The impact of time to local tumor destruction on cancer-specific mortality in pT1a renal cell carcinoma

Objective: To evaluate the impact of time to local tumor destruction > 6 months on cancer-specific mortality in patients with pT1a renal cell carcinoma. Methods: Using the Surveillance, Epidemiology, and End Results database (2004–2022), patients with pT1aN0M0 renal cell carcinoma of 1–3 cm treated with local tumor destruction were stratified according to time to local tumor destruction (⩽ 6 vs > 6 months). Propensity score matching and multivariate competing risks regression were used. Sample power analyses were performed. Results: Among 3528 pT1a 1–3 cm renal cell carcinoma patients, time to local tumor destruction > 6 months was recorded in 282 (8.0%) patients. After propensity score matching, patients with time to local tumor destruction > 6 months demonstrated a 60-month cancer-specific mortality rate of 10.0% versus 4.6% in patients with time to local tumor destruction ⩽ 6 months. In multivariable competing risks regression models, statistical significance was not achieved (95% confidence interval: 0.8–2.8, p = 0.24). Power analysis revealed a power of 28%. To achieve 80% power with the observed cancer-specific mortality rates, 1450 patients per arm would be required. Conclusions: Although time to local tumor destruction > 6 months is associated with a 5.4% cancer-specific mortality increase, the present study was underpowered to identify a benefit to early treatment with local tumor destruction. In the absence of better data, a 6-month delay is acceptable when considering local tumor destruction. Level of Evidence: 3.