Cancer - Bladder, Pelvis, Ureter & Others(구연) Oral Session 5 / Cancer - Bladder, Pelvis, Ureter & Others (Ⅰ) (O-048) Rm.201 10월 30일(수) 15:00-16:00 국내 요로상피암 환자에서 PD-L1 발현률에 대한 조사: 후향적, 다기관 연구 동국대학교 일산병원 비뇨기과학교실¹,화순전남대학교병원²,이화여대 부속 목동병원³,서울대학교병원⁴, 부산대학교병원5, 중앙대학교병원6, 강동 경희대학교병원7, 국립암센터8, 성균관의대 삼성서울병원9 김형석¹,정승일²,이동현³,송완³,구자현⁴,구자윤5,최세영6,장인호6,최태수7,서호경8,전성수9,그리고 방광암 연구회 Objective: To investigate programmed death-ligand 1 (PD-L1) expression status and to evaluate the factors related to positive PD-L1 expression in Korean urothelial carcinoma (UC) patients. Materials and Methods: Data of 448 UC patients who explored PD-L1 expression using VENTATA (SP-142 immunohistochemical staining) test between February 2016 and June 2019 were retrospectively reviewed. PD-L1 expression level was categorized into three groups based on immune cell (IC) score as follows: IC0 (<1%), IC1 (≥1% and <5%), and IC2/3 (≥5%). Positive PD-L1 expression was defined as IC2/3 (≥5%). The predictors of positive PD-L1 expression were assessed using uni- and multivariate logistic regression analysis. Results: In the entire cohort, 249 (55.6%) patients presented with expression levels of IC1/2/3 (≥1%), and 133 (29.7%) patients showed expression levels of IC2/3 (≥5%). Multivariate analyses for positive PD-L1 expression revealed that advanced age (≥70 years) (hazard ratio [HR] 0.610, 95% confidence interval [CI] 0.400-0.930), upper tract specimen (HR 0.307, 95% CI 0.139-0.679), advanced tumor stage (stage III/IV) (HR 2.059, 95% CI 1.292-3.282), and high tumor grade (HR 3.416, 95% CI 1.298-8.990) were independent predictors of positive PD-L1 expression. Conclusions: Our data suggest that positive PD-L1 expression was observed in approximately 30% of the UC patients in Korea. Besides, positive PD-L1 expression was significantly correlated with age, type of specimen, tumor stage, and tumor grade. Further studies evaluating the association between PD-L1 expression and response to systemic immunotherapy using immune checkpoint inhibition are required. keywords : Urothelial carcinoma, programmed death-ligand 1, immunohistochemistry