Study on rate and some risk factors for egfr mutation in 152 patients with lung adenocarcinoma at Bachmai hospital

Journal of military pharmaco-medicine No7-2016

STUDY ON RATE AND SOME RISK FACTORS FOR EGFR
MUTATION IN 152 PATIENTS WITH LUNG ADENOCARCINOMA
AT BACHMAI HOSPITAL
Nguyen Thi Lan Anh*; Nguyen Huy Binh*
Mai Trong Khoa*; Dong Khac Hung**
SUMMARY
A study on the rate and some risk factors causing gene EGFR mutation in lung adenocarcinoma
was conducted at Bachmai Hospital. Objectives: To determine the rate and risk factors for
EGFR gene mutations on 152 patients with lung adenocarcinoma at Bachmai Hospital. Subjects
and methods: 152 patients with lung adenocarcinoma diagnosed by histopathological method;
the mutation of EGFR gene was identified by assay Strip methods. Results: 60 lung cancer
patients (39.5%) were diagnosed adenocarcinoma. The rate of mutations was found at exons
18, 19, 20, 21 of the EGFR gene. The exon mutations were classified as follows: G719S
mutation, G719C (exon 18), LREA deletion (exon 19), T790M (exon 20) and L858R; L861Q
(exon 21) were 3.2%, 55.6%, 4.8% and 36.4%, respectively. The possibility of EGFR gene
mutations in female patients was 2.9 times as high as male patients (95%CI 1.4 to 6.1) and
3.4 fold higher compared to patients with history of smoking with 95%CI: 1.6 to 6.2. Conclusions:
Among 152 patients with lung adenocarcinoma who were treated at Bachmai Hospital, we found
the rate of EGFR gene mutations was 39.5%. The mutations of EGFR gene were more common
in women and non-smoking patients.
* Key words: Lung adenocarcinoma; EGFR gene mutation; Gender; Smoking.

INTRODUCTION
In Vietnam, lung cancer is one of the
most common malignant diseases in both
men and women and is also the leading
cause of death from cancer. The prevalence
of lung cancer is 30.7/100,000 in men and
6.7/100,000 in women [1]. Disease-free

survival and overall survival rate of lung
cancer patients is still very low, although
there have been many advances in
diagnosis and treatment [3, 4, 5]. Currently,
adenocarcinoma is the most common
type of lung cancer in Vietnam and many
other countries at the rate of 50 - 70% [2].
In many recent studies in the world as

well as in Vietnam, the effectiveness of
treatment for non-small cell lung cancer
by using drugs inhibit tyrosine kinase
activity (TKI - Tyrosine kinase inhibitors)
of epithelial growth factor receptor
(EGFR) was confirmed. Gefitinib and
erlotinib are used as target therapy. These
studies also show the therapeutic effects
of the drugs depends on mutations in
exons 18, 19, 20, and 21 of EGFR gene
due to the creation of EGFR protein that
has high affinity for TKI inhibitors, therefore
patients with non-small cell lung cancer
bearing EGFR gene mutations usually
respond well to target treatment.

* Bachmai Hospital
** Military Medical University
Corresponding author: Dong Khac Hung ()

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Journal of military pharmaco-medicine No7-2016
Thereby, mutations of EGFR gene is
an important evidence for indications of
the target therapy for patients with lung
adenocarcinoma. There are now a variety
of methods of detecting EGFR gene
mutations such as gene sequencing or
Scopion ARMS... [3]. At the Center for
Nuclear Medicine and Oncology, Bachmai
Hospital, testing of EGFR gene mutation
with the assay technique Vienalab Strip
(Republic of Austria) has been applied
since October 2014. This technique combines
PCR with specific mixed probes to detect
16 mutations of the EGFR gene [6].
Currently, there are not many studies
on the rate of EGFR gene mutation and
their risk factors (gender and smoking status)
on the patients with adenocarcinoma.
This study was conducted aiming:
To determine the rate and risk factors
for EGFR gene mutations on 152 patients
with lung adenocarcinoma treated at Bachmai
Hospital.
SUBJECTS AND METHODS
1. Subjects.
152 patients with lung adenocarcinoma
were diagnosed by histopathology at the

