Cushioning the blow.

It’s no fun to realize it’s already the middle of summer and you still don’t the beach bod you’d hoped for. So we’re bringing you a silver lining, particularly if you’re a premenopausal woman. A massive pooled analysis on prospective cohorts of premenopausal women spanning four continents (n>750K) evaluated the association between BMI and breast cancer risk. Paradoxically, the younger the age, the more protective high BMIs were against breast cancer. This is in stark contrast to the exact opposite among postmenopausal women. High BMI was protective across all age groups, but was associated with a >4-fold(!) decrease in breast cancer incidence among the youngest women analyzed. The hypothesis is, compared with postmenopausal, premenopausal obesity is most likely a surrogate for increased childhood adiposity known to cause high estrogen levels that may induce early tumor suppressor genes. TBL: The authors “do not advocate weight gain as a preventative measure against premenopausal breast cancer,” but it’s not a bad silver lining to those extra pounds early in life. | Schoemaker, JAMA Oncol 2018