A comparison of methods for preoperative discrimination between malignant and benign adnexal masses: the development of a new logistic regression model

Abstract

Objective: The aim of this study was to assess the complementary use of ultrasonographic end points with the level of circulating CA 125 antigen by multivariate logistic regression analysis algorithms to distinguish malignant from benign adnexal masses before operation.

Study design: One hundred ninety-one patients aged 18 to 93 years with overt adnexal masses were examined by transvaginal ultrasonography with color Doppler imaging and 31 variables were recorded. The end points were the histologic classification of the tumor and the areas under the receiver-operator characteristic curves of alternative algorithms.

Results: One hundred forty patients had benign tumors and 51 (26.7%) had malignant tumors: 31 primary invasive tumors (37% International Federation of Gynecology and Obstetrics stage I), 5 tumors of borderline malignancy (100% International Federation of Gynecology and Obstetrics stage I), and 15 tumors were metastatic and invasive. The most useful variables for the logistic regression analysis were the menopausal status, the serum CA 125 level, the presence of >/=1 papillary growth (>3 mm in length), and a color score indicative of tumor vascularity and blood flow. The optimized procedure had a sensitivity of 95.9% and a specificity of 87.1%. The area under the receiver-operator characteristic curve was significantly higher (P <.01) than the corresponding values from the independent use of serum CA 125 levels or indexes of tumor form or vascularity.

Conclusion: Regression analysis of a few complementary variables can be used to accurately discriminate between malignant and benign adnexal masses before operation.