[Value of urinary microsatellite analysis in the diagnosis of renal cancer]

To detect the presence of tumour DNA in urine of patients with renal cancer based on microsatellite analysis.

Blinded, comparative, experimental study conducted between July 1996 and December 2003. Preoperative urine and blood samples were collected from 69 patients with renal cancer (pT1 to pT4). The control population comprised 35 patients with a benign urological disease. Loss of heterozygosity (LOH) and allele amplification were investigated by analysing allele imbalances between urinary DNA and blood lymphocyte DNA. Twenty-six loci were analysed, including 23 microsatellites. We studied the sensitivity and specificity of this analysis as a function of stage, grade and invasion of renal cavities by the tumour.

The sensitivity of the test was 61% for pT1a and the global sensitivity was 62.3%. A significant difference was observed in favour of low nuclear grades (p < 0.05). More than 80% of tumours detected were identified by 4 microsatellites. The specificity was 83%. Renal cavities were invaded by the tumour in 38% of cases. No correlation was observed between invasion of renal cavities and the result of the test.

The results are encouraging, particularly for small tumours and justify development of clinical applications.