BACILLUS-CALMETTE-GUERIN (BCG) IN THE TREATMENT OF SUPERFICIAL BLADDER-CANCER - DEVELOPMENT OF RESISTANCE TO BCG AND STRATEGIES FOR OVERCOMING RESISTANCE TO BCG (REVIEW)

Intravesical therapy is currently being used in the management of supe rficial transitional cell carcinoma of the urinary bladder. Its main o bjectives constitute treatment of existing or residual tumor, preventi on of recurrence of tumor, prevention of disease progression, and prol ongation of survival. The initial clinical stage and grade of bladder cancer remains the main determinant factors in survival, irrespective of the treatment. Intravesical chemotherapy has shown a decrease in sh ort-term tumor recurrence rates, but has had no positive impact on dis ease progression or prolongation of survival. Bacillus Calmette-Guerin (BCG) immunotherapy remains the most effective treatment and prophyla xis modality for superficial bladder cancer and results in a positive outcome on tumor recurrence, disease progression, and prolongation of survival. Although therapy by intravesical BCG instillation is widely accepted as the therapy of choice, the development of BCG-resistant bl adder cancer remains a major setback. Thus, there is an urgent need fo r a major effective therapy for bladder cancer patients who are unresp onsive to BCG therapy. This review summarizes briefly the recent highl ights and advances in the therapy of superficial bladder cancer. This review also describes our preliminary findings achieved in in vitro mo del systems and our proposed new approaches to overcome the resistance of bladder cancer cells and render bladder cancer cells responsive to these new therapies.