We reviewed the evidence for bariatric surgery reducing the risk of breast cancer. Data was extracted from multiple libraries, including PubMed, EMBASE, and Medline, to perform a systematic review. Abstracts were reviewed by two independent reviewers. Thirty-eight full-text articles were identified from 1171 abstracts. Four studies were included for meta-analysis; 114 of 10,533 (1.1%) patients receiving bariatric surgery versus 516 of 20,130 (2.6%) controls developed breast cancer, odds ratio 0.564 (95% CI 0.453 to 0.702) using a fixed effects model (P < 0.001) and odds ratio 0.585 (95% CI 0.247 to 1.386) using a random effects model (P 0.223). Bariatric surgery may reduce the risk of breast cancer. More research is required due to heterogeneity of studies, difficulty in identifying accurate controls, and limited follow-up.
Keywords: Bariatric surgery; Breast cancer; Obesity; Risk reduction; Systematic review; Weight loss.