Body Mass Index and Breast Cancer Risk According to Postmenopausal Estrogen-Progestin Use and Hormone Receptor Status

Abstract

To assess the joint relationships among body mass index, menopausal status, and breast cancer according to breast cancer subtype and estrogen-progestin medication use, we conducted a meta-analysis of 89 epidemiologic reports published in English during 1980-2012 identified through a systematic search of bibliographic databases. Pooled analysis yielded a summary risk ratio of 0.78 (95% confidence interval (CI): 0.67, 0.92) for hormone receptor-positive premenopausal breast cancer associated with obesity (body mass index (weight (kg)/height (m)(2)) ≥30 compared with <25). Obesity was associated with a summary risk ratio of 1.39 (95% CI: 1.14, 1.70) for receptor-positive postmenopausal breast cancer. For receptor-negative breast cancer, the summary risk ratios of 1.06 (95% CI: 0.70, 1.60) and 0.98 (95% CI: 0.78, 1.22) associated with obesity were null for both premenopausal and postmenopausal women, respectively. Elevated postmenopausal breast cancer risk ratios associated with obesity were limited to women who never took estrogen-progestin therapy, with risk ratios of 1.42 (95% CI: 1.30, 1.55) among never users and 1.18 (95% CI: 0.98, 1.42) among users; too few studies were available to examine this relationship according to receptor subtype. Future research is needed to confirm whether obesity is unrelated to receptor-negative breast cancer in populations of postmenopausal women with low prevalence of hormone medication use.

Migraine History and Breast Cancer Risk: A Systematic Review and Meta-Analysis

“…This association may be confounded by a factor entitled obesity. Previous epidemiological studies reported that obesity may be more strongly associated with ER+ postmenopausal breast cancer [22]- [26].…”

Obesity and female malignancies

“…A large meta-analysis showed that obesity (BMI 30 kg/m 2 ) is associated with a significantly reduced risk of premenopausal breast cancer (RR 0.83; 95% CI: 0.75e0.91), compared to the risk for normal-weight women. This association seems to apply to receptor-positive breast cancer only, whereas no correlation exists with receptornegative premenopausal breast cancer [13].…”

Morbidity and mortality associated with obesity

“…The association between obesity and breast cancer risk is complex, varying by breast cancer subtype and by menopausal status. Although obesity is associated with reduced breast cancer incidence in premenopausal women (80), it is associated with increased breast cancer incidence in postmenopausal women (80,81). Obesity acts as a protective factor for premenopausal breast cancer, but it is associated with increased risk of breast cancer © Annals of Translational Medicine.…”