[Sporadic bilateral kidney tumour: practical approach and place of conservative surgery]

To study the specific features of the sporadic form of bilateral renal cell carcinoma (RCC).

Twenty-six patients presented bilateral RCC among a total of 759 patients operated for RCC in our institution between 1985 and 1998. The mean follow-up for 23 patients (3 were lost to follow-up) was 56.5 months. Actuarial survival was estimated by the Kaplan-Meier method and comparisons between the various groups were performed with a Mann-Whitney test.

This series comprised 10 asynchronous tumours and 16 synchronous tumours. The mean diameter of synchronous tumours was significantly greater than that of asynchronous tumours (61 vs 33.5 mm). Histology revealed 16 clear cell carcinomas (CCC), 7 tubulopapillary carcinomas (TPC), 2 cases with CCC and TPC, and one bilateral oncocytoma. Malignant tumours were classified as stage T1-T2 (n=23) or T3 (n=2). TPC was more frequently bilateral than CCC (7.9% vs. 2.8%). Forty-four surgical operations (19 radical nephrectomies and 24 partial nephrectomies) were performed. The mean interval between two operations for asynchronous tumours was 85.2 months. Follow-up demonstrated 15 remissions and 6 deaths, including 5 deaths due to RCC, one local recurrence and one local recurrence with metastases. One-year specific survival was 96% and 5-year survival was 74%. Age, gender, histological type and the asynchronous or synchronous mode did not induce any significant difference on survival.

The surgical approach must therefore be resolutely conservative in view of the good 5-year survival rate and the low local recurrence and metastasis rates.