FRIDAY, Sept. 15 (HealthDay News) -- A key protein may help doctors spot women at hidden risk for developing breast and ovarian cancer, according to new research.

Some women do not have mutations in the BRCA1 or BRCA2 genes for breast and ovarian cancer but still have a strong family history of these cancers.

"We knew that there must have been something else that we could track genetically," principal investigator Tanja Pejovic, an associate professor of obstetrics and gynecology at the Oregon Health & Science University School of Medicine, said in a prepared statement.

In a study appearing in the Sept. 15 issue of Cancer Research, researchers from the Oregon Health & Science University Cancer Institute examined the ovarian tissue of 22 women.

That found that those who had a family history of ovarian cancer but no BRCA mutations had a low level of a protein known as FANCD2, which normally protects DNA and helps repair broken chromosomes. In women with low levels of FANCD2, cells from the ovary were unable to be repaired, putting them at risk of developing cancer-causing mutations.

"Basically we have discovered that by testing ovarian cells for chromosome breakage, we may be able to identify many more women at risk for ovarian and breast cancer than by using BRCA1 and BRCA2 mutation testing," said Pejovic.

She believes these findings may lead a cancer screening method that uses minimally invasive surgery to remove a few epithelial cells from the ovary for testing. During tests, doctors would look for signs of chromosomal breakage.

"Once this method is fully developed," she said, "we will be able to tell a young woman who has a family history of ovarian or breast cancer, but who wants to have children, whether she is at risk or not, without removing her ovary."

More information

The National Cancer Institute has more about breast cancer.