Prognostic factors associated with long-term survival in previously untreated metastatic renal cell carcinoma

Purpose: To identify prognostic factors (PF) for long-term survival in metastatic renal cell carcinoma (RCC) patients. Methods: We retrospectively reviewed a metastatic RCC database at the Cleveland Clinic Foundation consisting of 358 previously untreated patients who were enrolled in institutional review board-approved clinical trials of immunotherapy and/or chemotherapy at our institution from 1987 to 2002. In order to identify patient characteristics associated with long-term survival, we compared 226 'short-term' survivors [defined as overall survival (OS) < 2 years] with 31 'long-term' survivors (OS >= 5 years). Results: Using logistic regression models, four adverse PF were identified as independent predictors of long-term survival: hemoglobin less than the lower limit of normal, greater than two metastatic sites, involved kidney (left), and Eastern Cooperative Oncology Group (ECOG) performance status (PS). Using the number of poor prognostic features present, three distinct risk groups could be identified. Patients with 0 or 1 adverse prognostic feature present had an observed likelihood of long-term survival of 32% (21/66) compared with 9% (8/91) for patients with two adverse features present and only 1% (1/93) for patients with more than two adverse features. Conclusions: Independent predictors of long-term survival in previously untreated metastatic RCC include baseline hemoglobin level, number of involved sites, involved kidney, and ECOG PS. Incorporation of these factors into a simple prognostic scoring system enables three distinct groups of patients to be identified.