Comparing Oncologic Outcomes of Heat-Based Thermal Ablation and Cryoablation in Patients With T1a Renal Cell Carcinoma: A Population-Based Cohort Study From the SEER Database.

Abstract

Objective: There is controversy among different guidelines regarding the use of thermal ablation to treat clinical T1a renal cell carcinomas with tumor sizes ranging from 3.1-4 cm. Therefore, we compared oncological outcomes between heat-based thermal ablation (hTA) and cryoablation (CA) in patients with solid T1a renal cell carcinomas, including those with a tumor size ≤3 cm and a tumor size of 3.1-4 cm.

Materials and methods: Within the Surveillance, Epidemiology, and End Results database (2000-2019), we identified patients with clinical T1a renal cell carcinomas that were histologically confirmed and treated with hTA or CA. After propensity score matching using a 1:1 ratio, the overall survival (OS) and cancer-specific survival (CSS) were estimated and compared between the two methods. Cancer-specific mortality (CSM) was also analyzed, considering other-cause mortality as a competing risk.

Results: Of the 3513 assessable patients, 1426 (40.6%) and 2087 (59.4%) were treated with hTA and CA, respectively. After propensity score matching, the hTA and CA groups included 1393 and 1393 patients, respectively. hTA was associated with shorter OS than CA with a hazard ratio of 1.17 (95% confidence interval, 1.04-1.32; P = 0.010). The hTA and CA groups did not reveal statistically significant differences in CSS with a hazard ratio of 1.07 (95% confidence interval, 0.76-1.50; P = 0.706). The hTA and CA groups did not show statistically significant differences in CSM (P = 0.849). However, the hTA group showed a significantly higher other-cause mortality (P = 0.011).

Conclusion: In patients with clinical stage T1a renal cell carcinomas, hTA was comparable to CA in terms of CSS and CSM. However, hTA resulted in a slightly shorter OS than CA. Large-scale randomized clinical trials are required to obtain more robust evidence.