[Detection of bladder cancer in voided urine samples]

Bladder cancer mainly affects patients aged 50 years or more and requires close and repeated surveillance. Flexible cystoscopy associated with urinary cytology are the currently recommended diagnostic and follow-up methods. Because medical imaging techniques remain rather unsatisfying for bladder carcinoma detection, research efforts have focused on urinary markers of the disease. Various approaches were tested with results generally too unconsistant to replace cystoscopy. Recently, the department of Urology at the University of Liège together with the Biotechnology Company OncoMethylome Sciences have been interested in testing whether the detection of hypermethylated genes in voided urine samples would be of value for the detection of bladder cancer. The method is based on the Methylation-Specific PCR technology (MSP). This approach has the theoretical advantage of being non invasive, reproducible and based on DNA, whose stability, in urine, is higher than that of proteins. The results of a large prospective study, recently publised in European Urology, have shown that the identification by MSP of 2 methylated genes, TWIST1 and NID2, in voided urine samples, is a sensitive (+/- 90%) and specific (+/- 93%) test for the detection of bladder cancer. The test is largely more sensitive than cytology while both techniques have similar specificity. Based on these promising results, we are currently evaluating this novel, non invasive MSP approach for the follow-up of patients with non-muscle invasive bladder cancer.