Prognosis significance of HER-2/neu overexpression/amplification in Chinese patients with curatively resected gastric cancer after the ToGA clinical trial

Abstract

Background
HER-2/neu-targeted therapy has been successfully used in advanced gastric cancer, but the role of HER-2/neu in the prognosis of gastric cancer is not yet clear. In this study, we investigated the correlation between HER-2/neu expression and amplification as well as their association with clinic outcomes in patients with curatively resected gastric cancer.

Methods
We constructed tissue microarray blocks containing >70% of gastric cancer tissue and matched adjacent normal gastric tissue for 227 patients. Expression of the HER-2/neu protein in these specimens was analyzed using immunohistochemical staining. Amplification of HER-2/neu was also analyzed for the same samples using fluorescence in situ hybridization. Data on clinicopathological features and relevant prognostic factors in these patients were analyzed.

Results
Of the 227 gastric cancer samples, 11.89% were positive for HER-2/neu overexpression/amplification under the new scoring system. HER-2/neu overexpression/amplification was closely correlated to the Lauren type, degree of differentiation, tumor size and lymph node metastasis. HER-2/neu overexpression/amplification predicted poor survival in univariate analysis but not in a Cox proportional hazards model.

Conclusion
HER-2/neu overexpression/amplification was not an independent predictor for survival in patients with curatively resected gastric cancer.

Full text

R E S E A R C H Open Access
Prognosis significance of HER-2/neu
overexpression/amplification in Chinese patients
with curatively resected gastric cancer after the
ToGA clinical trial
Fei Zhou
1
, Ning Li
1
, Weihua Jiang
1
, Zhaolai Hua
2
, Lin Xia
3
, Qingyi Wei
4
and Liwei Wang
1*
Abstract
Background: HER-2/neu-targeted therapy has been successfully used in advanced gastric cancer, but the role of
HER-2/neu in the prognosis of gastric cancer is not yet clear. In this study, we investigated the correlation between
HER-2/neu expression and amplification as well as their association with clinic outcomes in patients with curatively
resected gastric cancer.
Methods: We constructed tissue microarray blocks containing >70% of gastric cancer tissue and matched adjacent
normal gastric tissue for 227 patients. Expression of the HER-2/neu protein in these specimens was analyzed using
immunohistochemical staining. Amplification of HER-2/neu was also analyzed for the same samples using
fluorescence in situ hybridization. Data on clinicopathological features and relevant prognostic factors in these
patients were analyzed.
Results: Of the 227 gastric cancer samples, 11.89% were positive for HER-2/neu overexpression/amplification under
the new scoring system. HER-2/neu overexpression/amplification was closely correlated to the Lauren type, degree
of differentiation, tumor size and lymph node metastasis. HER-2/neu overexpression/amplification predicted poor
survival in univariate analysis but not in a Cox proportional hazards model.
Conclusion: HER-2/neu overexpression/amplification was not an independent predictor for survival in patients with
curatively resected gastric cancer.
Keywords: FISH, Gastric cancer, HER-2/neu, IHC, Prognosis
Background
Although the incidence of gastric cancer is decreasing
worldwide, it is still relatively high in China with 420,000
newly diagnosed patients each year. The mortality rate of
gastric cancer in China ranks third among all cancer
deaths, with 320,000 patients for the period of 2004 to 2005
[1]. Although there has been great improvement in the
early diagnosis of gastric cancer, in combination with the
recent progress of surgical techniques and comprehensive
use of chemotherapy and radiotherapy, the 5-year survival
rate for gastric cancer remains as low as 20% to 30% [2].
