Comparison of three malignancy risk indices and CA-125 in the preoperative evaluation of patients with pelvic masses

Abstract Background Patients with pelvic mass are the most referred patients to gynecologist. The aim of this study was to evaluate the ability of three malignancy risk indices (RMI 1, RMI 2 and RMI 3) and CA-125 to discriminate a benign from a malignant pelvic mass in our region (North of Iran). Methods This retrospective study was performed on 182 women with pelvic masses referred to Yahyanejad Hospital from 2007 to 2009. Ultrasound scans were scored as one point for each of the following characteristics: multilocular cyst, solid areas, intra-abdominal metastases, ascites, and bilateral lesions. For each patient a total ultrasound score (U) was calculated. The difference of the three RMI was based on the allocation of the U and M scores. The sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) of level of serum CA-125, the RMI 1, 2 and 3 were compared. Results Mean age of the patients was 39.9 ± 9.3 years. Most of them were premenopausal (161 women or 88.4%). A significant linear trend for malignancy was found by increasing age, ultrasound score, and serum CA-125. The best performance of CA125 was at a cut-off 88 U/ml, with a sensitivity of 88%, a specificity of 97%, a positive predictive value of 84%, and a negative predictive value of 99%. RMI 1 and 3 at the optimal cut off point of 265 and RMI2 at the optimal cut off point of 355, had a sensitivity of 91%, specificity of 96%, a positive predictive value of 78%, and a negative predictive value of 99%. Conclusion In our population we found that there is no statistically significant difference in the performance of three malignancy risk indices (RMI 1, RMI 2, and RMI 3) and CA125 in differentiating between benign and malignant pelvic masses.