Comparative Outcomes from Percutaneous Cryoablation and Partial Nephrectomy for T1b Renal Cell Carcinoma: A Surveillance, Epidemiology and End Results (SEER) Database Analysis

The 2024 National Comprehensive Cancer Network renal cancer treatment guidelines expanded the application of percutaneous cryoablation to include stage T1b lesions {1}. However, a lack of specific literature/selection criteria has hindered wider clinical adoption as an alternative to conventional surgery. The purpose of this investigation is to characterize outcomes of elderly patients with T1b Renal Cell Carcinoma (RCC) treated with percutaneous cryoablation (CA) vs partial nephrectomy (PN). 

 

Materials and Methods:

The SEER national cancer registry was queried to identify patients 65 years-old or older diagnosed with primary malignant RCC between 2010-2020. Only T1b lesions were included; patients with nodal or distant metastatic disease were not included. Patients were divided by treatment type into CA and PN sub-groups. Pearson’s chi-square test was employed to compare sub-group descriptive characteristics. Univariate Kaplan-Meier analysis was conducted to compare overall survival time (OS) and cause-specific survival time (CSS) between CA and PN. Multivariate cox-regression analysis was subsequently performed comparing overall and cause-specific mortality risk between treatment groups after adjusting for numerous demographic and tumor characteristic co-variables including age, sex, race, marital status, histology (ICD-O-3) and laterality.

Results: 359 patients met inclusion criteria for this retrospective analysis. 106 were treated with CA and 253 with PN. Mean cohort age was 73.064 years old with a mean follow-up time of 48.18 months. Univariate OS significantly differed (p < .001) with a mean of 82.970 months (SE 6.071) for the CA sub-group and 109.656 months (SE 3.098) for the PN sub-group. Univariate CSS did not significantly differ between sub-groups (p =.053). Multivariate cox-regression analysis demonstrated no significant difference in overall (HR, 1.512; 95% CI, 0.778-2.939; p=.222) or cause-specific mortality risk (HR, 1.742; 95% CI, 0.547-5.550; p =.348) between CA and PN.

Conclusion: In elderly patients with T1b RCC, there is no significant difference in overall or cause-specific mortality risk between those treated with CA vs PN. Differences in OS did not persist on multivariate analysis suggesting that these differences were not intrinsic to the type of intervention. This study provides valuable insight about the relative efficacy of minimally invasive cryoablation compared to surgery for T1b renal lesions. This is a particularly relevant and important clinical consideration for elderly patients who are often higher risk surgical candidates.