EP619 Clinical implications of molecular profiling in patients with primary endometrial cancer

Introduction/Background In patients with endometrial cancer after surgery adjuvant therapy is frequently administered. In general, indication for adjuvant treatment is established based on clinical pathologic parameters such as patients age, depth of infiltration and pathologic grading. However, although survival has improved, there are still patients over and under treated. Currently, an ongoing prospective trial evaluates risk stratification of patients and treatment modification according to molecular profiling of tumor tissue. This retrospective analysis was performed to investigate, whether molecular profiling of tumor tissue has implication on and is feasible in daily routine. Methodology This study included all patients with primary endometrioid endometrial cancer treated at Medical University Vienna between 2017 and 2018. In addition to conventional pathologic analysis, tumor samples were molecular pathologically analyzed. Molecular pathologic evaluation included analysis for micro satellite instability, gen sequencing of 161 different genes, advanced analysis for lymph vascular space invasion and L1CAM analysis. Patients were then stratified into 4 risk groups as previously described. Results In total 43 patients were included into this analysis. In 37 cases risk stratification was possible. Microsatellite instability, mutation in the POLE gene locus, and TP53 mutations were described in 5 (11.6%), 3 (7%), und 3 (7%) cases respectively. In 8 (18.6%) cases molecular profiling would have had an impact on adjuvant treatment. In three cases additional treatment would have been suggested while in five cases molecular profiling would have suggested to restrain from adjuvant treatment. Conclusion Molecular profiling is feasible in daily routine, and did not delay therapy. In this small group of patients molecular profiling of tumor tissue would have changed adjuvant treatment in roughly 20% of patients. The current results underline the importance of the PORTEC-4a study that investigates risk stratification of patients according to molecular profiling. Disclosure RS Travel expenses: Amgen, Pharma Mar, Roche SP Consultant AstraZeneca, Celgene, MSD, PharmaMar, Roche,Roche Diagnostics, Meda Pharma, Tesaro, Vifor Pharma, outside the submitted work. CG Consultant: AstraZeneca, Celgene, MSD, PharmaMar, Roche, Tesaro, Vifor Pharma Speaker: Amgen, AstraZeneca, MSD, PharmaMar, Roche, Tesaro Direct research funding: Meda Pharma, Roche Diagnostics AR Research grants: Roche Honoraria as a speaker and for advisory boards: Amgen, Astra Zeneca, MSD, Pharma Mar, Roche, Tesaro, Vifor Pharma Travel expenses: Amgen, Astra Zeneca, Pharma Mar, Roche, Tesaro.