Hormone Drugs for Women Halve Risk of Colon Cancer, Study Says

Women using estrogen replacement drugs after menopause reduce their risk of colon cancer by about half, researchers say. The finding adds to a growing list of effects, good and bad, from hormone therapy.

“This is a very important benefit from the use of hormone replacement therapy,” said Polly A. Newcomb of the University of Wisconsin in Madison. “This a big reduction in a disease that is the third most common cancer among women.”

Since colon cancer is diagnosed in about 70,000 women annually and about 30,000 die of the disease, the findings suggest that hormone replacement could have a significant public health effect, Newcomb said.

Newcomb and Barry E. Storer, also of Wisconsin, are co-authors of a study to be published today in the Journal of the National Cancer Institute.

In the study, the scientists examined risk factors associated with about 700 women with colon cancer and 1,600 women who were cancer-free.

Adjusting for smoking, age and alcohol use, Newcomb said, the study found that use of estrogen drugs among post-menopausal women caused a 46% reduction in bowel cancer risk. The study, however, found that the hormone replacement had no effect on the incidence of rectal cancer.

However, there is a controversy about the effect of the hormone therapy on breast cancer. A study published in June found a 46% increase in the risk of breast cancer, while another study published last week found no increased risk of breast cancer.