Purpose: To analyze to what extent histologic subtype is of prognostic importance in renal cell carcinoma based on a large, international, multicenter experience.
Patients and methods: Four thousand sixty-three patients from eight international centers were included in this retrospective study. Histologic subtype (1997 International Union Against Cancer [UICC] criteria of tumor response), age, sex, TNM stage, Fuhrman grade, tumor size, Eastern Cooperative Oncology Goup performance status (ECOG PS), and overall survival were determined in all cases. The prognostic values of clear cell, papillary, and chromophobe histologic features were assessed by uni- and multivariate analysis using the Kaplan-Meier method and Cox model, respectively.
Results: Clear cell, papillary, and chromophobe carcinomas accounted for 3,564 (87.7%), 396 (9.7%) and 103 (2.5%) cases, respectively. In univariate analysis, a trend toward a better survival was observed when clear cell, papillary, and chromophobe histologies were considered prognostic categories (log-rank P = .0007). However, in multivariate analysis, TNM stage, Fuhrman grade and ECOG PS, but not histology, were retained as independent prognostic variables (P < .001).
Conclusion: The stratification in three main renal cell carcinoma histologic subtypes as defined by the 1997 UICC-American Joint Committee on Cancer consensus should not be considered a major prognostic variable comparable to TNM stage, Fuhrman grade and ECOG PS.