A new study may let some women with a family history of breast cancer breathe a little easier—it shows they are not at significantly greater risk of also developing ovarian cancer.

For women with a specific mutation (BRCA1 or BRCA2), the risk of developing breast cancer is between nine and 36 times the normal risk of getting the disease. These women also face the additional burden of a higher risk of developing ovarian cancer (between six and 61 times the normal risk). But this group of women makes up only about half of the cases of hereditary breast cancer caused by a single mutation. Until now, for those other women with an unidentified mutation but an obvious hereditary risk–three or more breast cancer cases on the same side of the family, at least one of which occurring before the age of 50–the risk of ovarian cancer hasn't been known. So to be on the safe side, they –like women with the identified BRCA1 and BRCA2 mutations–have been advised to undergo screening and maybe even surgical removal of the ovaries to guard against ovarian cancer.

A group of researchers at Memorial Sloan-Kettering Cancer Center in New York looked at a group of women with a family history of breast cancer (but not ovarian cancer) who had undergone genetic testing for the BRCA mutations. Then they followed up to see if they developed ovarian cancer. The study, published in the current issue of the Journal of the National Cancer Institute, found that the women who did not carry the BRCA mutations didn't develop ovarian cancer at a higher-than-expected rate.

If confirmed by other studies, that suggests that these women don't need to take part in intensive screening programs for ovarian cancer, and can avoid not only the anxiety and expense, but also invasive medical procedures. "That would take surgery off the table," says Noah Kauff, an obstetrician/gynecologist and also a genetics fellow at Sloan-Kettering. (Of course, they are still at higher risk of breast cancer, so they should undergo heightened monitoring for that disease.)

What does this mean for a woman with a strong family history of breast cancer but not of ovarian cancer? "She should be seeking genetic counseling and testing," says Kauff. Not only will this help quantify her breast cancer risk and devise an appropriate monitoring strategy, but it may help her breathe a little easier about another deadly disease. If she doesn't carry a BRCA mutation, it doesn't guarantee she won't ever get ovarian cancer, but her risk is probably not high enough to take part in aggressive screening measures, Kauff says.

Find out more: Go to the U.S. News guide on breast cancer to get in-depth information about symptoms, tests, treatment, and prevention.