Cancer - Kidney(구연) Oral Session 5 / Cancer - Kidney (Ⅰ) (O-050) Grand Ballroom(2F) 11월28일(수) 14:00-15:00 단측성 및 양측성 신세포암의 예후 비교 서울대학교 의과대학 비뇨기과학교실, 분당서울대학교병원 비뇨기과 김정권, 이학민, 오종진, 이상철, 홍성규, 이상은, 변석수 Objectives: To investigate whether the distinction between unilateral and bilateral renal cell carcinoma (RCC) reflects differential biological activity and survival outcomes. Materials and Methods: We analyzed clinical data from a total of 2169 (98.0%) patients diagnosed with unilateral RCC and 44 (2.0%) patients diagnosed with bilateral RCC including 22 (50.0%) with synchronous (diagnosed concomitantly or within 3 months of the former tumor) and 22 (50.0%) with metachronous RCC at our institution. Comparative analysis of unilateral and bilateral RCC groups was conducted using propensity score matching analysis. Subgroup analysis of bilateral RCC including synchronous and metachronous RCCs was also performed. Results: The mean patient age was 55.2 ± 13.2 years, and the median follow-up period was 35.5 (interquartile range, 7-76) months. Based on propensity score matching, the two groups were well balanced. In the matching cohort, recurrence occurred in 11 (6.3%) patients overall including 5 (3.8%) in the unilateral RCC group and 6 (13.6%) in the bilateral RCC group. Kaplan-Meier survival analysis showed s significantly decreased 5-year recurrence-free survival (RFS, 82.6% vs. 94.3%, log-rank test, p=0.045, Figure 1A) in the bilateral RCC group compared with the unilateral group. In subgroup analysis, the metachronous RCC group showed significantly smaller mean pathologic tumor size (18.3 ± 12.6 mm vs. 40.1 ± 38.8 mm, p=0.011), and more favorable pathologic T stage (p=0.036) compared with synchronous RCC group. Kaplan-Meier survival analysis showed significantly decreased 5-year RFS in synchronous RCC compared with metachronous RCC (74.7% vs. 92.9%, log-rank test, p=0.028, Figure 1B). Conclusions: The bilateral RCC group showed significantly decreased 5-year RFS compared with the unilateral RCC group. Importantly, the synchronous RCC group manifested more adverse features than the metachronous group. keywords : bilaterality, renal cell carcinoma, synchronous