Objective: To determine the accuracy of tumour associated antigens CA 125, CA 15-3 and TAG 72.3 in the differential diagnosis of benign and malignant pelvic masses and to compare the results with a previously defined risk of malignancy index (RMI).
Design: Retrospective analysis of samples collected during a prospective observational study.
Setting: Department of Obstetrics and Gynaecology, the Royal London Hospital and Duke University Medical Center.
Subjects: One hundred and forty-three consecutive patients undergoing surgery for an adnexal mass.
Method: Tumour marker levels were determined by radio-immunoassay in stored serum samples obtained from 143 study subjects.
Results: The highest diagnostic accuracy of the tumour marker panel was achieved by defining a positive result as elevation of any two of CA 125 (> 30 u/ml), CA 15-3 (> 30 u/ml) and TAG 72.3 (> 10 u/ml), (sensitivity 66.7%, specificity 93.1%). Similar diagnostic accuracy could be achieved by CA 125 alone using an upper limit of 50 u/ml (sensitivity 66.7%, specificity 94.1%). Inclusion of CA 15-3 or TAG 72.3 in stepwise logistic regression analysis did not improve the discriminative performance of the RMI.
Conclusion: The risk of malignancy index incorporating CA 125, menopausal status and ultrasound is superior to the panel of three tumour markers for pre-operative differential diagnosis of the pelvic mass.