SAN ANTONIO, Sept. 7 (UPI) -- Preventative mastectomies do reduce cancer risks for some women, U.S. researchers say.

Researchers at the University of Texas Health Science Center at San Antonio say for some women with specific genetic mutations preventative mastectomies and removal of the fallopian tubes and ovaries can be worth it because their risks of breast and ovarian cancer are significantly reduced.

"We have believed this for 15 years but it's been so controversial -- removing organs for cancer risk," Dr. Gail Tomlinson, one of the researchers, said in a statement. "The idea can be jarring unless one considers that the women with the specific genetic mutations, BRCA1 and BRCA2, are seeing people in their family suffering from these cancers one after another."

The researchers, whose results were published in the Journal of the American Medical Association, studied 2,500 women at genetic risk at 22 centers in Europe and North America.

They found no breast cancers were diagnosed in the 247 women who chose preventive mastectomies. However, one in 13 of the 1,372 who did not have the surgery were diagnosed with breast cancer.

Women who had their ovaries and fallopian tubes removed had a lower risk of ovarian cancer, including those with prior breast cancer, and a lower risk of dying from either cancer, the researchers say.