Comparison of ultrasound and tumor marker CA125 in diagnosis of adnexal mass malignancies

Background: CA125 is the most used tumor marker for ovarian cancer monitoring and diagnosis. This study aimed to evaluate the capacity to predict malignancy in women with adnexal tumors using CA125 measurement and ultrasound criteria before the pathological examination. Materials and Methods: This observational diagnostic study was conducted on 300 patients with obvious diagnosis of adnexal mass consists of ovarian masses, fallopian tubes, and masses within the broad ligament referring to Alzahra and Beheshti Hospitals from 2018 to 2019. Ultrasound examinations were done before surgery and malignancy risk was investigated by the ADNEX criterion. Sensitivity, specificity, positive and negative likelihood ratio (likelihood ratio [LR]+ and LR-), and area under the curve (AUC) were calculated. Results: From 284 patients, 260 masses were categorized in benign, 18 were in borderline, and 18 masses were malignant. The mean age of patients with malignant tumors was significantly higher than the others (P = 0.01). Differences in the level of CA-125 were not statistically significant (P = 0.78). Furthermore, the proportion of ascites in the malignant group (16.3%) was significantly higher than the others (P = 0.003). The AUC in ADNEX model (cutoff & GE;9%) for differentiation of benign and malignant tumors was 0.75 (95% confidence interval [CI]: 0.69-0.80) with a sensitivity of 0.63 (95% CI: 0.41-0.81) and a specificity of 0.80 (95% CI: 0.74-0.84). Receiver operating characteristic analysis for CA-125 revealed that this variable is not capable for discrimination between benign and malignant tumors as the AUCs of the aforementioned variable were 0.60, 0.60, and 0.52 for the whole patients, premenopause, and postmenopause categories. Conclusion: CA-125 marker, along with other ultrasound findings, can be more accurate in identifying the malignancy of the adnexa tumor.