Doctors may be able to use blood tests for CA-125 as a screening tool for early-stage ovarian cancer, according researchers at the University of Texas M.D. Anderson Cancer Center.
The findings, presented in advance of the Annual Meeting of the American Society of Clinical Oncology, come from a study involving 3,252 women aged 50 to 74 years who were all healthy, postmenopausal, and had no strong family history of breast or ovarian cancer.
For the study, participants received a baseline CA-125 blood test and were assigned to one of three risks groups based on the Risk of Ovarian Cancer Algorithm (ROCA), a mathematical model based on the patient’s age and CA-125 score. Participants assigned to the “low”-risk group came back in a year for a follow-up blood test, those in the “intermediate” group required further monitoring with a repeat CA-125 blood test in 3 months, and those in the “high” group were referred to receive transvaginal sonography (TVS) and to see a gynecologic oncologist.
Researchers reported that based on the women’s CA-125 change over time, the average annual rate of referral to the intermediate and high groups were 6.8% and 0.9%, respectively. Overall, 85 women were determined to be high risk; they underwent TVS and were referred to a gynecologic oncologist.
Eight of those women had surgery; and five had ovarian cancer (three invasive cancers and two borderline cancers). Three of the women had benign tumors, for a positive predictive value of 37.5%. The screening failed to detect two borderline ovarian cancers.
Karen Lu, MD, professor in M.D. Anderson’s Department of Gynecologic Oncology, explained that the great importance of the findings was that the three invasive ovarian cancers detected were high-grade epithelial tumors, the most aggressive form of the disease, and that were caught early, when the disease is not only treatable but most often curable.
“As a clinician treating women with this disease for more than 10 years, I’ve become an admitted skeptic of ovarian cancer screening. Now, with these findings, I’m cautiously optimistic that in the not too distant future, we may be able to offer a screening method that can detect the disease in its earliest, curable stages and make a difference in the lives of women with this now-devastating disease,” said Dr. Lu.
For the future, Dr. Lu and her team revealed that they plan to look at combining other markers with CA-125 to determine the screening impact of their combined change over time.