Just When You Thought You'd Made Up Your Mind About Hormones

What are you more afraid of-the chance of developing colon cancer or the chance of developing breast cancer? Your answer may help you decide whether you should consider HRT.

In medicine, just about any course of treatment involves tradeoffs. The side effects of a certain medication vs the pain relief it might provide, for instance. But with hormone replacement therapy, you need to create an algorithm to calculate your own risk-benefit ratio (and better be ready to adjust it as research continues to mount).

The latest variable in the HRT equation is the protective effect it appears to have against development of colorectal cancer. In a large study, presented at the annual meeting of the American Association for Cancer Research, a team of researchers led by David Limsui, M.D., of the Mayo Clinic, found that women who reported they had used hormone therapy, had a 28 percent lower incidence of colorectal cancer than women who didn't use HRT. "We still don't know how estrogen compounds work in cancer prevention, which is intriguing," says Dr. Limsui.

Dr. Limsui adds that other studies have also found that hormone therapy protects postmenopausal women against colon cancer. The largest randomized clinical trial was the 16,000-participant Women's Health Initiative, which concluded in 2004 that combination hormone therapy (estrogen and progestin) reduced a woman's risk of colorectal cancer by about 40 percent, he says. "But few studies have delved deeper to see how these hormones work at the molecular level," Dr. Limsui says. "Based on our findings, we need to continue exploring the cancer pathways that might be affected by these hormones."

The bottom line: Assess your menopausal symptoms, review your family history and discuss your options with your health care advisor.