Targeted therapy is a new trend in cancer treatment to
improve overall survival in patients with cancer. In
regard to gastric cancer, molecularly targeted therapy is
also gaining status. Antiangiogenic therapy and anti-
epidermal growth factor receptor therapy have emerged
as a new hope [3], especially the anti-HER-2 drug, tras-
tuzumab. According to the ToGA clinical trial reported
in 2010 [4], patients with HER-2/neu overexpression
receiving chemotherapy and trastuzumab had a signifi-
cant longer median overall survival of 13.8 months
without any additional adverse side effects. Shitara et al.
also reported that patients who were HER-2-positive
with advanced gastric cancer had a better prognosis than
patients who were negative for HER-2 when treated with
trastuzumab [5]. All these indicate that the HER-2/neu-
* Correspondence: yzwlw@yahoo.com
1
Department of Oncology, Shanghai First People’s Hospital Affiliated
Shanghai Jiaotong University, Shanghai 200080, China
Full list of author information is available at the end of the article
WORLD JOURNAL OF
SURGICAL ONCOLOGY
© 2012 Zhou et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Zhou et al. World Journal of Surgical Oncology 2012, 10:274
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targeted therapy has great potential in improving the
treatment of gastric cancer.
Oncogene HER-2/neu was originally discovered in che-
mically induced rat neuroglioblastomas [6] and is located
on chromosome 17q21 and codes for a transmembrane
glycoprotein of 185kD. The protein consists of an extra-
cellular ligand-binding domain of 653 amino acids, a
single membrane-spanning region of 654 to 675 amino
acids, and a cytoplasmic protein tyrosine kinase domain of
675 to 1,255 amino acids. It is one of the members of the
human epidermal growth factor receptor (HER) family
that includes HER-1 (epidermal growth factor receptor),
HER-2/neu, HER-3 and HER-4 [7]. Among these, HER-2/
neu plays an important role in normal development, dif-
ferentiation and apoptosis of the cell. Gene amplification
and overexpression of HER-2/neu have been reported in
many cancer types, including that of the ovary [8], lung
[9] and prostate [10], in addition to the breast [11]. For
example, it has been shown that HER-2/neu overexpres-
sion was detected in about 10% to 34% of invasive breast
cancers and was associated with poor prognosis. Although
HER-2/neu is considered an independent prognostic fac-
tor for breast cancer, its prognostic role in gastric cancer
still remains controversial because several studies have
generated conflicting results [12-16].
To assess the association between the status of Her-2/
neu and prognosis of Chinese patients with gastric cancer,
we conducted a (we think “the”is better, it means this
study) study to examine both expression and amplification
of Her-2/neu in tumors of curatively resected gastric can-
cer and correlated these measurements to the clinico-
pathological and prognostic outcomes of the patients.
Methods
Patients and clinicopathological information collection
A total of 227 patients with gastric cancer from the
pathology archives of the Yangzhong People’s Hospital
were included in this study between 2002 and 2004. All
of the patients (except those classified as T1N0M0) had
undergone curative surgery and received a similar adju-
vant regimen of chemotherapy (5-fluorouracil and cis-
platin). Clinicopathological variables including age, sex,
histologic type and pathologic stage were collected by
reviewing medical charts and pathology records. Among
these patients, 157 were men and 70 were women, with
an age range between 24 and 79 years old (a median of
60 years old). Tumor sites included 28 antrum, 50
corpus and 149 cardia. Patients were followed from the
date of surgery until death, or censored on 31 December
2008, which resulted in a follow-up period of 1 to 108
months (a median of 64 months). The study was
approved by our Institutional Ethnic Committee (equiva-
lent to an institutional review board). As this was a
retrospective study using archive tissue specimens, the
Institutional Ethnic Committee waived the need for
written informed consent.
Tissue microarray construction
In brief, H & E-stained sections were made from primary
tumor blocks to define two representative tumor regions
and adjacent normal gastric tissues. Representative tumor
regions were defined as tumor solid areas containing more
than 75% cancer cells without necrosis. Normal gastric
tissues were randomly selected adjacent to a tumor with a
distance of more than 5 cm, avoiding the bleeding areas.
Tumor typing and grading were performed according to
Lauren and the World Health Organization (WHO) cri-
teria. All patients with gastric cancer were staged using
the seventh edition of the International Union Against
Cancer Tumor-Node-Metastasis (TNM) staging system.
