Discrimination Between Benign and Malignant Adnexal Masses by Specialist Ultrasound Examination Versus Serum CA-125

Abstract

BACKGROUND: Subjective evaluation of gray-scale and Doppler ultrasound findings (i.e., pattern recognition) by an experienced examiner and preoperative serum levels of CA-125 can both discriminate benign from malignant adnexal (i.e., ovarian, paraovarian, or tubal) masses. We compared the diagnostic performance of these methods in a large multicenter study. METHODS: In a prospective multicenter study--the International Ovarian Tumor Analysis--1066 women with a persistent adnexal mass underwent transvaginal gray-scale and color Doppler ultrasound examinations by an experienced examiner within 120 days of surgery. Pattern recognition was used to classify a mass as benign or malignant. Of these women, 809 also had blood collected preoperatively for measurement of serum CA-125. Various levels of CA-125 were used as cutoffs to classify masses. Results from both assays were then compared with histologic findings after surgery. RESULTS: Pattern recognition correctly classified 93% (95% confidence interval [CI] = 90.9% to 94.6%) of the tumors as benign or malignant. Serum CA-125 correctly classified at best 83% (95% CI = 80.3% to 85.6%) of the masses. Histologic diagnoses that were most often misclassified by CA-125 were fibroma, endometrioma, and abscess (false-positive results) and borderline tumor (false-negative results). Pattern recognition correctly classified 86% (95% CI = 81.1% to 90.4%) of masses of these four histologic types as being benign or malignant, whereas a serum CA-125 at a cutoff of 30 U/mL correctly classified 41% (95% CI = 34.4% to 47.5%) of them. Pattern recognition assigned a correct specific histologic diagnosis to 333 (59%, 95% CI = 54.5% to 62.8%) of the 567 benign lesions. CONCLUSION: Pattern recognition was superior to serum CA-125 for discrimination between benign and malignant adnexal masses.