RT Journal Article SR Electronic T1 P134 The usability of CA 125 and HE4 tumour markers in the prediction and verification of complete tumour resection and progression free survival in advanced ovarian cancer patients JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A140 OP A140 DO 10.1136/ijgc-2019-ESGO.196 VO 29 IS Suppl 4 A1 Molnár, S A1 Maka, E A1 Bagoly, Z A1 Lampé, R A1 Póka, R A1 Hernádi, Z A1 Krasznai, Z YR 2019 UL http://ijgc.bmj.com/content/29/Suppl_4/A140.2.abstract AB Introduction/Background The goal of primary debulking surgery (PDS) of ovarian cancer is complete tumour reduction, since any residual tumour disproves overall survival. In later cases neoadjuvant chemotherapy may be an option. We aimed to investigate the use of CA 125 and HE4 preoperative levels in the prediction of complete tumour reduction during upfront surgery, and the use of postoperative marker levels in the verification of complete tumour reduction and progression-free survival (PFS).Methodology 88 advanced ovarian cancer patients (FIGO III-IV), operated between 2010.01.01-2015.12.31 who had attempted curative PDS, had CA 125 and/or HE4 results before and/or after the operation were included. Progression free survival was assessed through Kaplan-Meier analysis, Receiver Operative Characteristics (ROC) curves and area under curve (AUC) was used to evaluate the performance of CA 125 and HE4 markers.Results Preoperative HE4 levels differed significantly in cases of successful complete and incomplete reduction (median [IQR]: 192 [80.1–573.7] vs. 1044 [592.8–2912] respectively, p<0.0001). The ROC analysis gave an AUC of 0.82, and the sensitivity and specificity of complete reduction were 86.67% and 73.33% respectively, at a cut-off level of 496 pmol/l. Preoperative CA 125 proved to be less useful in distinguishing between the two groups. Postoperative HE4 levels differed significantly in the patients who underwent complete reduction from those with residual disease, median [IQR] levels were 54.2 [39.2–82.05] vs. 364.9 [123.3–809.9] respectively (p<0.0001). HE4 also proved more useful in the prediction of >1 year PFS: AUC 0.786 and at a cut-off level of 138, sensitivity and specificity of >1 year PFS were 75% and 75% respectively (p<0.001).Conclusion HE4 proved to be a more useful preoperative tool in the selection of patients for future successful complete reduction. Postoperative HE4 levels might be used as an independent quality assurance marker for the verification of complete reduction and for prediction of PFS.Disclosure Nothing to disclose.