Association of Genetic, Environmental and Reproductive Factors with BRCA Mutation Status among Young Breast Cancer Patients: A Multicentre Observational Study from Mumbai

Abstract

Background: The interaction between BRCA mutations and environmental and reproductive risk factors among young Indian breast cancer patients remains insufficiently understood. This study evaluated the association of genetic, environmental, and reproductive factors with BRCA mutation status in young women with breast cancer. Methods: A hospital based analytical cross-sectional study was conducted among 350 breast cancer patients aged <40 years attending tertiary healthcare facilities in Mumbai (June 2025–March 2026). Among 180 women with available BRCA results, 40 (22.2%) were BRCA positive. Genetic association analyses included only patients who underwent BRCA testing. Data were analyzed using IBM SPSS v32. Chi-square tests and logistic regression were performed, with significance set at p<0.05. Results: Among tested patients, family history of breast cancer showed a significant association with BRCA positivity (χ²=14.143, p=0.00017). Women with a positive family history had 4.84-fold higher odds of BRCA positivity (95% CI: 2.03–11.51). No significant associations were observed with age, environmental pollution, radiation exposure, parity, or breastfeeding. Conclusions: Family history remains the strongest predictor of BRCA mutation positivity in young breast cancer patients. Early genetic screening and counseling should be prioritized for high-risk women, while larger multicentre studies are needed to further evaluate environmental and reproductive influences.