Park S, et al. – Researchers investigated the influence of parity on the risk of developing a specific subtype of breast cancer and prognosis according to subtypes. Study participants included 158,189 patients of the Korean Breast Cancer Society Registry database who were enrolled from 1996-2015. According to findings, hormone receptor-negative subtypes were more frequently encountered among women who had more than three children. Among patients younger than 50 years of age and among patients with triple-negative breast cancer, women who had more than three children were noted to be associated with worse prognosis.