Adenoviral-Mediated Anti-H-ras Ribozyme for the Treatment of Bladder Cancer

Bladder cancer is the fifth most common malignancy, demonstrated by the approx 52,900 patients that will be diagnosed in the United States in 1996 (1 ). Around 15–20% of these patients will be characterized by muscle invasion or node posmve disease The standard therapy for muscle invasive disease is radical cystectomy, but the risk of subsequent development of metastatic diseases is seen in a high proportion of patients (60%). Also, the efficacy of pertoperative chemotherapy or irradiation for reducing the risk of developing metastatic disease is not well defined. Presently, only 15–20% of patients with metastatic bladder cancer can be cured. Novel approaches are urgently required for a treatment of invasive bladder cancer, and for the prevention or treatment of subsequent metastases A biologically based approach designed to reverse the invasive and/or metastatic phenotype may be more effective than chemotherapy. Recently, new molecular-based antioncogene strategies, such as antisense oligonucleotides (2 ,3 ) and ribozymes (4 ,5 ), have been studied for the treatment of bladder cancer.