Diagnostic Accuracy of Preoperative Prediction of Malignancy in Ovarian Cysts

Abstract

In this review, we will critically evaluate the evolution of the diagnostic tools used in the prediction of ovarian malignancy preoperatively, that has shown to get a better outcome for ovarian cancer patients. It will triage women to the best place for their surgery and by ensuring the expertise available to perform the surgery reducing the rate of incomplete primary surgery, that has reflected into improve survival of ovarian cancer patients. The Risk of Malignancy Index (RMI) was the first diagnostic tool developed to help clinicians differentiate between benign and malignant ovarian tumours. Jacob et al. [1] described how it was developed and assesses its performance amongst a cohort 143 patients referred to a London hospital for elective surgical investigation of an adnexal mass. Each patient had five criteria assessed preoperatively: age, menopausal status, and clinical impression score (as determined by an experienced gynaecologist using all of the patient’s preoperative clinical information; out of 5, high = more likely to be malignant), ultrasound score (out of 5, high = more likely to be malignant), and CA-125 level. Following surgery, it was determined that 101 of the patients had benign masses and 42 had malignant tumours. Patients in the malignant group had a higher mean age, were more commonly post-menopausal, and had higher clinical impression scores, ultrasound scores and CA-125 levels than patients in the benign group; all of these differences were statistically significant. However, when used individually, the criteria had inadequate sensitivity and specificity for malignancy. Logistic regression analysis revealed that only menopausal status, ultrasound score and CA-125 levels were significantly and independently related to the likelihood ratio for malignancy. These three criteria were then combined to form the RMI: RMI = U × M × CA-125 U = 0 for ultrasound score of 0 = 1 for ultrasound score of 1 = 3 for ultrasound score of 2-5 M = 1 if premenopausal = 3 if postmenopausal When a cutoff score of 200 was used, the RMI showed excellent diagnostic performance, with a sensitivity of 85% and a specificity of 97%. Patients with an RMI score in excess of 200 had 42 times the background risk of cancer, whilst those with a score less than 200 had 0.15 times the risk. The authors concluded that the RMI was a valuable tool for the preoperative assessment of benign and malignant adnexal masses, and that it gave a higher level of discrimination than could be achieved by individual criteria alone. Overall, this is a good study. The sample size was sufficiently large to allow statistically significant differences between groups to be seen. The criteria used for the RMI were not chosen at