This is highlighted by cross‐sectional studies showing an increase in metabolic syndrome of postmenopausal BC survivors compared to healthy controls47 and increased visceral adipose tissue due to tamoxifen use.48 Cheney et al49 found that regardless of weight gain or loss, women receiving adjuvant chemotherapy and/or aromatase inhibitors for BC were likely to gain fat mass and lose lean body mass. This evidence concerns the gene CYP19A1 and breast cancer.