Women who know they're at high risk for developing ovarian or breast cancer can dramatically lower their risks of developing the diseases if they get their healthy ovaries or breasts surgically removed, new research shows.

The study, which appears in Wednesday's edition of the Journal of the American Medical Association (JAMA), involved BRCA1 and BRCA2, which are human genes, CBS News Medical Correspondent Dr. Jennifer Ashton explained on "The Early Show."

Ashton, a practicing obstetrician/gynecologist, said mutation of those genes has been linked to about 10 percent of hereditary breast and nine percent of hereditary ovarian cancer. Women carrying the mutations have a risk five times greater of getting breast cancer than those who don't, and a risk at least 10 times higher for ovarian cancer.

Researchers followed nearly 2,500 women with BRCA mutations in four countries for an average of four years. At the start, they were all cancer-free, and most were younger than 50.

The study found that women who chose to have their healthy ovaries and fallopian tubes surgically removed not only lowered their risk for ovarian cancer, but breast cancer, as well. Women who underwent prophylactic mastectomy reduced their risk for breast cancer.

The researchers found that the women with the BRCA mutation who had the operations decreased their risk of dying of both types of cancer by 70-to-80 percent.

Read more from CBS News here.