Comparison of two malignancy risk indices based on serum CA125, ultrasound score and menopausal status in the diagnosis of ovarian masses

Objective To evaluate the ability of two malignancy risk indices (RMI 1 and RMI 2) incorporating menopausal status, serum CA125 level and ultrasound findings, to discriminate a benign from a malignant pelvic mass. Design A retrospective study. Setting Department of Obstetrics and Gynaecology, University of Siena, Italy. Population One hundred and twenty-four women over 30 years of age admitted consecutively between January 1995 and December 1997 for surgical excision of ovarian masses. Main outcome measures The sensitivity, specificity, and positive predictive value of serum CA125, ultrasound findings and menopausal status, separately and combined into the RMI 1 and RMI 2, to diagnose ovarian cancer. Results The RMI 1 and RMI 2 were more accurate than menopausal status, ultrasound findings, and CA125 separately in diagnosing cancer. For all cut off values between 80 and 250, RMI 2 performed better than RMI 1. The RMI 2 at a cut off level of 125 gave a sensitivity of 81%, specificity of 90%, and positive predictive value of 74%. Conclusions We found that RMI 2 was more reliable in discriminating benign and malignant ovarian disease than RMI 1. RMI is a simple method which can be used in gynaecology clinics and less specialised centres.