The news comes from scientists at New York's Memorial Sloan-Kettering Cancer Center. Their findings appear in the Journal of the National Cancer Institute.
Breast cancer is the No. 2 cause of cancer deaths for women. Ovarian cancer holds fourth place, according to the American Cancer Society. Ovarian cancer is also the leading cause of gynecological cancer deaths.
Noah Kauff, MD, and colleagues studied nearly 200 families with a history of hereditary breast cancer.
The women in the study didn't have BRCA1 or BRCA2 gene mutations. Those mutations make it much more likely that a woman will develop breast or ovarian cancer.
The women were about 51 years old when the study started.
The researchers show that for 2,500 women followed for one year, 19 new cases of breast cancer would be diagnosed. Six cases would be expected for women without a family history of breast cancer, the study shows.
However, only one case of ovarian cancer was diagnosed. That's in line with predictions for women of average risk, the researchers note.
The results show that women with a history of hereditary breast cancer -- but without BRCA1 or BRCA2 gene mutations -- "are not at increased risk for ovarian cancer," write Kauff and colleagues.
Other genes may affect breast and ovarian cancer risk, so women should tend to their health regardless of their family history of cancer or their gene status.
Mammograms can help detect breast cancer, but ovarian cancer is often tougher to find at an early stage. Researchers are working on a blood test for ovarian cancer.
A woman's best approach may be to make healthy habits a priority, get an annual pelvic exam, follow other cancer screening guidelines, and tell her doctor about her family's medical history and any problems or concerns that come up.