Should CA-125 go the way of the dinosaur?

Expert evaluation of gray-scale and color Doppler ultrasound findings (i.e., pattern recognition) is superior to serum CA-125 for discriminating between benign and malignant adnexal masses, according to the findings of a prospective, multicenter study involving 1,066 women with a persistent adnexal mass.

The International Ovarian Tumor Analysis found that subjective evaluation of gray-scale and Doppler findings by an experienced examiner within 120 days of surgery correctly classified 93% (95% CI, 90.9%–94.6%) of the tumors, while serum levels of CA-125 correctly classified only 83% at best (95% CI, 80.3%–85.6%). The diagnoses most often misclassified by serum CA-125 were fibroma, endometrioma, and abscess (false-positive results) and borderline tumor (false-negative results). Pattern recognition diagnosed these four conditions correctly 86% of the time (95% CI, 81.1%–90.4%), while serum CA-125 at a cutoff of 30 U/mL diagnosed them correctly less than half (41%) of the time (95% CI, 34.4%–47.5%).

Van Calster B, Timmerman D, Bourne T, et al. Discrimination between benign and malignant adnexal masses by specialist ultrasound examination versus serum CA-125. J Natl Cancer Inst. 2007;99:1706-1714.