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 CA 125 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.