Effectiveness of a multivariate index assay in the preoperative assessment of ovarian tumors.

OBJECTIVE To compare the effectiveness of physician assessment with a new multivariate index assay in identifying high-risk ovarian tumors. METHODS The multivariate index assay was evaluated in women scheduled for surgery for an ovarian tumor in a prospective, multi-institutional trial involving 27 primary- care and specialty sites throughout the United States. Preoperative serum was collected, and results for the multivariate index assay, physician assessment, and CA 125 were correlated with surgical pathology. Physician assessment was documented by each physician before surgery. CA 125 cutoffs were chosen in accordance with the referral guidelines of the American College of Obstetricians and Gynecologists. RESULTS The study enrolled 590 women, with 524 evaluable for the multivariate index assay and CA 125, and 516 for physician assessment. Fifty-three percent were enrolled by nongynecologic oncologists. There were 161 malignancies and 363 benign ovarian tumors. Physician assessment plus the multivariate index assay correctly identified malignancies missed by physician assessment in 70% of nongynecologic oncologists, and 95% of gynecologic oncologists. The multivariate index assay also detected 76% of malignancies missed by CA 125. Physician assessment plus the multivariate index assay identified 86% of malignancies missed by CA 125, including all advanced cancers. The performance of the multivariate index assay was consistent in early- and late-stage cancers. CONCLUSION The multivariate index assay demonstrated higher sensitivity and lower specificity compared with physician assessment and CA 125 in detecting ovarian malignancies.