RT Journal Article SR Electronic T1 1064 Role of CA 125, HE4 and IOTA simple rules in differentiating benign and malignant ovarian tumour JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A294 OP A294 DO 10.1136/ijgc-2021-ESGO.512 VO 31 IS Suppl 3 A1 A Bahadur A1 R Mundhra A1 N Bhattacharya YR 2021 UL http://ijgc.bmj.com/content/31/Suppl_3/A294.2.abstract AB Introduction/Background*This study aimed to evaluate the diagnostic added-value of serum CA-125 & HE4 to the International Ovarian Tumor Analysis (IOTA) Simple Rules for differentiating malignant and benign ovarian tumors preoperatively.Methodology A Cross sectional study was conducted in the Department of Obstetrics and Gynecology on 100 patients with ovarian masses. Demographic and clinical data were prospectively collected. Histopathologic diagnosis was used as the gold standard test. Evaluation of the utility of HE4, CA125 and IOTs simple rules for preoperative identification of malignacy was based on the increment of the area under the receiver operating characteristic curve (AuROC).Result(s)*Out of the 50 suspected benign masses as per IOTA simple rules, post surgery (considering histopathology as gold standard) 32 (64%) were diagnosed as benign ovarian masses, 4 (8%) borderline and 14 (28%) other malignant ovarian tumors on final histopathology. Out of 50 suspected malignant masses as per IOTA simple rules, 26 (52%) were finally diagnosed as benign, 4(8%) borderline and 20 (40%) were malignant. Sensitivity of combined testing of both tumour markers (HE4 and Ca-125) and IOTA together was calculated to be a 85.3% (69-95) whereas its specificity increased to be 94.8% (86-99). Positive predictive value was determined to 90.6% (75-98) and negative predictive value was calculated 91.7% (82-97) making its diagnostic accuracy as 91.3% (84-96).Conclusion*Combining IOTA Simple rules with knpown tumour markers (CA125 and HE4) increases diagnostic accuracy in predicting malignat ovarian masses preoperatively