Combining a symptoms index with CA 125 to improve detection of ovarian cancer

The current study sought to examine whether an index based on the specific pattern of symptoms commonly reported by women with ovarian cancer could be used in combination with CA 125 to improve the sensitivity or specificity of experimental methods of screening for ovarian cancer.

A prospective case-control study design was used. Participants included 254 healthy women at high risk for disease because of family history, and 75 women with ovarian cancer. Logistic regression analysis was used to determine whether the symptom index predicted cancer.

Symptom index information was found to make a significant independent contribution to the prediction of ovarian cancer after controlling for CA 125 levels (P<.05). The combination of CA 125 and the symptom index identified 89.3% of the women with cancer, 80.6% of the early-stage cancers, and 95.1% of the late-stage cancers. The symptom index identified cancer in 50% of the affected women who did not have elevated CA 125 levels. Unfortunately, 11.8% of the high-risk women without cancer also received a positive symptom index score.

The addition of a symptom index to CA 125 created a composite index with a greater sensitivity for the detection of ovarian cancer than CA 125 alone and identified >80% of women with early-stage disease. A composite marker such as this could serve as a first screen in a multistep 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.