Combining CA-125 with a new symptom index may improve ovarian CA detection.

A composite tool consisting of a symptom index and the CA-125 blood test identified more than 80% of women with early-stage ovarian cancer and may be useful as part of a multi-step screening process for the disease, according to study findings published online June 25 in Cancer.

M. Robyn Andersen, PhD, of the Fred Hutchinson Cancer Research Center in Seattle, and colleagues conducted a prospective, case-control study involving 75 women with ovarian cancer and 254 healthy women at high risk for ovarian cancer because of familial history. They asked participants to respond to an index consisting of four questions based on common symptoms reported by women with ovarian cancer.

The symptom index was an independent predictor of ovarian cancer, the researchers found, identifying cancer in 50% of those who had cancer but a negative CA-125. The combined tests showed superior sensitivity to ovarian cancer than CA-125 alone and identified 89.3% of women with the disease, and 95.1% of those with late-stage disease. However, this increase in sensitivity comes at a cost of lower specificity.

“A composite marker such as this could serve as a first screen in a multi-step screening program in which false-positive findings are identified via transvaginal sonography before referral for surgery, leading to an adequate positive predictive value for the multistep program,” the researchers conclude.

Andersen MR, Goff BA, Lowe KA, et al. Combining a symptoms index with CA 125 to improve detection of ovarian cancer. Cancer. 2008;113:484-489.