HRT May Protect Women From Colon Cancer

ByABC News
April 22, 2009, 2:31 PM

April 23 -- WEDNESDAY, April 22 (HealthDay News) -- Older women using hormone replacement therapy appear to have a 28 percent reduction in their risk of developing colorectal cancer, a new study found.

But researchers don't yet know why the link seems to exist. And the main message to women remains the same: Take hormone replacement therapy at the lowest dose possible for the shortest period of time possible and only for menopausal symptoms such as hot flashes.

"This is not a primary treatment indication for hormone therapy," said Dr. James Liu, chairman of the department of obstetrics and gynecology at University Hospitals MacDonald Women's Hospital in Cleveland. "If a woman happens to be on the therapy [for menopausal symptoms] this could be a benefit but it's not a reason to stay or start the therapy."

The study, by researchers at the Mayo Clinic in Rochester, Minn., was to be presented Wednesday at the annual meeting of the American Association for Cancer Research, in Denver.

This is not the first time researchers have seen an association between hormone replacement therapy (HRT) and a lower risk of colon cancer.

"This just confirms what we knew before," said Dr. Yiwu Huang, associate program director of hematology and medical oncology at Maimonides Cancer Center in New York City.

The link was first picked up in 2002 when the results of the landmark Women's Health Initiative were first announced. That study found a 40 percent reduced colon cancer risk in women taking combined estrogen and progestin. The risk reduction disappeared, however, when women stopped taking their therapy, Liu said.

The authors of the new study looked at more than 37,000 Iowa women, who ranged in age from 55 to 69 at the start of the study in 1986. Participants had completed questionnaires on oral contraceptive and hormone therapy use. The researchers were able to analyze colorectal cancer tissues in 40 percent of the women.

There was no relationship between use of oral contraceptives and colorectal cancer.