Sex Hormone May Increase Risk of Ovarian Cancer in Obese Women

A sex hormone stimulated by excess body fat may trigger deadly ovarian cancer, a new study found.

Researchers at the National Cancer Institute found that, among women who had never taken hormones after menopause, obesity was associated with an almost 80 percent higher risk of ovarian cancer, the deadliest type of gynecological malignancy. Production of the hormone estrogen linked to excess body mass may stimulate the growth of ovarian cells and play a role in the development of cancer after menopause, the study said.

The findings, published in the Feb. 15 issue of the American Cancer Society’s journal Cancer, adds to evidence about the health risks of obesity, a condition the World Health Organization says affects more than 400 million adults. The Geneva-based agency says overweight and obese people have a greater risk of colon, breast and endometrial cancer.

“These findings support the hypothesis that obesity may enhance ovarian cancer risk in part through its hormonal effects,” the American Cancer Society in Atlanta said in a statement on its Web site. “While studies have linked excess body weight to higher risks of certain cancers, little is known about the relationship between body mass index and ovarian cancer risk.”

Michael F. Leitzmann and colleagues studied 94,525 U.S. women aged 50 to 71 over seven years. The researchers documented 303 ovarian cancer cases during the period. No link between body weight and ovarian cancer was found for women who had used menopausal hormone therapy.

Among women with no family history of ovarian cancer, obesity and increased ovarian cancer risk were also connected in the study. There was no link for women who did have a family history of ovarian cancer.

“The observed relations between obesity and ovarian cancer risk have relevance for public health programs aimed at reducing obesity in the population,” the authors wrote.