Currently, there are no established screening strategies for ovarian cancer and most women have advanced disease when they are diagnosed. Karen Lu, MD, of The University of Texas M.D. Anderson Cancer Center in Houston, TX, and colleagues recently tested the potential of a two-stage ovarian cancer screening strategy that incorporated changes in carbohydrate antigen 125 (CA-125) levels over time.2 In their 11-year study, 4,051 postmenopausal women initially underwent an annual CA-125 blood test. Using an ovarian cancer risk algorithm, the researchers divided the women into three risk groups (low, intermediate, and high). Those women who were classified as low risk received another CA-125 test 1 year later, those classified as intermediate risk received a repeat CA-125 after 3 months, and women classified as high risk received a transvaginal ultrasound and were referred to a gynecologic oncologist.
Of the women in this study, 5.8% were found to be of intermediate risk each year. The average annual referral rate to transvaginal ultrasound and review by a gynecologic oncologist was 0.9%. In this study, 10 women underwent surgery based on their ultrasound exams. The data revealed that the positive predictive value was 40% for detecting invasive ovarian cancer when using this approach, and the specificity of the testing strategy was 99.9%.
The findings suggest that this type of screening strategy may achieve high specificity with very few false-positive results, and that using a longitudinal screening strategy that looks at changes in CA-125 levels over time may be beneficial for postmenopausal women with an average risk of developing ovarian cancer. However, the researchers caution that further research is warranted before this screening strategy can be adopted for clinical use.
- Kanchi KL, Johnson KJ, Lu C, et al. Integrated analysis of germline and somatic variants in ovarian cancer. Nat Commun. 2014;5:3156.
- Lu KH, Skates S, Hernandez MA, et al. A 2-stage ovarian cancer screening strategy using the Risk of Ovarian Cancer Algorithm (ROCA) identifies early-stage incident cancers and demonstrates high positive predictive value. Cancer. 2013;119(19):3454-3461.