Abstract
BACKGROUND: Stage T1a renal cell carcinoma (RCC) (tumors <4 cm) is usually curable. Nephron-sparing partial nephrectomy (PN) has replaced radical nephrectomy (RN) as the standard of care for these tumors. Radical nephrectomy remains the first alternative treatment option, whereas percutaneous ablation (PA), a newer, nonsurgical treatment, is recommended less strongly because of the relative paucity of comparative PA data. OBJECTIVE: To compare PA, PN, and RN outcomes. DESIGN: Observational cohort analysis using inverse probability of treatment-weighted propensity scores. SETTING: Population-based SEER (Surveillance, Epidemiology, and End Results) cancer registry data linked to Medicare claims. PATIENTS: Persons aged 66 years or older who received treatment for T1a RCC between 2006 and 2011. INTERVENTIONS: PA versus PN and RN. MEASUREMENTS: RCC-specific and overall survival, 30- and 365-day postintervention complications. RESULTS: 4310 patients were followed for a median of 52 months for overall survival and 42 months for RCC-specific survival. After PA versus PN, the 5-year RCC-specific survival rate was 95% (95% CI, 93% to 98%) versus 98% (CI, 96% to 99%); after PA versus RN, 96% (CI, 94% to 98%) versus 95% (CI, 93% to 96%). After PA versus PN, the 5-year overall survival rate was 77% (CI, 74% to 81%) versus 86% (CI, 84% to 88%); after PA versus RN, 74% (CI, 71% to 78%) versus 75% (CI, 73% to 77%). Cumulative rates of renal insufficiency 31 to 365 days after PA, PN, and RN were 11% (CI, 8% to 14%), 9% (CI, 8% to 10%), and 18% (CI, 17% to 20%), respectively. Rates of nonurologic complications within 30 days after PA, PN, and RN were 6% (CI, 4% to 9%), 29% (CI, 27% to 30%), and 30% (CI, 28% to 32%), respectively. Ten percent of patients in the PN group had intraoperative conversion to RN. Seven percent of patients in the PA group received additional PA within 1 year of treatment. LIMITATIONS: Analysis of observational data may have been affected by residual confounding by provider or from selection bias toward younger, healthier patients in the PN group. Findings from this older study population are probably less applicable to younger patients. Use of SEER-Medicare linked files prevented analysis of patients who received treatment after 2011, possibly reducing generalizability to the newest PA, PN, and RN techniques. CONCLUSION: For well-selected older adults with T1a RCC, PA may result in oncologic outcomes similar to those of RN, but with less long-term renal insufficiency and markedly fewer periprocedural complications. Compared with PN, PA may be associated with slightly shorter RCC-specific survival but fewer periprocedural complications. PRIMARY FUNDING SOURCE: Association of University Radiologists GE Radiology Research Academic Fellowship and Society of Interventional Radiology Foundation.