanovic M. (2009). The indeterminate thyroid fineneedle aspiration: experience from an academic center using
terminology similar to that proposed in the 2007 National
Cancer Institute Thyroid Fine Needle Aspiration State of the
Science Conference. Cancer Cytopathol. Jun 25;117(3):195-202.
Nikiforov YE, Ohori NP. (2009). Follicular carcinoma, in
Diagnostic Pathology and Molecular Genetics of the Thyroid,
Nikiforov, Biddinger and Thompson eds. Wolters-Kluwer,
LWW, Baltimore, MD. pp132-3.
Harach HR, Soubeyran I, Brown A, et al. (1999). Thyroid
pathologic findings in patients with Cowden disease. Ann Diagn
Pathol; 3:331-340.
Ishikawa Y, Sugan H, Matsumoto T, et al. (1999). Unusual
feature of thyroid carcinomas in Japanese patients with Werner
syndrome and possible genotype-phenotype relations to cell
type and race. Cancer; 85:1345-1352.
Vitagliano D, Portella G, Troncone G, et al. (2006). Thyroid
targeting of the N-ras(Gln61Lys) oncogene in transgenic mice
results in follicular tumors that progress to poorly differentiated
carcinomas. Oncogene; 25:5467-5474.
French CA, Alexander EK, Cibas ES, et al. (2003). Genetic and
biological subgroups of low-stage follicular thyroid cancer. Am J
Pathol; 162:1053-1060.

Nikiforov MN, Lynch RA, Biddinger PW et al. (2003). RAS point
mutations and PAX8/PPAR
rearrangement in thyroid
tumors: evidence for distinct molecular pathways in thyroid
follicular carcinoma. J Clin Endocrinol Metab;88:2318-2326.
Shinohara M, Chung YJ, Saji M, et al. (2007). AKT in thyroid
tumorigenesis and progression. Endocrinology;148:942-947.
Wang Y, Hou P, Yu H, et al. (2007). High prevalence and mutual
exclusivity of genetic alterations in the phosphatidylinositol-3kinase/akt pathway in thyroid tumors. J Clin Endocrinol Metab;
92:2387-3290.
Wu G, Mambo E, Guo Z, et al. (2005). Uncommon mutation, but
common amplifications of the PIK3CA gene in thyroid tumors. J
Clin Endocrinol Metab;90:4688-4693.

Chuyờn Gii Phu Bnh

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.
29.

30.

31.

32.

33.

34.

Toồng quan

Halachmi N, Halachmi S, Evron E, et al. Somatic mutations of
the PTEN tumor suppressor gene in sporadic follicular thyroid
tumors. Genes Chromosomes Cancer 1998;23:239-243.
Maximo V, Botelho T, Capela J, et al. (2005). Somatic and
germline mutation in GRIM-19, a dual function gene involved in
mitrochondrial metabolism and cell death is linked to
mitochondrion-rich (Hurthle cell) tumours of the thyroid. Br J
Cancer; 92:1892-1898.
Nikiforov Y, Ohori P. (2009). Papillary carcinoma, in Diagnostic

Pathology and Molecular Genetics of the Thyroid, Nikiforov,
Biddinger and Thompson eds. Wolters-Kluwer, LWW,
Baltimore, MD. pp160-162.
Plail RO, Bussey HJ, Glazer G, et al. (1987). Adenomatous
polyposis: an association with carcinoma of the thyroid. Br J
Surg;74:377-380.
Uchino S, Noguchi S, Kawamoto H, et al. (2002). Familial
nonmedullary thyroid carcinoma characterized by multifocality
and a high recurrence rate in a large study population. World J
Surg;26:897-902.
McKay JD, Lesueur F, Jonard L, et al. (2001). Localization of a
susceptibility gene for familial nonmedullary thyroid carcinoma
to chromosome 2q21. Am J Hum Genet; 69:440-446.
Roque L, Nunes VM, Ribeiro C, et al. (2001). Karyotypic
characterization of papillary thyroid carcinomas. Cancer;92:25292538.
Frattini M, Ferrario C, Bressan P, et al. (2004). Alternative
mutations of BRAF, RET and NTRK1 are associated with similar
but distinct gene expression patterns in papillary thyroid cancer.
Oncogene;23:7436-7440.
Kimura ET, Nikiforova MN, Zhu Z, et al. (2003). High
prevalence of BRAF mutations in thyroid cancer: genetic
evidence for constituitive activation of the RET/PTC-RAS-BRAF
signaling pathway in papillary thyroid carcinoma. Cancer
Res;63:1454-1457.
Nikiforova MN, Kumura ET, Gandhi M, et al. (2003). BRAF
mutations in thyroid tumors are restricted to papillary
carcinomas and anaplastic or poorly differentiated carcinomas
arising from papillary carcinomas. J Clin Endocrinol
Metab;88:5399-5404.
Nikiforov Y, Ohori P. op cit. p.164.

