Cancer-specific mortality in T1a renal cell carcinoma treated with local tumor destruction versus partial nephrectomy

Abstract

Background: Large-scale analyses addressing cancer-specific mortality (CSM) in T1a renal cell carcinoma (RCC) patients treated with local tumor destruction (LTD), relative to partial nephrectomy (PN), are scarce. Objective: To compare CSM after LTD versus PN. Design, setting, and participants: Within the Surveillance, Epidemiology, and End Results (SEER) database (2004-2018), we identified patients with clinical T1a stage RCC treated with LTD or PN. Outcome measurements and statistical analyses: After 1:1 ratio propensity score match-ing (PSM) between patients treated with LTD versus PN, competing risks regression (CRR) models addressed CSM, after adjustment for other-cause mortality (OCM) and other covariates (age, tumor size, tumor grade, and histological subtype). Results and limitations: Relative to the 35 984 PN patients, 5936 LTD patients were older and more frequently harbored unknown RCC histological subtype or unknown grade. After 1:1 PSM that resulted in 5352 LTD versus 5352 PN patients, the 10-yr CSM rate was 8.7% versus 5.5%. In multivariable CRR models, LTD was associated with higher CSM, relative to PN (hazard ratio [HR]: 1.58, p < 0.001). Subgroup analyses revealed invariably higher CSM after LTD versus PN in patients with tumor size <= 3 cm (10-yr CSM 7.2% vs 5.3%, multivariable HR: 1.47, p < 0.001) and in patients with tumor size 3.1-4 cm (10-yr CSM 11.4% vs 6.1%, multivariable HR: 1.72, p < 0.001). Lack of information regarding earlier cancer controls, retreatment, tumor location within the kidney, and type of surgery represented limitations. Conclusions: In T1a RCC patients, LTD is invariably associated with higher CSM relative to PN, even after adjustment for OCM and all available patient and tumor characteristics, and regardless of tumor size considerations. However, the magnitude of CSM disadvan-tage was more pronounced in LTD patients with tumor size 3.1-4 cm than in those with tumor size < 3 cm. Patient summary: In patients with small renal masses, we observed higher cancer -specific death rates for local tumor destruction (LTD) than for partial nephrectomy. The LTD disadvantage was more pronounced for patients with tumor size 3.1-4 cm, but was also present in those with tumor size < 3 cm.