Breast Implants and the Risk of Breast Cancer: A Meta-Analysis of Cohort Studies

Background: The popularity of cosmetic breast augmentation and the incidence of breast cancer have been increasing worldwide. It has been hypothesized that the risk of breast cancer may be greater among patients who have undergone cosmetic breast implantation. Objectives: The authors performed a meta-analysis of the available literature on the risk of breast cancer among women with cosmetic breast implants. Methods: The study was designed as a meta-analysis of observational studies. A systematic search of the English literature (published by August 28, 2013) was conducted in PubMed and EMBASE. Eligible reports were those that included relative risk (RR; the increased or decreased risk of breast cancer associated with breast implants) or the standardized incidence ratio (SIR) of the observed number of cases of breast cancer to the expected number of cases among patients that previously underwent cosmetic breast augmentation. Results: Seventeen studies representing 7 cohorts were selected. Some of these were follow-up reports of previously published studies; in such cases, only the most recent reports were included in the meta-analysis. Summary SIR and RR rates and the corresponding 95% confidence intervals (CIs) were calculated with a random-effects (SIR) or fixed-effects (RR) model. The overall SIR estimate was 0.69 (95% CI, 0.56-0.85), and the overall RR, based on 4 studies, was 0.63 (95% CI, 0.56-0.71). Conclusions: Finding of this meta-analysis suggest that women who have undergone cosmetic breast implantation do not have an increased risk of breast cancer.