CCNB2 expression correlates with worse outcomes in breast cancer patients: a pooled analysis

Cyclin B2 (CCNB2) is upregulated in Breast Cancer (BC) and associated with worse relapse-free survival (RFS). However, its correlation with other clinical outcomes in BC was yet to be clarified. Therefore, this study aimed to explore the clinical significance of CCNB2 in BC. A comprehensive search was performed in PrognoScan and Gene Expression Omnibus (GEO) databases by searching the keywords of CCNB2 and breast cancer. Pooled hazard ratios (HRs) of overall survival (OS), relapse-free survival (RFS), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and disease-free survival (DFS), and their corresponding 95 percent confidence intervals (CI) were calculated. Sensitivity analysis by omitting one study at a time and publication bias assessment by Egger's test and Begg's test were conducted. The clinical outcomes were externally verified via Kaplan-Meier Plotter. All of the statistical analyses were performed through STATA 17.0, and P values of less than 0.05 were taken to be statistically significant. Seven records with 1,074 participants were included for OS, with HR of 1.71 (95 percent CI = 1.24-2.35). Verification through Kaplan-Meier Plotter online tool based on 1,897 patients showed an HR of 1.75 (95 percent CI = 1.45-2.12, P < .01). For RFS, 11 records with 1,253 participants were included with the pooled HR of 1.37 (95 percent CI: 1.10-1.71). Verification based on 4,929 patients found and HR of 1.97 (95 percent CI = 1.78-2.19, P < .01). Regarding DMFS, the pooled HR of 10 records with 1,395 participants was 1.60 (95 percent CI: 1.24-2.05) and verification based on 2,765 patients revealed an HR of 1.97 (95 percent CI = 1.68-2.31, P < .01). For DSS, four records with 689 participants were included for DSS, with HR of 1.38 (95 percent CI = 0.59-3.24). The HR of DFS was 1.60 (95 percent CI: 0.46-5.51) after pooling 3 records with 379 participants. High expression of CCNB2 in BC is associated with worse OS, RFS, and DMFS, but not with DSS and DFS. More well-designed studies from different populations and different BC types are still needed.