Prognostic Value of Cyclin B1 Expression in Cancers of the Digestive System: A Meta-Analysis

Cyclin B1 is a mitosis-related protein implicated in the progression of various cancers. However, the prognostic value of Cyclin B1 in digestive system cancers remains controversial. We investigated the prognostic value of Cyclin B1 in cancers of the digestive system by using a meta-analysis. Relevant studies published up to May 10, 2015 were identified via PubMed, Embase, Web of science and the Cochrane Library databases. Articles that investigated the prognostic value of Cyclin B1 in patients with pancreatic cancer (PC), esophageal cancer (EC), gastric cancer (GC) or colorectal cancer (CRC) based on immunohistochemistry (IHC) were included. Data on overall survival (hazard ratio [HR] and 95% confidence intervals [CI]) and clinicopathologic features were collected. Ten enrolled studies (1392 patients) were identified. The combined HR and 95% CI suggested overexpression of Cyclin B1 was associated with significantly poorer overall survival (OS) in digestive system cancers. Similar trends were also observed in subgroup analysis based on the type of analysis for OS, origin of cancer, number of patients and publication year. Furthermore, overexpression of Cyclin B1 was associated with significantly poorer OS in PC and EC (tumor type) and Asian patients (ethnicity). Cyclin B1 overexpression was significantly associated with lymphatic invasion, venous invasion, T category, N category and TNM stage, but not histological grade, in EC; similar results were observed for squamous carcinoma. Overexpression of Cyclin B1 was associated with significantly poorer OS in digestive system cancers. Further large-scale prospective studies are required to confirm the value of Cyclin B1 as an independent prognostic biomarker.