From microarrays to new therapeutic approaches in bladder cancer

Bladder cancer is a model tumor progressing from superficial to locally invasive and finally metastatic disease. The likelihood of progression is determined to a large extent by the molecular profile of the tumor. From the pre-genomic era only p53 emerged as the molecular prognostic factor able to add value to existing clinical and pathological features of bladder cancer, however it was not introduced to the clinic. Microarray technologies enable us to study expression of thousands of genes in the tumor tissue. This method has already proven to add information to clinical classifiers, to find new tumor suppressor genes and to define p53 related pathways of cell-cycle regulation. In the last decade, progress in the treatment of locally invasive and metastatic bladder cancer was minimal; large Phase III trials with neo/adjuvant chemotherapy were inconclusive. The new paradigm of treatment tailored to an individual patient could be realized in bladder cancer for his chronic clinical course with opportunities to obtain tumor samples for microarray studies. Molecular profiling of two samples taken at the superficial stage and at cystectomy should enable us to study the microevolution of the tumor, to tailor existing treatment options, and to introduce new biologicals to the clinic.Introduction