Women with the highest risk of receptor-negative breast cancers, such as African-American women and CRCA1 carriers, can potentially benefit from breastfeeding, according to a meta-analysis of 36,881 breast cancer cases that showed a protective effect of ever breastfeeding against hormone receptor-negative breast cancers. This large cohort study found:
• There were no significant associations between breastfeeding and estrogen receptor (ER)+/progesterone receptor (PR)+ and/or PR+ breast cancers.
• Risk estimates for the association between ever vs never breastfeeding and the breast cancers negative for both ER and PR were similar in 3 cohort and 3 case-control studies.
• Ever breastfeeding showed a stronger inverse association with triple-negative breast cancer (OR=0.78) among parous women.
Citation: Islami F, Liu Y, Jemal A, et al. Breastfeeding and breast cancer risk by receptor status – a systematic review and meta-analysis. [Published online ahead of print October 26, 2015]. Ann Oncol. doi: 10.1093/annonc/mdv379.