Renal vein or inferior vena caval extension in patients with renal cortical tumors: impact of tumor histology.

PURPOSE: We determined the prognostic significance of renal vein or inferior vena caval (IVC) extension in patients with nonmetastatic renal cell carcinoma (RCC) or oncocytoma undergoing surgery.

MATERIALS AND METHODS: The charts of patients undergoing radical or partial nephrectomy from 1989 to 2001 for nonmetastatic RCC or oncocytoma were retrospectively reviewed. A total of 1082 patients (1120 renal units) underwent radical (850 renal units) or partial (270 renal units) nephrectomy.

RESULTS: Renal vein extension was present in 60 patients (65.9%) and IVC extension was present in 31 (34.1%). The histological type associated with an increased risk of renal vein/IVC extension was conventional (80 of 702 cases, p <0.0001) and histological types with a decreased risk were oncocytoma (0 of 117, p = 0.00052) and papillary histology (0 of 146, p <0.0001). The 5-year actuarial recurrence-free probability was 59%, 65% and 91% in patients with IVC extension, renal vein extension and no renal vein or IVC extension, respectively. Larger tumor size, nodal metastases and conventional histology were associated with an increased risk of recurrence (RR = 3.38, 95% CI 2.53 to 4.51 for a doubling in size, RR = 9.97, 95% CI 5.51 to 18.1 and RR 3.78, 95% CI 2.15 to 6.65) as well as death (RR = 1.44, 95% CI 1.20 to 1.74 for a doubling in size, RR = 5.39, 95% CI 2.86 to 10.2 and RR = 1.56, 95% CI 1.09 to 2.24, respectively).

CONCLUSIONS: Conventional RCC is associated with an increased risk, and oncocytoma and papillary histology are associated with a decreased risk of renal vein or IVC extension. Renal vein or IVC extension alone does not impart a worse prognosis independent of tumor size, nodal status and histology.