A multicenter comparative matched-pair analysis of percutaneous tumor ablation and robotic-assisted partial nephrectomy of T1b renal cell carcinoma (AblatT1b study-UroCCR 80).

OBJECTIVE: Renal cell carcinomas represent the sixth- and tenth-most frequently diagnosed cancer in men and women. Recently, percutaneous-guided thermal ablations have proved to be as effective as partial nephrectomy and safer for treating small renal masses (i.e., < 3 cm). This study compared the perioperative and recurrence outcomes of percutaneous thermal ablation (TA) and robotic-assisted partial nephrectomy (RAPN) for the treatment of T1b renal cell carcinomas (4.1-7 cm). METHODS: Retrospective data from 11 centers on the national database, between 2010 and 2020, included 81 patients treated with thermal ablation (TA) and 308 patients treated with RAPN for T1b renal cell carcinoma, collected retrospectively and matched for tumor size, histology results, and the RENAL score. TA included cryoablation and microwave ablation. Endpoints compared the rate between the two groups: local recurrence, metastases, complications, renal function decrease, and length of hospitalization. RESULTS: After matching, 75 patients were included in each group; mean age was 76.6 (± 9) in the TA group and 61.1 (± 12) in the RAPN group, including 69.3% and 76% men respectively. The local recurrence (LR) rate was significantly higher in the TA group than in the PN group (14.6% vs 4%; p = 0.02). The LR rate was 20% (1/5) after microwave ablation, 11.1% (1/9) after radiofrequency ablation, and 14.7% (9/61) after cryoablation. The major complication rate (Clavien-Dindo ≥ 3) was higher following PN than after TA (5.3% vs 0%; p < 0.001). Metastases, eGFR decrease, and length of hospitalization did not differ significantly between the two groups. CONCLUSIONS: The local recurrence rate was significantly higher after thermal ablation; however, thermal ablation resulted in significantly lower rates of complications. Thermal ablation and robotic-assisted partial nephrectomy are effective treatments for T1b renal cancer; however, the local recurrence rate was higher after thermal ablation. KEY POINTS: • The local recurrence rate was significantly higher in the thermal ablation group than in the partial nephrectomy group. • The major complication rate (Clavien-Dindo ≥ 3) was higher following PN than after TA (5.3% vs. 0%; p < 0.001).