Proposal for Reclassification of the TNM Staging System in Patients with Locally Advanced (pT3–4) Renal Cell Carcinoma According to the Cancer-Related Outcome

Abstract

ObjectivesThe optimal stratification of locally advanced renal cell carcinoma (RCC) is controversial, with the prognostic relevance of ipsilateral adrenal gland invasion and cranial extension of vena cava thrombosis being the most debatable issues. We evaluated the prognosis of patients with locally advanced RCC and identified a new model to stratify their outcome. Materials and methodsWe analyzed the data of 227 patients who had undergone partial or radical nephrectomy for pT3–4 RCC at two academic centers between 1986 and 2002. The log-rank test and Cox proportional hazards model were used for univariate and multivariate analysis, respectively. ResultsAt a median follow-up of 29 mo, we censored 108 (47.6%) cancer-related deaths. On univariate analysis, the 2002 T stage was not statistically significant. According to cancer-related outcome, we identified three subgroups of patients with different prognoses: pT3a(n): tumors with perirenal fat invasion or renal vein thrombosis or thrombosis within the vena cava below the diaphragm; pT3b(n): tumors with renal vein thrombosis or thrombosis within the vena cava below the diaphragm and concomitant perirenal fat invasion; pT4(n): adrenal gland or Gerota fascia invasion or thrombosis within the vena cava above the diaphragm. The three subgroups had significantly different prognoses. The new reclassification was an independent predictive variable on multivariate analysis, as well as the pathologic lymph node stage. ConclusionsThe 2002 version of TNM of locally advanced RCC did not stratify patient outcome. The present study suggests the possibility of reclassifying pT3–4 RCC into three categories capable of predicting cancer-specific survival, regardless of all other prognostic factors.