Cancer - Kidney(구연) Oral Session 5 / Cancer - Kidney (Ⅰ) (O-046) Grand Ballroom(2F) 11월28일(수) 14:00-15:00 Accurate risk assessment of patients with pathologic T3aN0M0 renal cell carcinoma 분당서울대학교병원 비뇨의학교실 오종진, 이민호, 이정근, 송병도, 이학민, 이상철, 변석수, 이상은, 홍성규 Objectives To develop a more precise risk-stratification system by investigating the prognostic impact of tumor growth within fatty tissues surrounding the kidney and/or renal vein. Patients and Methods We conducted a retrospective review of the medical records of 211 patients with a pathologic diagnosis of T3aN0M0RCC among 4,483 renal cell carcinoma (RCC) patients from February 1988 to December 2015 according to the number of T3a pathologies—extrarenal fat invasion (EFI) and/or renal venous invasion (RVI). Results During a mean follow-up duration of 38.8 months, the patients with both pathologies (EFI + RVI) had lower recurrence free survival (RFS) rate than those with only a single pathology (p = 0.001). Using multivariable Cox regression analysis, the presence of both factors was shown to be an independent predictor of RFS (HR = 1.964, p = 0.032); cancer specific survival rate was not different among patients with EFI and/or RVI. Patients with pathologic T3aN0M0 RCC presenting with both EFI and RVI were at an increased risk of recurrence following nephrectomy. Conclusion Therefore, pathologic T3a RCC could be sub-divided into those with favorable and unfavorable disease according to presence of EFI and/or RVI pathologies. keywords : Renal cell carcinoma, Prognostic impact, Extrarenal fat invasion