Tissue cylinders (1.5 mm in diameter) were then punched
from the defined regions of the block using a tissue micro-
arrayer (Gentury, IL, USA) and brought into recipient
paraffin blocks. Two sets of three paraffin-embedded
tissue microarray (TMA) blocks were made. Sections of
the resulting TMA blocks were transferred to glass slides.
Figure 1 Immunohistochemical staining for HER-2/neu expression in tumor samples from patients with gastric cancer. (A) Membrane
staining in normal gastric epithelium for HER-2/neu (0+). (B) Faint membrane staining in >10% tumor cells (1+). (C) Moderate complete membrane
staining in >10% tumor cells (2+). (D) Strong complete membranes staining in >10% tumor cells (3+). (H&E; original magnification, ×4, ×40).
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There were a total of two sets of TMA, containing 227
tumor tissue spots and 135 adjacent normal gastric tissue
spots each, available for this study (collaborating with
Shanghai Biochip, Shanghai, China).
Immunohistochemistry
Immunohistochemistry (IHC) staining for HER-2/neu was
conducted on TMA sections. Formalin-fixed, paraffin-
embedded sections were dewaxed in xylene and rehy-
drated through graded alcohol. Endogenous peroxidase
activity was quenched by 3% hydrogen peroxide, then the
section was washed in water and the antigen retrieved and
placed in citrate buffer. The sections were washed with
phosphate-buffered saline, pH 7.2. The primary monoclo-
nal mouse antibody against human HER-2/neu protein
(MAB-0198, Maxin Biotech, Fujian, China) was applied
for 1 hour in the incubator at 37°C. Anti-HER-2 anti-
body (Dako REAL, En Vison, HRP Rabbit/Mouse, Dako,
Carpinteria, CA, USA) was then applied. Diaminobenzi-
dine solution was used as a chromogen.
Fluorescence in situ hybridization
Fluorescence in situ hybridization (FISH) analysis was ap-
plied to the sections. Amplification of the HER-2gene was
determined by FISH using a Vysis dual-color, dual-fusion
translocation probe set purchased from Abbott Molecular
Inc. (DesPlaines, IL, USA). In brief, sections were deparaf-
finized, dehydrated, and then incubated in 30% sodium bi-
sulfate for 20 min at 45°C. After being washed in 2× SSC
Sodium citrate-Hydrochloric acid Buffer solution }, slides
were treated with proteinase K at 37°C for 25 min. Then
hybridization was carried out overnight at 42°C in a
humid chamber, followed by post-hybridization washes in
denaturation solution and 0.1% NP-40 with 2×SCC
Sodium citrate-Hydrochloric acid Buffer solution }at room
temperature. Finally, slides were washed and counter-
stained with 0.2 μmol/L 40-6-diamidino-2-phenylindole
and examined under a confocal laser scanning microscope
LSM 510 (Carl-Zeiss, Jena, Germany).
Scoring of immunohistochemistry and fluorescence in situ
hybridization
HER-2 immunostaining was scored using the following
scoring system adopted by Hofmann in the ToGA clin-
ical trial: score 0, no membrane staining or <10% of cells
stained; 1+, faint/barely perceptible membranous re-
activity in 10% of cells or higher or reactivity in only part
of the cell membrane; 2+, weak to moderate complete or
basolateral membranous reactivity in 10% of tumor cells
or higher; and 3+, strong complete or basolateral mem-
branous reactivity in 10% of tumor cells or higher.
Scores of 0 and 1+ were considered negative for HER-2/
neu overexpression, and scores of 3+ were considered
positive. Scores of 2+ were considered overexpression if
Table 1 Comparison of clinicopathological features
according to HER-2 overexpression/amplification
Clinicopathological
features
HER-2 overexpression/amplification
HER-2/neupositive
(n = 27)
HER-2/neunegative
(n = 200)
P
Age 0.151
<65 years 18 96
≥65 years 9 104
Sex 0.765
male 18 139
female 9 61
Lauren 0.001
intestinal 26 118
diffuse 0 49
mixed 1 33
WHO classification 0.001
W/D 9 24
M/D 16 97
P/D 2 79
Tumor size 0.002
≥5cm 18 72
<5 cm 9 128
Tumor location 0.258
cardia 21 128
corpus 5 45
antrum 1 27
Invasion depth 0.322
T1 1 19
T2 4 32
T3 22 149
Lymph node 0.022
present 20 118
absent 7 82
TNM stage 0.320
I343
II 6 52
III 18 105
Vessel invasion 0.241
present 4 16
absent 23 184
Borrmann 0.133
I426
II 17 102
III 6 64
IV 0 8
M/D: moderately differentiated; P/D: poorly differentiated; W/D: well differentiated
WHO: World Health Organization.
