An overview on preclinical and clinical experiences with photodynamic therapy for bladder cancer

Photodynamic therapy (PDT) is one of the most interesting methods of photo treatment. In general, PDT is a modality for the treatment of non-muscle invasive tumors. PDT is very well suited in managing bladder cancer, as the bladder is accessible by endoscopy and the tumors are most often limited to the mucosa or sub-mucosa. PDT is likely more useful for patients with recurrent tumors after conventional therapies, as well as for patients with diffuse non-muscle invasive bladder carcinomas that are refractory to standard treatments before the commitment to radical extirpative surgery, particularly in patients at surgical high risk. The treatment of tumors with PDT includes three major parameters: presence of oxygen in tumor tissue, administration of a photosensitizer, and subsequent exposure to light. The PDT mechanism relies on the in situ generation of cytotoxic agents by the activation of a light-sensitive drug, resulting in cell death. In this review, we present past and current advances in the use of PDT with urinary bladder cancer and discuss the future roles for this type of therapy in the treatment of bladder cancer.