Tyrosine-kinase inhibitors in the treatment of muscle invasive bladder cancer and hormone refractory prostate cancer.

ABSTRACT

OBJECTIVES: Various protein kinases are known to be activated in cancer cells and drive tumor growth and progression. In metastatic renal cell carcinoma tyrosine-kinase inhibitors (TKIs) have achieved significant progression-free and overall survival improvements. For bladder and prostate cancers TKIs may also be considered as a promising treatment option. Our aim was to report the most relevant published articles to support the interest of the use of TKIs in the treatment of bladder and prostate cancer. METHOD: PubMed database and bibliographies of retrieved articles were reviewed. The key words used were tyrosine-kinase inhibitor, protein-kinase inhibitor, hormone refractory prostate cancer, muscle invasive bladder cancer. The most relevant publications from basic science and clinical randomized controlled studies were summarized and analyzed. RESULTS: Regarding bladder cancer, TKI treatment is one of the most studied therapeutic strategies in the field of targeted therapy. Indeed, it has been suggested that targeting TK alone and/or in association with cytotoxic chemotherapy may represent a promising option for treating locally advanced and/or metastatic bladder cancer. Concerning hormone refractory prostate cancer (HRPC), collected data are still confusing. Basic science studies found an interesting expression of EGF and VEGF receptors on cancer cells supporting the idea that TKIs could be efficient in HRPC. Nonetheless most of published clinical phase II studies found a weak effect on symptoms and quality of life without any decrease in PSA levels or overall survival. CONCLUSION: TKIs have not yet achieved in bladder and prostate cancers similar efficacy to what has been obtained in metastatic renal cell carcinoma. Further studies are needed to establish the place of such an approach in non renal tumors.