Body mass index and breast cancer risk in Japan: a pooled analysis of eight population-based cohort studies

BackgroundA positive association between body mass index (BMI) and breast cancer risk among postmenopausal women has been reported, and a weak inverse association has been suggested among premenopausal women from studies in the Western population. The effects of BMI on breast cancer have remained unclear among the Asian population, especially in premenopausal women.MethodsWe assessed the associations between BMI and breast cancer incidence by a...