Assessment of survival of patients with metastatic clear cell renal cell carcinoma after radical cytoreductive nephrectomy versus no surgery: a SEER analysis

PURPOSES: To examine the factors related to the choice of cytoreductive nephrectomy (CN) for patients with metastatic clear cell renal cell carcinoma (mCCRCC), and compare the population-based survival rates of patients treated with or without surgery in the modern targeted therapy era. MATERIALS AND METHODS: From 2006 to 2009, patients with mCCRCC were identified from SEER database. The factors that affected patients to be submitted to CN were examined and propensity scores for each patient were calculated. Then patients were matched based upon propensity scores. Univariable and multivariable cox regression models were used to compare survival rates of patients treated with or without surgery. Finally, sensitivity analysis for the cox model on a hazard ratio scale was performed. RESULTS: Age, race, tumor size, T stage and N stage were associated with nephrectomy univariablely. After the match based upon propensity scores, the 1-, 2-, and 3-year cancer-specific survival rate estimates were 45.1%, 27.9%, and 21.7% for the no-surgery group vs 70.6%, 52.2%, and 41.7% for the surgery group, respectively (hazard ratio 0.42, 95%CI: 0.35-0.52, log-rank P<0.001). In multivariable Cox proportional hazard regression model, race, T stage, N stage and median household income were significantly associated with survival. Sensitivity analysis on a hazard ratio scale indicated that the hazard ratio might be above 1.00 only when the unknown factor had an opposite effect on survival which was 3-fold than CN. CONCLUSION: The results of our study showed that CN significantly improves the survival of patients with metastatic CCRCC even in the targeted therapy era.