Topical chemoprophylaxis of superficial bladder cancer with mitomycin C and adjuvant hyaluronidase.

The effect of intravesical instillation of 200,000 IU hyaluronidase in addition to mitomycin C as chemoprophylaxis of superficial bladder cancer was evaluated. Based on our result of a previous study that this approach results in a significantly reduced recurrence rate (7.1 versus 32.1%), 43 patients undergoing transurethral resection of Ta-T1 tumors were retrospectively analyzed after a mean observation period of 48.5 months. During the 2 years of prophylactic therapy, tumor recurrence was seen in 6 patients (13.9%). Of the 37 patients who remained recurrence-free under treatment, 5 (13.5%) had recurrent tumors later during a mean observation period of 24.5 (18-42) months after treatment. These values are significantly lower than those obtained previously from a group of 63 patients treated with mitomycin alone, with recurrence rates of 33.3% during chemoprophylaxis and 26.2% thereafter (mean observation period 50.4 months). It appears that additive hyaluronidase enhances the local effect of mitomycin C in the intravesical chemoprophylaxis of bladder cancer, presumably by improving diffusion into the bladder mucosa and catalyzing the breakdown of a hyaluronic acid contained in a protective halo around malignant urothelial cells.