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FISH confirmed amplification [4,17]. Gene amplification
was defined as cancer cell nuclei exhibiting a ratio of
HER-2/neu to CEP17 (centromeric probe 17) ≥2, or
when an HER-2/neu signal cluster was observed.
All samples on the TMA sections from gastric cancers
were reviewed by two pathologists independently to
determine scores of IHC. For discordant opinions, the
samples were re-examined by the two pathologists to
achieve a consensus score.
Statistical analysis
Categorical data were analyzed using χ
2
statistics. The
probability of survival by different subgroups was calcu-
lated using the Kaplan-Meier method, and statistical
significance was analyzed by using the log-rank test.
Multivariate analysis was carried out by using the Cox
proportional hazards model with adjustment for covari-
ates to identify primary prognostic indicators that were
independently associated with survival. All statistics
were two-sided, at a significant level of P<0.05, by using
the SPSS statistical software package for Windows
(release 13.0, SPSS, Inc., Chicago, IL, USA).
Results
HER-2/neu protein expression status and clinicopathological
variables in 227 cases of gastric carcinoma
HER-2/neu protein expression in gastric cancer tissues
was determined by IHC for 227 patients. As shown in
Figure 1, the immunostaining revealed that expression
was detectable only in the cell membranes of tumor cells
but not in the adjacent normal gastric epithelial cells. Of
these 227 tumors, 189 cases (83.41%) scored 0; 4 cases
(1.75%) scored 1+; 11 cases (4.80%) scored 2+; and 23
cases (10.04%) scored 3+. Among 11 cases of 2+, 4 cases
(36.4%) were positive for amplification. Therefore, 27
cases (11.89%) had HER-2/neu overexpression. The cor-
relation between HER-2/neu protein expression levels and
clinicopathological variables are summarized in Table 1.
Compared with tumors without overexpression, tumors of
gastric cancer with HER-2/neu overexpression showed
predominantly well- or moderately differentiated histology
by the WHO classification (P<0.05) and an intestinal type
histology by the Lauren classification (P<0.05). HER-2/
neu overexpression was also associated with tumor size
and lymph node metastasis (P<0.05). However, no differ-
ences in the expression levels by age, sex, tumor location,
invasion depth, TNM stage, vessel invasion or Borrmann
type were found for all (P>0.05).
HER-2/neu amplification status in 227 cases of gastric
carcinoma
In the FISH analysis, gene amplification was detected in
all tumor samples (Figure 2). When the results of FISH
and IHC were compared (Table 2), IHC 0+ or 1+ samples
did not exhibit amplification (0%), whereas 23 tumors
with 3+ immunostaining all showed amplification (100%).
Nevertheless, among the 11 tumors with 2+ immunos-
taining, only showed amplification (36.37%). There were
27 cases (11.89%) of HER-2/neu amplification in the same
tumors that had overexpression.
Survival analysis
Survival analysis was performed on these 227 patients.
Patients with tumors with HER-2/neu overexpression/
amplification showed lower 5-year survival rates than
those without (27.3% versus 42.8%, P<0.05). In our
univariate analysis, Lauren classification, differentiated
Figure 2 Fluorescence in situ hybridization of HER-2/neu amplification (original magnification, ×60).
Table 2 Correlation between overexpression and
amplification for HER-2/neu
FISH IHC
0
n = 189
1+
n=4
2+
n=11
3+
n=23
Total
n = 227
No amplification 189 4 7 0 227
Amplification 0 0 4 23 27
Amplification rate (%) 0 0 36.40 100 11.89
FISH: fluorescence in situ hybridization; IHC: immunohistochemistry.
