Research

Hormonal

Obesity increases the risk of estrogen-receptor-positive (ER+) breast cancer in postmenopausal women through the 'obesity-inflammation-aromatase axis,' where visceral fat produces estrogen via the enzyme aromatase.

For postmenopausal women, carrying extra weight around the middle is dangerous because fat cells act like small hormone factories. They convert other hormones into estrogen, which fuels the growth of many breast cancers. Losing weight reduces this local estrogen production and the inflammation that drives it, directly lowering your risk of developing estrogen-positive breast cancer.

StrongSupportsVERY_HIGH confidence
The positive association of postmenopausal BC risk and specifically estrogen receptor (ER)-positive BC, is presumably due largely to accumulation of estrogen in the adipose tissue of the breast and other tissues. ... This 'obesity-inflammation-aromatase axis' has been proposed to play an important role in increased risk of ER+ breast cancer in postmenopausal women, by elevating estrogen levels in the breasts of women in whom levels of estrogen in the general circulation are reduced (60, 64, 65).
Tanya Agurs‐Collins et al. · Frontiers in Oncology · 2019

Why this rating

Supported by multiple mechanistic studies, prospective cohorts, and consistent findings across the literature.

Source

The Many Faces of Obesity and Its Influence on Breast Cancer Risk

Tanya Agurs‐Collins et al. · Frontiers in Oncology · 2019

DOI 10.3389/fonc.2019.00765

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DOI resolved against Crossref · corpus check 2026-06-10

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