Center for Nuclear Medicine and Oncology,
Bachmai Hospital. Specimens were

collected by biopsy of lymph node or
pleural, or from tumor tissue after surgery.
- Samples were analyzed for EGFR
gene mutations at Gene Therapy Unit,
Centre for Nuclear Medicine and Oncology
and the Center for Histopathology,
Bachmai Hospital.
- Research period: from November, 2014
to September, 2015.
2. Methods.
- This is a prospective, descriptive and
cross-sectional study.
* Gathering information about age,
gender, smoking status of patients under
a unified form.
* The process of EGFR gene mutation
test includes 4 main stages:
- Separation of DNA from tissue processing
formalin - buried paraffin (FFPE) by kit
QIAamp DNA FFPE Tissue specificity
(Qiagen).
- Amplification gene segments by PCR
according to StripAssay EGFR kit (ViennaLab).
- Mixed amplification products with specific
probes are distributed on test strip.
- Analysis of results.
* Processing data: using SPSS 16.0

software.

RESULTS
1. Gender, age and smoking status.
Table 1: Characteristics of the subjects.
Gender

Age (year)

Smoking status

Total

Male

Female

< 60

≥ 60

Yes

No

n

108

44

75

77

85

67

152

%

71.7

28.3

49.3

50.7

55.9

44.1

100.0

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Journal of military pharmaco-medicine No7-2016
Male/female ratio was 2.46/1. Mean age was 59.6 ± 9.9. The lowest was 32 years
old and the highest age was 80. More than 50% of the patients have been smoking
(55.9%); the rest gave up smoking (44.1%).
2. Rate of EGFR gene mutation.
* Proportion of EGFR gene mutations in lung cancer patients with adenocarcinoma
(n = 152):
Mutation: 60 patients (39,5%); no mutation: 92 patients (60,5%).
* Number of exon mutations:
95.0% of cases (57 patients) had mutations in only one exon of the gene EGFR,
but there were 3 cases (5.0%), who had mutations in three different exons.
Table 2: Rate of exon mutations.
Location

Sorts of mutation

n

%

Exon18

G719S; G719C

2/63

3.2

Exon 19

Delete (LREA)

35/63

55.6

Exon 20

T790M

3/63

4.8

Exon 21

L858R; L861Q

23/63

36.4

Because 3 cases had two mutations, the total number of mutations in this study
was 63.
The deletion Exon 19 mutation was the most common (55.6%), followed by the L858R
point mutation in exon 21 (36.4%).
Table 3: Relationship between the EGFR gene mutation, gender and smoking status.
EGFR (+) (n = 60)

EGFR (-) (n = 92)

p

n

%

n

OR (95%CI)

%

Gender
Female (n = 43)

25

58,1

18

41,9
< 0,01

Male (n = 109)

35

32,1

74

67,9

2,9
(1,4 - 6,1)

Smoking
No (n = 85)

44

51,8

41

48,2
< 0,001

Yes (n = 67)

16

23,9

51

76,1

3,4

(1,6 - 6,2)

The possibility of EGFR gene mutations in male patients was 2.9 times as high as it
was in female (95%CI: 1.4 to 6.1) and 3.4 times compared to patients with a history of
smoking (95%CI: 1.6 to 6.2).
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Journal of military pharmaco-medicine No7-2016
DISCUSSION
1. The rate of EGFR gene mutations
in 152 patients with lung adenocarcinoma.
The results showed that 60 patients
(38.4%) had EGFR gene mutations at
exon 18, 19, 20, 2. The proportion of
G719S mutations (exon 18), delete
paragraph LREA (exon 19), T790M (exon
20) and L858R (exon 21) were 3.2%,
55.6%, 4.8% and 36.4%, respectively.
The rate of EGFR gene mutation in our
study was lower than Pioneer’s (64.2%)
[7], but higher than Ha's findings (this rate
was 35.7%) [3]. This difference may be
due to the fact that patients in Pioneer's
research were in stage III, IV. Moreover,
samples in this study were collected from
the tissue of primary tumors. Our study
was conducted on the patients of all
stages I, II, III and IV; and they were not
only the tissue of primary tumors but

