The association between polycystic ovary syndrome and breast cancer: a meta-analysis

OBJECTIVE: The results of epidemiological studies investigated the association between polycystic ovary syndrome (PCOS) and the breast cancer are inconsistent. This meta-analysis was conducted to estimate the association between PCOS and the breast cancer risk. We searched PubMed, Web of Science, and Scopus for observational studies until June 2015. Data were independently extracted and analyzed using 95% odds ratio, and confidence intervals (CIs) based on the random-effects models. METHODS: We identified 970 references and conducted eight studies with 45,470 participants and 243,064 person- year. RESULTS: The association between PCOS and the breast cancer risk in case-control studies 0.87 (95% CI, 0.44 to 1.31) and that of cohort studies was estimated 1.18 (95% CI, 0.93 to 1.43). CONCLUSION: This meta-analysis demonstrated that PCOS no does increase the risk of breast cancer. Further prospective cohort studies are needed to provide convincing evidence in order to PCOS can increase or not effect on the risk of the breast cancer.