[Long-term follow-up of renal cell carcinomas T1a treated by percutaneous radiofrequency]

To evaluate the long-term oncological and functional results of the ablative treatment of T1a kidney malignancies by percutaneous radiofrequency (RF).

Monocentric retrospective study including all patients treated for renal cell carcinoma (RCC) T1a by radiofrequency, in our center, from 2005 to 2009. All patients had a tumor biopsy before treatment. The primary endpoint was local recurrence. A total of 44 RCCs in 41 consecutive patients were treated (1 patient had 3 synchronous tumors and 1 patient had 2 tumors). There were 26 clear cell RCCs, 13 papillary RCCs and 5 chromophobe RCCs. The median age at diagnosis was 70 years [48-82]. The median American Society of Anesthesiologists (ASA) score was 2 [1-3] and the median glomerular filtration rate (GFR) was 64mL/min [26-109]. Furhman grade was defined for 39 tumors (Clear cell RCC and papillary RCC), of which 82% were grade 1-2. The median tumor size was 20mm [11-40], and the median RENAL score was 4 [4-6]. Complications were assessed according to the Clavien-Dindo classification. Overall survival, recurrence-free survival and metastasis-free survival were calculated using the Kaplan-Meier method.

Median follow-up was 90.5 months [17.8-145.3]. Three (7%) local recurrences were reported within a median of 26 months [12-93]. All were treated by a 2nd RF. The overall 10-year survival was 70% (95% CI [56-85]). The 10-year recurrence-free survival was 72% (95% CI [57-88]). The 10-year metastasis-free survival was 87% (95% CI [74-97]). The median GFR on the date of the last news was 51mL/min [16-98] (P=0.05). Post-RFA complications consisted in 5 (11.3%) Clavien-Dindo 1-2 complications. No high grade (Clavien ≥3).

Percutaneous radiofrequency for RCC T1a is an alternative. It appears to be safe with low morbidity, satisfaying long-term oncological and functional results, but a risk of reprocessing of 7%.

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