A chemosensitivity test to individualize intravesical treatment for non-muscle-invasive bladder cancer.

Abstract

To describe the design of a new chemosensitivity assay based on the expression of genes involved in the resistance to standard intravesical regimens, to allow individualization of therapy for high-risk non-muscle-invasive bladder cancer. To date, 35 patients with high-risk non-muscle-invasive bladder cancer have been enrolled, all candidates for transurethral resection of the bladder (TURB) followed by intravesical treatment. The intravesical regimen was chosen according to the risk profile of each patient. All patients were evaluated by cystoscopy 3 and 6 months after TURB. According to the molecular characterization of each tumour, our team of molecular oncologists determined for each patient a molecular profile of chemosensitivity to BCG, mitomycin c, anthracyclines and gemcitabine. This profile was then correlated to the response to intravesical therapy 6 months after TURB. This chemosensitivity test was able to predict response to treatment in 96% of patients. The assay is easy to perform, inexpensive and quick. Our results, although preliminary, are encouraging for the future of an individualized therapeutic approach, with the aim to provide a higher treatment success rate while sparing patients unnecessary toxicity from drugs that are not suited for their tumours.