Prognostic Significance of Tumor Thrombus Level in Patients With Renal Cell Carcinoma and Venous Tumor Thrombus Extension. Is All T3b the Same?

Abstract

We investigated the prognostic significance of venous tumor thrombus extension in patients with renal cell carcinoma with particular emphasis on 2 questions. Does the level of thrombus in the inferior vena cava (IVC) impact long-term survival? Is there a difference in long-term survival when tumor thrombus is in the renal vein versus the IVC for patients classified as T3b by 1997 TNM staging? Between July 1970 and July 2000, 153 patients underwent surgical resection. Cancer specific survival was determined for different tumor thrombus levels in a retrospective fashion. Mean followup was 60 months with a range of 12 to 221. Level of tumor thrombus was renal vein (in 46), level I (in 68), level II (in 17) and level III (in 22). No demographic differences existed between the different levels including gender, age, perinephric extension, Fuhrman grade, percentage of metastatic disease and tumor size (Fisher's exact test). Patients with evidence of nodal disease or metastasis at surgery were eliminated from cancer specific survival analysis. The overall 10-year cancer specific survival for patients was 30%, 19% and 29% for level I, II and III, respectively. Patient survival at 5 and 10 years was not significantly different between the 3 IVC levels (p = 0.48). Ten-year survival of patients with renal vein involvement (66%) versus level I (29%) was significantly different (p = 0.0001). The level of tumor thrombus in the IVC does not significantly effect long-term survival. Ten-year survival of patients classified as T3b is statistically different for patients having tumor thrombus in the renal vein compared to level I. Combining these 2 groups as T3b by the 1997 TNM staging may need to be reevaluated.