EP23.65: Serum Ca‐125 levels in postmenopausal women with adnexal masses and risk stratification based on Ovarian‐Adnexal Reporting and Data System

To analyse if there are differences in serum Ca-125 levels in postmenopausal women with adnexal masses and their risk stratification based on Ovarian-Adnexal Reporting and Data System (O-RADS). Ambispective observational study based on ultrasound data collected at a University Hospital with a gynecologic oncology unit between 2012 and 2023. Two IOTA-certified level III gynecologists classified adnexal masses using the O-RADS system to stratify malignancy risk. We included postmenopausal women with available data of serum Ca-125 levels. We analysed the difference between groups using ANOVA. 246 postmenopausal women with adnexal masses were candidates to enter the study, of which 164 (67%) were included when they met the classification criteria for their evaluation based on serum Ca-125 levels. The mean age of the total population was 60.6 (±) 9.8 years. The results are presented in table 1 according to each O-RADS category. In our experience, there are statistically significant differences between the O-RADS categories and serum levels of Ca-125. This demonstrates that the patients' age and their Ca-125 levels increase linearly with the risk of malignancy. Category (n / %) Age in years (Mean / Standard deviation) Ca-125 in UI/L (Median / Interquartile range) O-RADS 2 18 (11%) O-RADS 3 63 (38%) O-RADS 4 46 (28%) O-RADS 5 37 (23%)