Purpose: The features predictive of aggressive behavior in stage pT1 conventional (clear cell) renal cell carcinoma are not completely known. We evaluated pathological features in a large series of stage pT1 conventional renal cell carcinoma cases and examined the association of these features with cancer specific survival.
Materials and methods: Patients with solitary stage pT1 conventional renal cell carcinoma who underwent radical nephrectomy between 1970 and 1997 were eligible for study. For each of the 46 patients who died of renal cell carcinoma we selected a stratified random sample of at least 3 year matched controls who were still alive or dead of other causes. The study included 277 patients. We evaluated patient age at nephrectomy, sex, tumor size, Fuhrman grade, necrosis and sarcomatoid component. Univariate and multivariate Cox proportional hazards models were fit to assess the features associated with cancer specific survival.
Results: Multivariate modeling revealed that tumor size, Fuhrman grade and necrosis were jointly significantly associated with cancer specific survival. Of the 4.5, 5 and 6 cm. tumor size cutoffs examined on univariate analysis a cutoff of 5 cm. or greater was most predictive of cancer specific survival.
Conclusions: In stage pT1 conventional renal cell carcinoma Fuhrman grade, tumor necrosis and tumor size together were jointly significantly associated with cancer specific survival. Specifically of the tumor size cutoffs analyzed the 5 cm. cutoff was most predictive of cancer specific survival.