Impact of obesity on mammary gland inflammation and local estrogen production.

Obesity rates have risen dramatically over the past century, having nearly doubled since 1980. Changes in diet and lifestyle have contributed to this occurrence in younger women, and changing hormone levels during the menopausal transition has no doubt exacerbated the issue in older women. The relationship between adiposity and breast cancer is clear in postmenopausal women, and is intimately linked to the increased expression of aromatase and the production of estrogens within the breast adipose. This, in turn, is highly dependent on the localized chronic inflammation observed in obese adipose. This review will therefore explore the relationship between obesity, inflammation and estrogens, with a particular focus on the molecular regulation of aromatase in the postmenopausal breast in the context of obesity and breast cancer.