The protein CA-125 has long been recognized for predicting ovarian cancer recurrence. According to researchers at The University of Texas MD Anderson Cancer Center, it now shows promise as a screening tool for early-stage disease, if changes in blood levels are evaluated over time. Their findings were recently published in the journal Cancer. If a larger study shows survival benefit, a simple blood test could offer a screening tool to detect ovarian cancer in its early stages in post-menopausal women.
For the prospective, single-arm 11-year study, 4,051 women were enrolled from seven sites across the country. All were healthy, post-menopausal women, ages 50 to 74, who had no strong family history of breast or ovarian cancer. Each woman received a baseline CA-125 blood-test. Using the Risk of Ovarian Cancer Algorithm, a mathematical model based on age and CA-125 score, the women were stratified to one of three risk groups: “Low” came back in a year for a follow-up blood test; “intermediate” were further monitored with a repeat CA-125 blood test in three months; and “high” were referred to receive transvaginal sonography (TVS) and to see a gynecologic oncologist.
Based on the women’s CA-125 change over time, the average annual rate of referral to the intermediate and high groups were 5.8% and 0.9%, respectively. Cumulatively, 117 women (2.9%) were determined to be high risk. Of those women, 10 underwent surgery: four had invasive ovarian cancer; two had borderline disease; one had endometrial cancer, and three had benign ovarian tumors—a positive predictive value of 40%, surpassing the clinical benchmark of 10%.The specificity of the test was 99.9% Researchers note that the four invasive cancers detected were high-grade epithelial tumors, the most aggressive form of the disease, and they were caught at early stages, when the disease is not only treatable, but most often curable. Read the study abstract.
