Dr. Michael F. Leitzmann of the National Cancer Institute and colleagues studied 94,525 U.S. women ages 50 to 71 over seven years. The researchers documented 303 ovarian cancer cases during this time and noted that among women who had never taken hormones after menopause, obesity was associated with an almost 80 percent higher risk of ovarian cancer.

In contrast, no link between body weight and ovarian cancer was evident for women who had ever used menopausal hormone therapy, Leitzmann said.

Leitzmann said the findings support the hypothesis that obesity may enhance ovarian cancer risk in part through its hormonal effects. Excess body mass in postmenopausal women leads to an increased production of estrogen, which in turn may stimulate the growth of ovarian cells and play a role in the development of ovarian cancer, Leitzmann explained.

The study is scheduled to be published in the Feb. 15 issue of Cancer.