Prognostic significance of Epstein-Barr virus infection in gastric cancer: a meta-analysis.
BACKGROUND
The prognostic significance of Epstein-Barr virus (EBV) infection in gastric cancer (GC) remains unclear. Recently, a number of studies have investigated the association between EBV infection and the prognosis of GC with controversial results. We therefore conducted a meta-analysis to assess its prognostic significance.


METHODS
PubMed and EMBASE were searched for studies up to October 1, 2014. We investigated the association between EBV infection with survival in patients with GC. The pooled hazard ratio (HR) and its 95% confidence interval (CI) were calculated to evaluate risk.


RESULTS
A final analysis of 8,336 patients with GC from 24 studies was performed. Our analysis results indicated that the pooled HR was 0.67 (95% CI: 0.55-0.79; Z = 11.18, P < 0.001). Subgroup analyses stratified by region revealed that the protective role of EBV infection only remained in the Asian population (HR: 0.62, 95% CI: 0.48-0.75; P < 0.001). When stratified by study quality and statistical methodology, the protective role could also be identified in high quality studies (HR: 0.67, 95% CI: 0.55-0.79) and in univariate analysis studies (HR: 0.62, 95% CI: 0.50-0.74). There was no evidence of significant heterogeneity and publication bias.


CONCLUSIONS
The presence of EBV has a favorable impact on GC patient's survival, especially in an Asian population. Future updated studies, especially large-scale randomized controlled studies stratified by region, are warranted as validation studies.
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. liuxch@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. liuxch@sysucc.org.cn.
Xuechao
X
Liu
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. liujj@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. liujj@sysucc.org.cn.
Jianjun
J
Liu
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. qiuhb@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. qiuhb@sysucc.org.cn.
Haibo
H
Qiu
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. kongpf@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. kongpf@sysucc.org.cn.
Pengfei
P
Kong
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. chenshx@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. chenshx@sysucc.org.cn.
Shangxiang
S
Chen
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. liw@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. liw@sysucc.org.cn.
Wei
W
Li
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. zhanyq@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. zhanyq@sysucc.org.cn.
Youqing
Y
Zhan
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. liyf@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. liyf@sysucc.org.cn.
Yuanfang
Y
Li
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. chenyb@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. chenyb@sysucc.org.cn.
Yingbo
Y
Chen
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. zhouzhw@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. zhouzhw@sysucc.org.cn.
Zhiwei
Z
Zhou
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. xudzh@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. xudzh@sysucc.org.cn.
Dazhi
D
Xu
State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China. sunxw@sysucc.org.cn.|Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center, 651# East Dongfeng Road, Guangzhou, 510000, Guangdong Province, China. sunxw@sysucc.org.cn.
Xiaowei
X
Sun
D000569:Americas / Q000453:epidemiology; D001208:Asia / Q000453:epidemiology; D020031:Epstein-Barr Virus Infections / Q000150:complications* / Q000401:mortality; D005060:Europe / Q000453:epidemiology; D006801:Humans; D011379:Prognosis; D016016:Proportional Hazards Models; D013274:Stomach Neoplasms / Q000401:mortality / Q000821:virology*; D016019:Survival Analysis