Prognostic implication of capsular invasion without perinephric fat infiltration in localized renal cell carcinoma

Abstract

Objectives To analyze the prognostic value of capsular invasion without perinephric fat infiltration in patients with localized renal cell carcinoma (RCC) Stage pT1-pT2N0M0. Methods A total of 288 patients with RCC (conventional type) confined to the kidney (pT1-pT2N0M0) who underwent radical nephrectomy from January 1993 to November 2004 at our institution were included in our study. The disease of all patients was staged according to the 2002 TNM classification system. Pathologic findings, including T stage, nuclear grade, and capsular invasion, were retrospectively reviewed. Disease-specific survival was compared according to the capsular invasion. Results Tumor invasion of the renal capsule was identified in 108 (37.5%) of the 288 patients. Of the 230 patients with Stage pT1, 78 (33.9%) had lesions invading the renal capsule and 30 (51.7%) of 58 patients with Stage pT2 had capsular invasion. Involvement of the renal capsule was associated with a worse pT stage ( P = 0.015). The 5-year disease-specific survival rate for patients with no capsular invasion versus with capsular invasion was 91.8% versus 84.3%, respectively ( P = 0.132). For patients with pT1 tumors, the 5-year disease-specific survival rate was 95.6% for patients without capsular invasion and 92.6% for those with capsular invasion ( P = 0.299). For patients with pT2 tumors, the 5-year disease-specific survival rate was 90.5% for patients without capsular invasion and 73.8% for those with capsular invasion ( P = 0.031). Conclusions Renal capsular invasion is associated with a worse stage in localized RCC. Patients with Stage pT2 RCC and capsular invasion appear to have a worse prognosis than those with equivalently staged RCC without capsular invasion.