The estimation of the probability of tumor malignacy on the basis of test combination in the primary diagnosis of adnexal tumors

Abstract

Summary Purpose: The aim was to evaluate the risk of ovarian tumor malignancy based on logistic regression analysis and to construct a practical tool which might be used at the bedside. Material and methods: 379 women with adnexal masses were enrolled to the study. The results of the twodimensional (2D) gray-scale ultrasound examination, color and spectral Doppler blood flow measurement, threedimensional (3D) sonoangiography examination and serum levels of CA-125 measurement were analyzed. 160 out of 379 women with abnormal findings, (42.2%), were diagnosed with a malignant ovarian tumor, and 219 (57.8%) were found to have a non-malignant adnexal mass. To improve the sensitivity and specificity of ultrasound scan findings, postmenopausal status and preoperative serum CA-125 levels, the risk of malignancy index (RMI) was calculated and compared to the result of logistic regression analysis. Furthermore, the nomograms applicable at the bedside for estimation of the probability of malignancy for the examined adnexal tumor were derived. Results: The highest values of the area under the receiver operating characteristic (ROC) curves in univariate analysis were 0.87 for serum levels of CA-125 and 0. 83 for the color score. For the RML, the value of the area under ROC curve was 0.91. The results of logistic regression revealed that papillary growth, color score, age, pulsatility index (PI) and level of serum CA 125 were significant factors in the multivariate model. The obtained classification accuracies for MLRA model in the training set and the test set were 88% and 92%, respectively. The value of the area under the ROC curve was 0.94 and significantly differed from the value of area for CA-125 (p<0.05). Conclusions: The results of the study suggest that the combined use of ultrasound parameters and serum level of CA-125 in the prognostic model improves the diagnostic precision in the primary discrimination of benign and malignant ovarian tumors in women.