Evaluation of the Accuracy of Risk of Malignancy Index in Distinuishing Benign and Malignant Ovarian Tumour in a Nigerian Population

Abstract

ABSTRACT

BACKGROUND: Ovarian cancer is one of the deadliest gynaecological cancer. Preoperative differentiation between benign and malignant ovarian mass in women can be problematic with no test or algorithm being superior in terms of accuracy. The risk of malignancy index (RMI 1) combines three pre-surgical features: serum CA-125, menopausal status (M) and ultrasound score (U). The RMI is a product of the ultrasound score, the menopausal status and the serum CA125 level IU/ml.OBJECTIVES: To determine if RMI can accurately differentiate benign from malignant ovarian masses in women RESEARCH METHODS: The study was a descriptive cross-sectional study carried out in Federal Teaching Hospital Katsina between April to November 2018. Sixty Patients from the gynaecological unit scheduled for laparotomy who met the inclusion criteria were recruited after obtaining their consent. RMI was calculated and the results obtained were compared with the final histopathologic diagnosis. Statistical analysis was done using SPSS 20 and the level of significance was <0.05%. RESULTS: Risk of Malignancy index 1,2,3,4 were able to accurately distinguish between benign and malignant ovarian tumours in all women, the sensitivity was 80%, specificity 100%, positive predictive value 100%, negative predictive value 87.5% and accuracy 91.7%. All four RMIs performed equally however RMI 4 had the greatest AUC. CONCLUSION: The study validated RMI as being able to accurately distinguish benign and malignant ovarian tumours in the population studied.RECOMMENDATION: RMI should be used in preoperative evaluation of women with adnexal masses in FMC Katsina, KEYWORDS: CA 125, Perimenopause, Risk of Malignancy Index.