Obesity and Breast Cancer
Strong Link Between Obesity and Breast Cancer
There is a growing connection between breast cancer and obesity - especially abdominal and upper-body obesity. For example, almost half of all breast cancer cases occur in obese women. Also, cancerous breast tumors are notoriously hard to find in young women with more than 15-20 percent excess body fat. Exactly how severe overeight leads to breast cancers is not yet known. The link between body mass index and breast cancer is mostly statistical. We can see it, but we don't understand exactly why it exists.
Xenestrogens May Be Causal Factor in Breast Cancer Incidence
A possible explanation for the association between obesity and breast cancer is that obese women store xenestrogens in their extra fat cells. Xenestrogens are harmful estrogen-like compounds resulting from environmental pollution.
Weight Control Important During and After Menopause
Because of the link between obesity and breast cancer, it is important for all women to maintain control over their weight, especially as they enter menopause. Cancer Research UK say that post-menopausal women who are overweight have higher levels of estrogen and testosterone and this may double the risks of breast cancer. They urge post-menopausal women to consider losing weight.
Breast Cancer and Obesisty - Studies
A recently published finding from the Nurses' Health Study in Boston found that post-menopausal women just 44 pounds overweight double their risk of breast cancer. Further, "There seems to be even a stronger association with greater degrees of obesity," according to Harvard University endocrinologist JoAnn Manson, M.D., one of the heads of the study.
Other studies have found similar results. The probable explanation, Manson told me, is that after menopause fat becomes the primary source of estrogen in a woman's body swamping outside sources of estrogen (like DDT) that environmentalists have tried to link to the disease.
Meanwhile, a recent Yale study found that severely obese women are more than three times as likely to have their breast tumors detected at a later, less treatable stage of the disease.
Even independent of this, other studies show severe obesity apparently decreases survival rates, perhaps because severe obesity makes a woman much less likely to survive any major surgery.
The Yale study is also merely the latest of several to link severe obesity with late detection of breast tumors. Apparently the excess fat delays detection.
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