Association of body mass index with risk of luminal A but not luminal B estrogen receptor-positive and HER2-negative breast cancer for postmenopausal Japanese women

Background The impact of body mass index (BMI) on the risk of postmenopausal estrogen receptor (ER)-positive breast cancers has been well documented. However, the mechanism for the impact of BMI on the etiology of luminal A and luminal B subtypes has not yet been identified.