Women who pile on the kilos more at risk of breast cancers

May 23 2006

According to a large new study women who pile on the kilos as adults increase their risk of all types of breast cancer even if they do not take hormone replacement therapy after menopause.

The study supports a growing body of evidence which has found that weight and breast cancer are inextricably linked and reveals that the greater the weight gain as an adult, the greater the risk for all histological types, tumor stages, and grades of breast cancer, in particular advanced malignancies.

The study, which is the first to investigate the relationship between weight gain and type of breast cancer, found that the most extremely obese women were up to three times more likely to have regional or distant metastases than women with less weight gain.

The study of more than 44,161 postmenopausal women who were not taking hormone therapy found that the more weight a woman gained, the greater her risk for all types, stages, and grades of breast cancer.

Heather Spencer Feigelson Ph.D., M.P.H of the American Cancer Society and colleagues found that in comparison to women who gained 20 pounds or less during adulthood, women who gained over 60 pounds were almost twice as likely to have ductal type tumors and more than 1.5 times more likely to have lobular type cancers.

The risk for metastatic disease increased for all women who gained weight, with the risk was greater than three-fold for women who gained over 60 pounds.

Heather Spencer Feigelson Ph.D., M.P.H of the American Cancer Society and colleagues found that the weight gain increased the risk of estrogen receptor positive tumors, but not of tumors that did not present estrogen receptors.

Experts believe that breast cancer risk is linked to increased lifetime levels of circulating estrogen and fat tissue increases circulating estrogen resulting in a greater risk.

According to the American Cancer Society breast cancer is the second leading cause of cancer death among U.S. women, after lung cancer, and more than 200,000 people are diagnosed and another 40,000 die from it each year.

Globally more than 1.2 million men and women develop breast cancer every year.

Dr. Feigelson and her team say the findings illustrate the relationship between adult weight gain and breast cancer, and the importance of maintaining a healthy body weight through-out adulthood.

The research is published in the July 1 issue of CANCER.