Khincha PP, et al. - Given that early-onset breast cancer is the cancer most often seen in women with Li–Fraumeni syndrome (LFS), a rare autosomal dominant cancer predisposition syndrome with extremely high lifetime cancer risks caused mainly by germline TP53 variants, researchers examined if reproductive factors influence the risk of breast cancer in LFS. From the National Cancer Institute's LFS study, they collected questionnaire data for 152 women with confirmed germline TP53 variants; breast cancer, confirmed by pathology/medical reports, was identified in 85 of these. This first study of reproductive factors and breast cancer in women with LFS suggested the protective effects of breastfeeding against breast cancer risk, especially after at least 7 months of lifetime breastfeeding. They noted a slight increase breast cancer risk in correlation to older age at first live birth.