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histology, tumor size (≥5 cm), invasion depth, lymph
node metastasis, TNM stage, vessel invasion and HER-2/
neu overexpression/amplification were all associated
with poor survival (P<0.05) (Table 3). A final multivari-
ate Cox proportional hazards model identified Lauren
classification, vessel invasion, TNM stage and tumor size
(≥5cm) as bearing prognostic importance (P<0.05);
however, HER-2/neu overexpression/amplification was
not an independent prognostic factor in this model
(Table 3).
Discussion
Since the publication of the ToGA study, the standard for
HER-2/neu overexpression has changed from IHC 2+ or
3+ to IHC 3+ or IHC 2+ with amplification, which means
that conclusions reached before in the literature should be
assessed again and could be different according to the
new criteria. In our study, we evaluated HER-2/neu over-
expression and amplification in 227 curatively resected
gastric cancers using the new criteria. We performed IHC
and FISH on all the samples and found that all the cases
of 3+ showed amplification, 4 of 11 cases of 2+ showed
amplification, but all the cases of 0+ and 1+ exhibited no
amplification. Because there was no amplification in IHC
0+ and 1+, the cases of tumors with HER-2/neu amplifica-
tion equals the cases of tumors with overexpression in the
present study.
In the literature, there are conflicting reports about the
correlation between IHC and amplification. For example,
Kim et al. [18] reported that (4%) of 101 cases scored 1+
had amplification measured by FISH, but Bang et al. [4]
reported in the multicenter ToGA trial that the propor-
tion of IHC 0/1+ samples tested positive by FISH in 594
patients was 23%. In our study, we did not find any ampli-
fication sign in IHC 0/1+. We think this discrepancy is
likely due to sample sizes and ethnic groups included in
the reported studies, but other mechanisms may also
contribute the discrepancy, such as polysomy 17 chromo-
some, altered length in the 50-untranslated region of
mRNA of HER-2/neu, some post-transcriptional events,
or the HER-2/neu false positivity of the tumors [19,20].
In our study, the rate of HER-2/neu overexpression/
amplification was 11.89%, which fell within the range of
9.3% to 22.6% [12,13,15,18,21-23] reported after 2005
using the old scoring system. It was also in the range of
Table 3 Univariate and multivariate overall survival
analysis for 227 patients with gastric cancer
Variables Univariate Multivariate
5-year survival rate PHazard ratio P
Age 0.773
≥65 years 39.3
<65 years 41.9
Sex 0.230
male 43.3
female 34.3
Lauren <0.001 0.006
intestinal 48.6 1
diffuse 18.4 1.467
mixed 38.2 1.201
WHO
classification
0.001 0.003
W/D 63.6
M/D 45.1
P/D 24.7
Tumor size 0.001
≥5 cm 21.1 1.395 0.005
<5 cm 53.9 1
Tumor location 0.368 0.647
cardia 40.3
corpus 35.9
antrum 50.0
Invasion depth <0.001 0.604
T1 85.0
T2 66.7
T3 29.8
Lymph node <0.001 <0.001
present 25.4
absent 64.0
TNM stage 0.007 <0.001
I 76.1 1
II 51.7 1.364
III 22.0 1.571
Vessel invasion 0.001 0.016
present 15.0 1.916
absent 43.0 1
Borrmann 0.471 0.221
I 73.3
II 39.5
III 32.9
IV 0
Table 3 Univariate and multivariate overall survival
analysis for 227 patients with gastric cancer (Continued)
HER-2
overexpression
0.351
positive 27.3 0.031
negative 42.8
M/D: moderately differentiated; P/D: poorly differentiated; W/D: well
differentiated.
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6% to 12% given by Hsu et al. using the new scoring
system [24]; these authors were the first to use the new
scoring system in a large-scale experiment, with a
reported rate of 6.1% for HER-2/neu overexpression.
The authors attributed their observed low positivity to
the new criteria and some other reasons, such as geo-
graphic variations, tumor heterogeneity, the employment
of different antibodies, and inter-observer variation.
