Durham, N.C. - Stdies show that women who use oral contraceptives for three or more years reduce their risk of ovarian cancer by up to 50 percent. Most experts believe suppressing ovulation causes the reduction in cancer risk.

Now, researchers at the Duke University Comprehensive Cancer Center have taken a closer look at a hormone contained in birth control pills. Associate professor Joellen Schildkraut and her colleagues in the Department of Community and Family Medicine compared the effects of high and low levels of progestin. They found that the higher the dose of progestin, the lower the risk of ovarian cancer. Schildkraut says, with ovarian cancer, prevention is critical.

"What happens with ovarian cancer - it's rare compared to breast cancer and colon cancer - is that it's usually detected at a late stage, when not a lot can be done in terms of treatment of the disease."

Schildkraut cautions that more studies are needed, and that high doses of the hormone are associated with increased breast cancer and heart disease risk.

I'm Tania Zeigler for MedMinute