Obesity has a demonstrable relationship to increased rates of breast cancer. Although the mechanisms are not fully clear, certain pathways towards improved treatment are suggested.
Obesity, which is especially common in the United States, can promote both the onset and progression of numerous types of cancer, including breast cancer. Both breast cancer and obesity are associated with metabolic and immune dysregulation, and obesity can promote chronic low-grade inflammation in white adipose tissue, driving further dysfunction that can relate to breast cancer onset. This article, published in Cancer and Metastasis, analyzes the intersection of obesity and breast cancer, with an emphasis on shared patterns of immune dysregulation in both of these disease processes.
The authors begin by describing the epidemiological evidence for a link between obesity and breast cancer. Adipose tissue is the predominant site of estrogen production after menopause, and this tissue is increased in obese women. Because obese postmenopausal women, therefore, have elevated levels of estrogen, they are exposed to more of estrogen’s protumorigenic effects. The relationship between breast cancer and obesity relates to subtype and menopausal status, with ER+ increasing the most. The relationship between HER2+ breast cancer and obesity is not yet fully understood.
The authors also describe the metastatic progression of breast cancer in obese women. For all subtypes, women who are obese tend to have larger tumors at diagnosis and an increased risk of lymph node metastases. They note that increased white adipose tissue mass appears to be the nexus of tumor biology and related forms of dysregulation in obesity. Other mechanisms related to adipokines and leptin production are also described.
The authors conclude that obesity promotes the onset and progression of numerous cancers, and poses a significant public health risk. They note that dietary interventions remain highly relevant due to their targeting of metabolic disruptions. Breaking the link between obesity and breast cancer would require treatments that limit the protumor effects of adipose dysregulation.
Reference
Devericks, E. N., Carson, M. S., McCullough, L. E., Coleman, M. F., & Hursting, S. D. (2022). The obesity-breast cancer link: a multidisciplinary perspective. Cancer and Metastasis Reviews, 41(3), 607-625. https://doi.org/10.1007/s10555-022-10043-5
