Association between body mass index and breast cancer risk: evidence based on a dose–response meta-analysis

In summary, this dose-response meta-analysis of prospective cohort studies showed that every 5 kg/m² increase in BMI corresponded to a 2% increase in breast cancer risk in women. However, higher BMI could be a protective factor in breast cancer risk for premenopausal women. Further studies are necessary to verify these findings and elucidate the pathogenic mechanisms.