Study: Birth Control Pills May Cut Risk of Colorectal Cancer

Women using birth control pills may be up to 20 percent less likely to develop colorectal cancer, according to researchers at the Institute of Pharmacological Research in Milan, Italy.

Researchers are speculating that over the past 20 years, mortality rates for colorectal cancer have dropped more in women than in men due to the birth control pill's hormones.

The researchers reviewed the results from 19 international studies that compared colon cancer rates for women who had taken birth control pills between the mid 1962 and 1980s, according to the study published in the British Journal of Cancer.

"For awhile now we have suspected estrogen in the pill could protect against bowel cancer and our research has gone some way to confirm this," said Dr. Carlo La Vecchia from the Institute. "In the future, it may be possible to develop new treatments that take advantage of the anti-cancer qualities of the pill."

Researchers believe that estrogen blocks the growth of cancer cells in the bowel by reducing the amount of bile acids, which have been linked to colon cancer.

The study indicates that protection against cancer was stronger for women who had stopped taking birth control pills within the last 10 years of the research period, compared to those who had stopped taking the pill earlier.

Previous studies have shown that hormone replacement therapy could protect women from colorectal cancer to the same degree, said the researchers.

The study's relevancy may be compromised by the use of birth control pills of much older formulations than are used today.

Other sources: British Journal of Cancer, Cancer Research Campaign, AP