Cryoablation for cT1b Renal Tumors? Yet To Be Determined

Abstract

Cryoablation (CA) has emerged as a thermal ablative alternative to nephron-sparing surgery predominately for high-risk patients with a clinical T1a renal mass suspected to be renal cell carcinoma (RCC) or those refusing surgery [1,2]. In this issue of European Urology, Caputo and colleagues [3] report on a matched comparative analysis between CA and robot-assisted partial nephrectomy (PN) for clinical T1b renal tumors. In brief, this retrospective study compared 31 cT1b renal tumors treated with either laparoscopic or percutaneous CA to 31 PN patients matched 1:1 for some baseline parameters. After matching for age, gender, tumor size, RENAL nephrometry score, body mass index, Charlson comorbidity index, American Society of Anesthesiologists score, preoperative serum creatinine, preoperative estimated glomerular filtration rate, and solitary kidney, there was no significant difference between the CA and PN groups in these baseline variables. In a shortterm follow-up with survival analyses being limited to those diagnosed with RCC (further limiting the subsets to 22 and 28 patients in CA and PN groups, respectively), the authors found a higher but not significantly different postoperative complication rate for the PN group, a significantly higher local recurrence rate for the CA group, and similar overall and cancer-specific survival. They concluded that patients treated with CA for cT1b renal tumors had a significantly higher rate of local cancer recurrence at 1 yr compared to those treated with PN. There is no level 1 evidence reported on the oncologic and functional outcomes of CA in comparison to PN. Therefore, evidence is drawn from retrospective studies and meta-analyses with the inherent limitations of selection bias, which in these cases can be quite significant yet unmeasured. The choice of treatment modality has been left to the discretion of the treating physician and the ensuing