However, one important reason must be considered for
the variation in the overexpression, which is what Chung
et al. [25] found in their screening program for the
ToGA: HER-2 positivity rates differed by tumor loca-
tions and types, for example, rates were higher in the
gastroesophageal junction than in stomach cancer and
higher in intestinal than in diffuse or mixed cancer. In
the patient group studied by Hsu et al., 16.4% of patients
had a tumor of the gastroesophageal junction and 79.8%
patients had stomach cancer, but 50.2% had the intes-
tinal type and 49.8% had a mixed and diffused type,
which we think was the direct reason for his low positi-
vity rate of 6.1%. The situation was the opposite for
Hofman et al. [17], who had 71.5% of patients with
intestinal type and 28.5% with mixed and diffused type,
with a combined HER-2/neu positivity rate of 13.6%. We
had a relatively higher proportion of patients with
gastroesophageal junction and intestinal type cancer in
our patient groups; we thus had a relatively higher
proportion of HER-2 positivity rates.
In our study, we found that HER-2/neu overexpression/
amplification was associated with Lauren type, WHO
histological grade, tumor size and lymph node metastasis.
For the association of the HER-2/neu overexpression/
amplification with clinicopathological findings, most pre-
vious studies reported a higher HER-2/neu overexpres-
sion/amplification in intestinal than in diffuse cancers. For
example, both Tanner et al. [12] and Barros-Silva et al.
[13] reported similar findings. The ToGA [4] study further
confirmed the results by screening a much larger sample
size. To date, it is not clear why HER-2/neu is so closely
associated with intestinal cancer, but a great number of
molecular differences by cancer histology have been
reported. For example, E-cadherin was reported to be
dominantly confined to the diffuse cancer [26,27]. Intes-
tinal cancer is usually well differentiated, but diffuse
cancer is poorly differentiated, which means that overex-
pression/amplification of HER-2/neu are consistent with
WHO classification and Lauren classification. Yonemura
et al. [28] reported that overexpression of HER-2/neu was
related to tumor size, invasion depth, lymph node metas-
tasis and TNM stage, whereas Mizutani et al. [29] found
that overexpression of HER-2/neu was associated with
invasion depth and liver metastasis but not with lymph
node metastasis. We believe that the most important
reason for differences may be the use of different stan-
dards to enroll patients, in addition to selection of tissue
samples and the criteria for IHC scoring.
To minimize the impact of staging factor on prognosis
analysis, we used patients with curatively resected gastric
cancer. In our univariate analysis, overexpression or amp-
lification of HER-2/neu was a prognostic factor but the
statistical result for such an association was not present in
multivariate Cox proportional hazards model with adjust-
ment of age and sex. In a summary of reported studies on
HER-2/neu prognosis after 2005, as shown in Table 4,
Park et al. [15] also used patients with curatively resected
gastric cancer and adopted the old standard and reached
the same conclusion as ours after similar analyses, in
which they found HER-2/neu to be a prognostic factor in
the univariate analysis but not in the Cox proportional
hazards model. Later, Hsu et al. [24] employed the new
standard but failed to yield any positive results. Similarly,
Begnami et al. [22] also found HER-2/neu amplification to
be an independent prognostic factor in univariate log-rank
analysis but not in a Cox proportional hazards model.
By contrast, Liu et al. [23] showed that the overexpres-
sion of HER-2 predicted poor prognosis in patients with
Table 4 Literature review about the prognosis of HER-2 overexpression or amplification in gastric cancer
Reference N (total/survival analysis) % HER-2/neu+ definition Prognostic factor
Univariate analysis/association Multivariate analysis
[12] 131/131 12.2 (FISH+) Yes/two groups Not done
[15] 182/182 15.9 (IHC 2+ or 3+) Yes/two groups No
Kim MA
(2007) [ 18]
248/96 7.7 (FISH+) Yes/Intestinal type, I stage Not done
[13] 463/256 9.3 (FISH+) Yes/Expansive type Not done
[21] 1414/582 (section), 598/255 (TMA) 12.3 (section), 17 (TMA)
(IHC 2+ or 3+)
Yes/Differentiation (W+M) No (section)/Yes
(TMA)
[22] 221/221 15 (FISH+) Yes/two groups Not done
[23] 217/217 11 (IHC 3+ ) Yes/two groups and intestinal type Not done
[24] 1036/1036 6.1 (IHC3+ or IHC2+ and FISH+) No No
FISH: fluorescence in situ hybridization; IHC: immunohistochemistry; M: moderately differentiated; TMA: tissue microarray; W: well differentiated.