Nikiforov Y, Rowland JM, Bove KE, et al. (1997). Distinct pattern
of ret oncogene rearrangements in morphological variants of
radiation-induced and sporadic thyroid papillary carcinomas in
children. Cancer Res;57:1690-1694.
Zhu Z, Gandhi M, Nikiforovna MN, et al. (2003). Molecular
profile and clinical-pathologic features of the follicular variant of
papillary thyroid carcinoma. An unusually high prevalence of
ras mutations. Am J Clin Pathol;120:71-77.
Hara H, Fulton N, Yashiro T, et al. (1994). N-ras mutation: an
independent prognostic factor for aggressiveness of papillary
thyroid carcinoma. Surgery;116:1010-1016.
Pierotti MA, Bongarzone I, Borello MG, et al. (1996).
Cytogenetics and molecular genetics of carcinomas arising from
thyroid epithelial follicular cells. Genes Chromosomes Cancer;16:114.
Russell JP, Powell DJ, Cunnane M, et al. (2000). The TRK-T1
fusion protein induces neoplastic transformation of thyroid
epithelium. Oncogene;19:5729-5735.
Giordano TJ, Kuick R, Thomas DG, et al. (2005). Molecular
classification of papillary carcinoma: distinct BRAF, RAS and

19


Toồng quan

35.

36.

37.

38.
39.

40.

41.

42.

43.

44.

45.

46.

47.

48.
49.

20

Y Hoùc TP. Ho Chớ Minh * Taọp 15 * Ph bn Soỏ 2 * 2011

RET/PTC mutation-specific gene expression profiles discovered
by DNA microarray analysis. Oncogene;24:6646-6656.
Chevillard S, Ugolin N, Vielh P, et al. (2004). Gene expression

profiling of differentiated thyroid neoplasms: diagnostic and
clinical implications. Clin Cancer Res;10:6586-6597.
Chen YT, Kitabayashi N, Zhou XT, et al. (2008). MicroRNA analysis
as a potential diagnostic tool for papillary thyroid carcinoma. Mod
Pathol; 21: 11391146.
Nikiforova MN, Tseng GC, Steward D, et al. (2008). MicroRNA
expression profiling of thyroid tumors: biological significance
and diagnostic utility. J Clin Endocrinol Metab;93:1600-1608.
Rosai J, Carcangiu ML, DeLellis RA (1992). Tumors of the Thyroid
Gland. Washington, DC. Armed Forces Institute of Pathology:.
Dobashi Y, Sugimura H, Sakamoto A, et al. (1994). Stepwise
participation of p53 gene mutation during dedifferentiation of
human thyroid carcinomas. Diagn Mol Pathol;3:9-14.
Seethala RR and Nikiforov YE (2009). Anaplastic
(undifferentiated) carcinoma, in Diagnostic Pathology and
Molecular Genetics of the Thyroid, Nikiforov, Biddinger and
Thompson eds. Wolters-Kluwer, LWW, Baltimore, MD.p 228.
Donghi R, Longoni A, Pilotti S, et al. (1993). Gene p52 mutations
are restricted to poorly differentiated and undifferentiated
carcinomas of the thyroid gland. J Clin Invest; 91:179-184.
Garcia-Rostao G, Tallini G, Herraro A, et al. (1999). Frequent
mutation and nuclear localization of beta-catenin in anaplastic
thyroid carcinoma. Cancer Res; 59:1811-1815.
Mulligan LM, Kwok JB, Healey CS, et al. (1993). Germ-line
mutations of the RET proto-oncogene in multiple endocrine
neoplasia type 2A. Nature; 363:458-460.
Donis-Keller H, Dou S, Chi D, et al. (1993). Mutuations in the
RET proto-oncogene are associated with MEN 2A and FMTC.
Hum Mol Genet; 2:851-856.
Eng C, Smith DP, Mulligan LM, et al. (1994). Point mutation

