Weight gain after menopause ups breast cancer risk

NEW YORK, July 12 (Reuters) Women who gain weight after menopause increase their risk of developing invasive breast cancer. Conversely, weight loss reduces the risk, researchers report.

The findings come from an analysis of data from the Nurses Health Study, published in the July 12 issue of the Journal of the American Medical Association.

Dr A Heather Eliassen, from Brigham and Women's Hospital in Boston, and her team point out that many studies have established the relationship between weight gain and increased breast cancer risk. However, the few studies that evaluated the effect of weight change after menopause have yielded conflicting results.

They therefore studied these relationships in a group of 49,514 women between 30 and 55 years old who were premenopausal in 1976, had no history of cancer, and became postmenopausal or underwent removal of both ovaries over the course of the study.

At follow-up in 2002, there were 2376 cases of invasive breast cancer among postmenopausal subjects whose weight had been documented.

Dr Eliassen and her team accounted for other risk factors for breast cancer and found that the risk of developing breast cancer for women who gained 25 kilograms or more since age 18 was 45 per cent higher than for those whose weight remained stable. The risk was increased by 18 per cent for women who gained 10 kg or more after menopause.

Among women who lost at least 10 kg before menopause, the risk dropped 16 per cent, while women who lost at least 10 kg after menopause decreased their risk by 23 per cent. For those who maintained their weight loss after menopause, the risk dropped by 57 per cent.

However, few women lose weight after menopause, the researchers point out. Therefore, ''women should avoid weight gain throughout adult life rather than count on losing weight after menopause,'' Eliassen's group advises, to cut the risk of breast cancer.

Reuters SY VP0940