The prognostic value of autophagy-related markers beclin-1 and microtubule-associated protein light chain 3B in cancers: a systematic review and meta-analysis

Use of the autophagy-related markers beclin-1 (BECN1) and microtubule-associated protein light chain 3B (LC3B) as prognostic markers has been extensively investigated in various kinds of cancers. However, their prognostic roles are still controversial and not firmly validated. We systematically reviewed the evidence from various studies concerning the relationship between BECN1 and LC3B expression in cancers and overall survival (OS)/disease-free survival (DFS) to elucidate this issue. PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) were searched in July 2013 (then updated in April 2014) to identify eligible cohort studies that reported associations between BECN1 or LC3B expression and OS/DFS in cancer patients. Combined hazard ratios (HRs) with 95 % confidence intervals (95 % CIs) were pooled using fixed-effects or random-effects models according to heterogeneity in different groups. A total of 23 studies in distinct cancers were eligible for systematic review and meta-analysis. Our pooled results identified that a high expression of BECN1 is associated with favorable OS in gastric cancer (HR = 0.49, 95 % CI = 0.34–0.72) and lymphoma (HR = 0.25, 95 % CI = 0.11–0.57), whereas a high expression of LC3B predicts adverse OS in breast cancer (HR = 1.98, 95 % CI = 1.25–3.13). This systematic review and meta-analysis indicated that the autophagy-related marker BECN1 might be a predictive factor of favorable prognosis in gastric cancer, breast cancer, and lymphoma and LC3B might predict unfavorable prognosis of breast cancer. Nevertheless, due to the limited number and retrospective design of the original studies, more powerful prospective cohorts are required to verify these conclusions.