Lack of association between bcl-2 expression and prognosis of osteosarcoma: a meta-analysis

Several studies investigated the bcl-2 in prognosis of osteosarcoma, but no consistent conclusions were achieved. This meta-analysis was conducted to determine the prognostic role of bcl-2 in osteosarcoma. Databases including Pubmed, Embase, Cochrane library, Google scholar, Wanfang and CNKI were searched systematically up to March 1, 2014. Cohort studies assessing the prognostic role of bcl-2 expression in patients with osteosarcoma were included. Pooled odds ratio (OR) with 95% confidence intervals (95% CI) was adopted. Sensitivity analysis was also performed. Five studies with a total of 202 patients were included in final analysis. Compared with positive bcl-2 expression, negative bcl-2 expression was associated with better 3-year overall survival (OR=0.21, 95% CI 0.07-0.65, P=0.007). No significant difference was achieved with respect to 5-year overall survival (OR=0.76, 95% CI 0.42-1.38, P=0.264) and diseases-free survival (OR=1.20, 95% CI 0.47-3.06, P=0.709). Sensitivity analysis indicates the conclusion was stable. This meta-analysis suggests that the bcl-2 expression may be independent with the prognosis for patients with osteosarcoma. Nevertheless, additional well-designed studies with larger sample size are needed to further confirm the results.