Bcl-2 expression and patient survival in gastric cancer: a systematic review of the literature with meta-analysis

The prognostic role of Bcl-2 in gastric cancer remains controversial. We systematically reviewed the evidence for the effect of Bcl-2 expression in gastric cancer to elucidate this issue. PubMed, EMBASE, and Web of Science were searched to identify eligible studies to evaluate the association between Bcl-2 expression and overall survival (OS) and clinicopathological features of gastric cancer. Hazard ratios (HRs) or odds ratios (ORs) with 95 % confidence interval (95 % CI) were pooled to estimate the effect. Bcl-2 expression was not significantly correlated with OS of gastric cancer patients (combined HR 0.88, 95 % CI 0.62-1.25). Subgroup analysis indicated that Bcl-2 expression had a favorable impact on OS in Asian countries (HR 0.60, 95 % CI 0.47-0.77) and cutoff value <15 % (HR 0.69, 95 % CI 0.48-0.97). Furthermore, Bcl-2 expression was significantly associated with TNM stage (OR 0.58, 95 % CI 0.41-0.80), the depth of invasion (OR 0.53, 95 % CI 0.37-0.76), and lymph node metastasis (OR 0.55, 95 % CI 0.42-0.71). Bcl-2 expression predicts less invasion and malignancy in clinicopathological features. Moreover, Bcl-2 could be a favorable prognostic marker for patients of Asian countries.