EVALUATION OF THE DIAGNOSTIC PERFORMANCE OF THE ‘RISK OF MALIGNANCY INDEX’ IN DIFFERENTIATING BENIGN FROM MALIGNANT OVARIAN TUMORS

Abstract

Malignant ovarian tumors are the sixth most common female cancer and constitute 7.5% of all gynecological malignancies and 3.5% of all cancers in women (1). The overall mortality in ovarian malignancy is more than 80%, contributed largely by the delay in diagnosis. Early detection of ovarian cancer and timely referral, if required to a gynecological oncologist forms the corner stone to reduce mortality from ovarian malignancy. Ovarian tumors are known to present late in the course of the disease and there is no denite test to dene whether an ovarian mass is benign or malignant . The overall performance of the Ca 125 is rather poor, considering that it may be elevated in a number of benign conditions as well. Inter observer variability and the multitude of mimickers, precludes ultrasound as the sole tool to differentiate the two. A combination of the above along with the menopausal status promises to perform better in differentiating benign vs malignant masses. Hence rests the signicance of the RMI in this study. Also knowing whether an ovarian mass is benign or malignant will be helpful not only in prognosticating the disease and planning appropriate therapy , but it has the powerful advantage of deciding who should do the surgery – the general gynecologist or the oncosurgeon . Aim : The objective of this study is to evaluate the diagnostic performance of the Risk of Malignancy Index (RMI) in differentiating between benign and malignant ovarian tumors . Materials and methods : This study was conducted in the Department of Obstetrics and Gynecology – Government medical college Trivandrum for a period of one year. All patients above the age of 30 years, admitted to the wards with an ovarian mass were included in the study. RMI scores were calculated for all patients. The RMI scores were then compared to the histopathology reports, which is the gold standard for the diagnosis of malignancy. ROC curve was drawn to conclude on the cut off value. Results : Out of the 102 patients in the study group, 24 (23.5%) had a malignant ovarian tumor. The sensitivity, specicity, PPVand NPVof RMI was 83.3%, 88.46%, 68.99% and 94.52% respectively. The sensitivity, specicity, and NPV of RMI is much higher than the individual performance of ultrasound, menopause or serum Ca 125 levels. Conclusion :RMI has proved to be a good diagnostic method to differentiate benign and malignant ovarian tumors.