New Genetic Marker Predicts Ovarian Cancer Risk

A variant of an oncogene is present in a number of women with ovarian cancer and those patients with a family history of breast and ovarian cancer.

Ovarian cancer (OC) is the single most deadly form of women's cancer, typically presenting as an advanced disease at diagnosis in part due to a lack of known risk factors or genetic markers of risk.

In a study performed at Yale University, (New Haven, CT, USA), samples were examined from 157 OC patients. DNA was extracted from fresh frozen tissue, formalin fixed paraffin-embedded tissue, blood, and saliva. The oncogene KRAS-variant was assayed using an allele specific primer and a polymerase chain reaction (PCR)-Taq Man standard assay.

The variant of the KRAS oncogene was present in 25% of all ovarian cancer patients and this variant was found in 61% of ovarian cancer patients with a family history of breast and ovarian cancer. Six out of 10 women without other known genetic markers of ovarian cancer risk had the KRAS-variant. Unlike women with BRCA mutations who develop ovarian cancer at a younger age, women with the KRAS-variant tend to develop cancer after menopause. Because ovarian cancer is difficult to diagnose and thus usually found at advanced stages, finding new markers of increased ovarian cancer risk is critical.

Joanne B. Weidhaas, M.D., Ph.D., coauthor of the study, said, "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. Our findings support that the KRAS-variant is a new genetic marker of ovarian cancer risk.” The findings of the study were published in the July 2010 edition of Cancer Research.

Genetic tests for the KRAS-variant are currently being offered to ovarian cancer patients and to women with a family history of ovarian cancer by MiraDX, (New Haven, CT, USA), a biotechnology company that has licensed the Yale discoveries.

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Yale University
MiraDX