[Circumstances of the detection of kidney cancer. Current part of accidental discoveries].

Kidney cancer accounts for 3% of all cancers, with approximately 85% of tumors arising in the renal parenchyma (renal cell carcinoma). To evaluate the part of the incidental detection of the renal carcinoma, we performed a retrospective review of the 302 patients treated for this reason in our department between April 1981 and October 1992. For the purpose of a historical comparison, 2 periods of 6 years were compared: 1981-1986 and 1987-1992. During 1981 to 1992, 71 patients (25.8%) were totally asymptomatic, with a significant improvement of the incidentally detected tumors from 1981-1986 (15%) to 1987-1992 (33.7%) (p < 0.001). Renal ultrasonography, which is responsible for 97% of the incidental diagnosis, allow for a better detection in the right kidney (60.3% vs. 39.7% in the left kidney) (p < 0.05). Primary tumor size and clinical stage (with Robson or the TNM 1992 classification) were significantly smaller (47.3 +/- 19.9 mm for the asymptomatic group vs. 71.6 +/- 34.1 mm for the symptomatic tumors) and lower respectively, in the asymptomatic group than in the symptomatic group (p < 0.001). The five-year survival rate (actuarial method) of the incidental cases tended to the better for the asymptomatic cases (87.5% vs. 39% for the symptomatic tumors) (p < 0.05). Most of the authors agree that incidental diagnosis has led to lower tumor size and stage and possibly better survival rate compared to cases where the diagnosis was suspected clinically. However, prospective studies on a large scale are needed to evaluate the role of nephron sparing surgery for incidental cancer of the kidney. Nowadays, the treatment remains radical nephectomy.(ABSTRACT TRUNCATED AT 250 WORDS)