also the metastases.
According to foreign literature, although
there are about 40 mutations of EGFR as
a role of the pathogenesis and they
proved to be an effective target treatment,
mutations at exon 19 LREA L858R and
exon 21 are the most two common types
(accounting for 85 - 90%) EGFR gene
mutations related to drug responsiveness
of treatment [3]. These are two types of
mutations that increase the sensitivity of
tumors to TKI drugs. The other mutations
occupying a very small percentage as the
mutations at exon 18, exon 19 and exon
21 helps increase sensitivity, but mutations
at exon 20 (T790M) makes tumors resistant
to target treatment. Our results were only
at beginning step, but had a very important

role in the diagnosis, treatment and prognosis
of lung adenocarcinoma in Vietnam.
* Risk factors for age and smoking
addiction for EGFR gene mutations:
Many researchers in the world and
Vietnam indicate strong relation between
EGFR gene mutation status with gender,
race and smoking status in patients with
lung adenocarcinoma [3, 7]. The results
of this study (table 2) showed the possibility
of EGFR gene mutations in female patients

2.9 times higher than male patients (95%CI:
1.4 to 6.1) and the possibility of mutation
EGFR gene in non-smoking patients was
3.4 times higher than patients who have
been smoking (95%CI: 1.6 to 6.2).
Our findings and other studies’ in Asia
(Shigemitsu, 2006...) pointed out the
differences in lung adenocarcinoma in
compared to the other regions in the
world. EGFR gene mutation is more
prominent in non-smoking female patients
[7, 8]. It is also advantageous to help lung
cancer patients with adenocarcinoma in
Asia and Vietnam be indicated for the
target treatment and prolong the survival.
CONCLUSION
Throughout the study on 152 patients
with lung adenocarcinoma with EGFR gene
mutations at the Center of Nuclear Medicine
and Oncology, Bachmai Hospital, we drew
some conclusions:
- The rate of mutations at exon 18, 19,
20, 21 of the EGFR gene was 39.5%. The
rates of mutation G719S; G719C (exon 18),
LREA deletion (exon 19), T790M (exon 20)
and L858R; L861Q (exon 21) were 3.2%,
55.6%, 4.8% and 36.4%, respectively.
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Journal of military pharmaco-medicine No7-2016
- The possibility of EGFR gene mutations
in women was 2.9 times higher than men
(95%CI: 1.4 to 6.1) and 3.4 times higher
than the group of patients with a history of
smoking (95%CI: 1.6 to 6.2).
REFERENCES
1. Globocan 2012. Cancer Incidence. IARC.

multiethnic Malaysian patient population. Asian
Pac J Cancer Prev. 2014, 15 (1), pp.321-326.
5. Liam CK, Pang YK, Poh ME. EGFR
mutations in Asian patients with advanced
lung adenocarcinoma. J Thorac Oncol. 2014,
9 (9), pp:e70-71.
6. EGFR StripAssay®www.viennalab.com/
products/cancer/egfr_stripassay

3. Ha Ng M. Determine gene EGFR mutations
in patients with non-small cell lung cancer.
Journal of Medical Research. Hanoi. 2013, 17 (1),
pp.34-37.

7. Shi Y, Au JS, Thongprasert S, Srinivasan S,
Tsai CM, Khoa MT, Heeroma K, Itoh Y, Cornelio G,
Yang PC. A prospective, molecular epidemiology
study of EGFR mutations in Asian patients
with advanced non-small-celllung cancer of
adenocarcinoma histology (PIONEER). J Thorac
Oncol. 2014, 9 (2), pp.154-162.

4. Liam CK, Leow HR, How SH, Pang YK,
Chua KT, Lim BK, Lai NL, Kuan YC, Pailoor J,
Rajadurai P. Epidermal growth factor receptor
mutations in non-small cell lung cancers in a

8. Shigematsu H, Gazdar AF. Somatic
mutations of epidermal growth factor receptor
signaling pathway in lung cancers. Int J Cancer.
2006, 118 (2), pp.257-262.

2. Jemal A, Bray F, Ward E et al. Global
cancer statistics, CA Cancer J Clin. 2011, 61
(2), pp.69-90.

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