Laparoscopic cryoablation for small renal masses: Oncological outcomes at 5-year follow-up

Objective: To evaluate the oncological outcome at 5-year follow-up after laparoscopic cryoablation (LCA) for small renal masses (SRMs), as there is an increasing interest in ablative therapy for cT1a renal tumours due to the rising incidence of SRMs, the trend towards minimally invasive nephron-sparing treatments, and the ageing population. Patients and methods: Between 2004 and 2015, 233 consecutive LCA were performed in 219 patients for SRMs at two referral centres. We only included those patients with ≥5 years of follow-up (n = 165) in a prospectively maintained database. A descriptive analysis was conducted for pre-, peri- and postoperative characteristics. A Kaplan-Meier analysis assessed overall (OS), disease-specific (DSS), and recurrence-free survival (RFS). Results: The median (interquartile range [IQR]) age of our patient cohort was 68 (60.5-76) years. The median (IQR) body mass index was 26.2 (23.8-29) kg/m², and the median (IQR) Charlson Comorbidity Index score corrected for age was 4 (2.5-6). The median (IQR) tumour diameter was 28 (21-33) mm. In all, 15% developed a complication in the first 30 days after LCA, of which 1% had a major complication (Clavien-Dindo Grade ≥III). The median (IQR) preoperative estimated glomerular filtration rate (eGFR) was 82.5 (65-93.75) mL/min/1.73 m². The median eGFR decreased by 16.4% and 15.2% at the 3-month and 5-year follow-up, respectively. Persistence was found in 1%, local recurrence in 2%, and systemic progression in 4%. The OS, DSS, and RFS were 74%, 96.9% and 95.4%, respectively. Conclusion: LCA is a safe and effective treatment for SRMs in selected cases and shows good oncological outcomes after 5 years of follow-up, with only 1% developing a major complication.