Prognostic significance of tumor extension into venous system in patients undergoing surgical treatment for renal cell carcinoma with venous tumor thrombus.

ABSTRACT

AIMS: The objective of this study was to evaluate the prognostic significance of the extent of a tumor thrombus in renal cell carcinoma (RCC) involving the venous system. METHODS: This study included 135 consecutive RCC patients with a venous tumor thrombus undergoing radical nephrectomy and tumor thrombectomy between 1985 and 2009. These patients were classified based on the maximal level of the tumor thrombus extending into the venous system, as follows group 1, renal vein; group 2, infradiaphragmatic; and group 3, supradiaphragmatic. RESULTS: Of the 135 patients, 65, 49 and 21 were classified into groups 1, 2 and 3, respectively. The 1, 3 and 5-year cancer-specific survival (CSS) rates in these 135 patients were 89.2, 56.9 and 49.2%, respectively. Among several factors examined, tumor size, tumor grade, perirenal fat invasion and presence of metastasis, but not extent of tumor thrombus, were significantly associated with CSS on univariate analysis. Of these significant factors, only tumor size and presence of metastasis appeared to be independently related to CSS on multivariate analysis. When the patients without metastasis were analyzed separately, CSS in groups 2 and 3 was significantly poorer than that in group 1. CONCLUSIONS: These findings suggest the absence of a significant prognostic impact of the level of the tumor thrombus in a complete cohort of RCC patients with a venous tumor thrombus; however, it is warranted to determine whether the level of the tumor thrombus has different effects on the prognosis according to the presence of metastatic diseases.