within the tyrosine kinase domain of the RET proto-oncogene in
multiple endocrine neoplasia type 2B and related sporadic
tumours. Hum Mol Genet; 3:237-241.
deGroot JW, Links TP, Plukker JT, et al. (2006). RET as a
diagnostic and therapeutic target in sporadic and hereditary
endocrine tumors. Endocr Rev; 27:535-560.
Biddinger PW (2009). Medullary Carcinoma in Diagnostic
Pathology and Molecular Genetics of the Thyroid, Nikiforov,
Biddinger and Thompson eds. Wolters-Kluwer, LWW,
Baltimore, MD.pp 251-254.
DeLellis RA, Lloyd RV, Heitz PU, et al. (2004) .eds. Pathology and
Genetics of Tumours of Endocrine Organs. Lyons: IARC Press.
Orru G, Coghe F, Gavina F, et al. (2010). Rapid multiplex realtime PCR by molecular beacons for different BRAF allele

50.

51.

52.

53.

54.

55.
56.

57.

58.

59.

60.
61.

detection in papillary thyroid carcinoma. Diag Mol Pathol;
19(1):1-8.
Feilchenfeldt J, Totsch M, Sheu SY, et al. (2003). Expression of
galectin-3 in normal and malignant thyroid tissue by quantitative
PCR and immunohistochemistry. Mod Pathol; 16(11):1117-1123.
Savagner F, Rodien P, Reynier P, et al. (2002). Analysis of Tg
transcripts by real-time TR-PCT in the blood of thyroid cancer
patients. J Clin Endocrinol Metab; 87(2):635-639.
Salvatore G, Giannini R, Faviana P, et al. (2004). Analysis of
BRAF point mutation and RET/PTC rearrangement refines the
fine-needle aspiration diagnosis of papillary thyroid carcinoma. J
Clin Endocrinol Metab; 89:5175-5180.
Cohen Y, Rosenbaum E, Clark DP, et al. (2004). Mutational
analysis of BRAF in fine needle aspiration biopsies of the thyroid:
a potential application for the preoperative assessment of thyroid
nodules. Clin Cancer Res; 10:2761-2765.
Riesco-Eizaguirre G, Gutierrez-Martinez P, Garcia-Cabesas MA,
et al. (2006). The oncogene BRAF V600E is associated with a
high risk of recurrence and less differentiated papillary thyroid
carcinoma due to the impairment of Na+/I- targeting to the
membrane. Endocr Relat Cancer; 13:257-269.
Sherman SI (2010). Targeted therapy of thyroid cancer. Biochem
Pharmacol; 80(5):592-601.
Nikiforov YE, steward DL, Robinson-Smith TM, et al. (2009).

Molecular testing for mutations in improving the fine-needle
aspiration diagnosis of thyroid nodules. J Clin Endocrinol Metab;
94:2092-2098.
Chudova D, Wilde JI, Wang ET et al. (2010). Molecular
classification of thyroid nodules using high-dimensionality
genomic data. J Clin Endocrinol Metab. Dec; 95(12):5296-304.
Haugen BR (2010). Development of a novel molecular classifier
to accurately identify benign thyroidnodules in patients with
indeterminate FNA cytology (abstract) 15 Sept 2010, 14th
International Thyroid Congress, Paris
Grogan RH, Mitmaker EJ, Clark OH, The Evolution of Biomarkers in
Thyroid CancerFrom Mass Screening to a Personalized
Biosignature. Cancers 2010; 2: 885-912.
Nikiforova MN, Nikiforov YE. (2009). Molecular diagnostics and
predictors in thyroid cancer. Thyroid; 19(12): 1351-1361.
Nikiforov YE, Steward DL, Robinson-Smith TM, et al. (2009).
Molecular testing for mutations in improving the fine-needle aspiration
diagnosis of thyroid. J Clin Endocrinol Metab. 94(6):2092-8.

Chuyờn Gii Phu Bnh