July 22, 2010 -- A newly identified genetic marker may help predict ovarian cancer risk, Yale University researchers report online in Cancer Research. Variations in the KRAS gene occur in one-quarter of women with ovarian cancer, and 61% of women with ovarian cancer who have a family history of breast and ovarian cancer.
"For many women out there with a strong family history of ovarian cancer who previously have had no identified genetic cause for their family's disease, this might be it for them," says study researcher Joanne B. Weidhaas, MD, PhD, an associate professor of therapeutic radiology and researcher for the Yale Cancer Center in New Haven, Conn., in a news release. "Our findings support that the KRAS-variant is a new genetic marker of ovarian cancer risk."
While BRCA1 and BRCA2 genes are known markers for breast and ovarian cancer risk, only half of the women with a family history of these cancers tested positive for these genes. Fully 60% of these women did test positive for the KRAS genetic mutation, the new study shows.
Women with BRCA genetic mutations tend to develop ovarian cancer at younger ages, but those with the new genetic marker tend to develop ovarian cancer after menopause, the researchers report.
Ovarian Cancer Screening Test Needed
Ovarian cancer is known as a particularly lethal cancer because symptoms can be vague and many women are not diagnosed until the cancer has already started to spread.
"People are blindsided when they get ovarian cancer; they really had no idea," Weidhaas tells WebMD. "This is a cancer where there are not a lot of known risks so there is probably more of an inherited component and it's really important to identify ways for us to know who is really at risk."
What's more, the new KRAS mutation "might predict ovarian cancer in the general population as well," she says. "This will require a large study and needs additional validation."
"Our hope is that in the future, we can combine this test with other blood tests to get a better handle on a woman's risk for developing ovarian cancer," she says. "That is the future." CA-125, for example, is a protein found in the blood of many women with ovarian cancer and could be included in this new screening test.
Yale Cancer Center is now offering genetic testing for the KRAS mutation to women with ovarian cancer and those who are at high risk. MiraDx, a New Haven, Conn.-based biotech company, developed the new test. Weidhaas and a colleague have financial interest in this company.