Obesity Linked Cancers

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Obesity Linked Cancers

The effect of obesity on breast cancer risk depends on a woman’s menopausal status. Before menopause, obese women have a lower risk of developing breast cancer than do women of a healthy weight. However, after menopause, obese women have 1.5 times the risk of women of a healthy weight .Obese women are also at increased risk of dying from breast cancer after menopause compared with lean women. Obesity seems to increase the risk of breast cancer only among postmenopausal women who do not use menopausal hormones. Among women who use menopausal hormones, there is no significant difference in breast cancer risk between obese women and women of a healthy weight. Both the increased risk of developing breast cancer and dying from it after menopause are believed to be due to increased levels of estrogen in obese women. Before menopause, the ovaries are the primary source of estrogen. However, estrogen is also produced in fat tissue and, after menopause, when the ovaries stop producing hormones, fat tissue becomes the most important estrogen source. Estrogen levels in postmenopausal women are 50 to 100 percent higher among heavy versus lean women. Estrogen-sensitive tissues are therefore exposed to more estrogen stimulation in heavy women, leading to a more rapid growth of estrogen-responsive breast tumors. Another factor related to the higher breast cancer death rates in obese women is that breast cancer is more likely to be detected at a later stage in obese women than in lean women. This is because the detection of a breast tumor is more difficult in obese versus lean women. Weight gain during adulthood has been found to be the most consistent and strongest predictor of breast cancer risk in studies in which it has been examined.

The distribution of body fat may also affect breast cancer risk. Women with a large amount of abdominal fat have a greater breast cancer risk than those whose fat is distributed over the hips, buttocks, and lower extremities.

Best Regards

Laura Gray

Senior Journal Coordinator

Journal of obesity and eating disorders