Regional Therapy of Bladder Tumors

Abstract

The urinary bladder is an ideal organ for local topical treament. Numerous agents have been instilled intravesically during the last century to decrease bladder tumor recurrence and prevent progression and subsequent patient mortality. Today, intravesical immunotherapy with BCG and chemotherapy are routinely used as an adjunct to surgical resection of superficial bladder tumors. Photodynamic therapy with different photosensitizers and thermotherapy in combination with intravesical chemotherapy or percutaneous radiotherapy have been evaluated in phase III studies and may soon be widely available tools for the clinical treatment of bladder cancer. The first clinical phase I trials demonstrating safe application have been reported for intravesical gene therapy and antisense therapy approaches. Despite initial promising results of HIFU therapy and interventional radiotherapy, it cannot be anticipated that these two techniques will enter the clinical routine in the near future. Although the bladder is an easily accessible organ for regional treatment, a glycosaminoglycan (GAG) layer on the bladder mucosa can prevent the sufficient uptake and integration of many intravesically applied therapeutical compounds. Iontophoresis has shown clinical success in enhancing the uptake of, for instance, chemotherapeutic agents. Furthermore, magnetically targeted carriers, microspheres, and nanocarriers have been tested preclinically.