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gastric cancers, but the authors defined IHC 3+ as
overexpression and neglected IHC 2+ in their statistical
analysis. Worth a mention was that Barros-Silva et al.
[13], MA Kim et al. [18] and KC Kim et al. [21] all
reached a positive conclusion in their subgroup analysis,
especially for the study by MC Kim. They did a subgroup
OS analysis in differentiated gastric cancer (well- and
moderately differentiated) with the largest sample to date
(1,414 patients) and found in the Cox model that Her-2/
neu overexpression was a prognostic factor, which perhaps
gave us a new perspective to look at Her-2/neu overex-
pression in gastric cancer. In a time of targeted therapy,
how to identify the right target and administrate the right
drug to the right patients is a great challenge for both
doctors and patients. The ToGA trial led to the conclusion
that trastuzumab should be used to treat patients with
Her-2/neu overexpression, but according to the above
data and analyses, we wonder whether further large
studies should be done to refine the right patients for the
use of trastuzumab, a drug that is too expensive for every
patient to afford in China.
The limitation of this study was the use of microscopy
arrays that limited the assessment of HER-2/neu over-
expression/amplification to very small portions of the
tumor. Although Marx et al. [30] reached the conclusion
that HER-2 amplification was highly homogenous in gas-
tric cancer, and even a whole-tissue section cannot be
guaranteed to contain all the HER-2/neu overexpres-
sion/amplification, it is a fact that intratumoral hetero-
geneity for HER-2/neu overexpression/amplification was
found to be more common in gastric cancer than in
breast cancer. Thus, our study may underestimate the
overall positivity of HER-2/neu overexpression/amplifi-
cation in gastric cancer.
Conclusions
We conclud that HER-2/neu overexpression/amplification
was present in 11.89% of Chinese patients with gastric
cancer, and is not an independent prognostic factor for
patients with curatively resected gastric cancer.
Abbreviations
FISH: Fluorescence in situ hybridization; H & E: hematoxylin and eosin;
HER: human epidermal growth factor receptor; IHC: Immunohistochemistry;
TMA: tissue microarray; TNM: Tumor-Node-Metastasis; WHO: World Health
Organization.
Competing interests
The authors declare that they have no competing interests.
Authors’contributions
FZ carried out the experiment and data acquisition, and drafted the
manuscript. NL helped with the experiment and data acquisition. WJ helped
with the literature research. ZH and LX participated in collecting the samples.
QW helped with writing, discussion of and editing the manuscript. LW
designed the study, and read and revised the manuscript. All authors read
and approved the final manuscript.
Acknowledgements
This work was supported by a grant from the Project Sponsored by National
Natural Science Foundation of China (No. 81071667) and a grant from the
Project Sponsored by Science and technology commission of Shanghai
Municipality (No.09DZ1950100). We thank Dr Lei Wang for his technical
assistance.
Author details
1
Department of Oncology, Shanghai First People’s Hospital Affiliated
Shanghai Jiaotong University, Shanghai 200080, China.
2
Cancer Institute of
Yangzhong City, People’s Hospital of Yangzhong City, Jiangsu Province
212200, China.
3
Department of Pathology, People’s Hospital of Yangzhong
City, Jiangsu Province 212200, China.
4
Department of Epidemiology,
University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Received: 26 August 2012 Accepted: 26 November 2012
Published: 18 December 2012
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doi:10.1186/1477-7819-10-274
Cite this article as: Zhou et al.:Prognosis significance of HER-2/neu
overexpression/amplification in Chinese patients with curatively
resected gastric cancer after the ToGA clinical trial. World Journal of
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