A population-based competing-risks analysis of survival after nephrectomy for renal cell carcinoma

OBJECTIVES: Variability in survival after surgical treatment is observed in patients with renal cell carcinoma (RCC), thereby affirming the heterogeneity of the disease. The aim of our study was to provide a clinically relevant and detailed assessment of survival following surgical excision in patients with RCC of all stages according to age, stage, and grade.

MATERIALS AND METHODS: A retrospective population-based analysis of 42,090 patients in the United States who were treated with partial nephrectomy (PN) or radical nephrectomy (RN) for RCC of all stages between the years 1988 and 2008 was performed. Competing-risks Poisson regression analyses focusing on cancer-specific mortality (CSM) or other-cause mortality (OCM) were executed. Stratification was performed according to age groups (≤ 59, 60-69, 70-79, and ≥ 80 y), the American Joint Committee on Cancer stage (I, II, III, and IV), and the Fuhrman grade (I-II and III-IV).

RESULTS: Increasing stage was associated with higher CSM rates (from 2%-9% to 54%-79% for stage I and IV), regardless of age. Similarly, high tumor grade was associated with higher CSM rates (from 2%-64% to 6%-79% for low and high grade). However, OCM was nonnegligible amongst persons aged 70 to 79 years (11%-24%) and ≥ 80 years (17%-44%), regardless of stage and grade. In subanalyses focusing on stage I RCC, CSM (3%-10%) rates were slightly higher for RN-treated patients, regardless of age and grade. However, in individuals aged 70 to 79 years with high-grade RCC, OCM rates were slightly higher for PN relative to RN (25.5% vs. 23.5%). In those aged ≥ 80 years, OCM rates were higher for PN compared with RN, both for low-grade (39.4% vs. 32.7%) and high-grade disease (52.0% vs. 42.8%).

CONCLUSIONS: Tumor grade and American Joint Committee on Cancer stage represent important prognostic factors for the prediction of CSM, despite adjustment for patient age. However, OCM rates were nonnegligible in elderly individuals (≥ 70 y) with low-grade and stage I to III RCC.