Effectiveness of a single immediate mitomycin C instillation in patients with low risk superficial bladder cancer: Short and long-term followup

Purpose: We analyze the impact of a single mitomycin C instillation in pati ents with low risk superficial bladder cancer with short and long-term foll owup. Materials and Methods: A total of 131 patients with low risk superficial bl adder cancer were included in a prospective randomized controlled trial. Al l patients had a 3 cm, or less single, papillary, primary or recurrent tumo r and were disease-free for more than 1 year. Patients with muscular invasi on, G3 tumor or bladder carcinoma in situ on pathological examination were excluded from study. The tumor was completely resected before patients were randomized into 2 arms of no further treatment (control group) and a singl e immediate instillation of 30 mg. mitomycin C (mitomycin C group). Recurre nces were considered early within the first 2 years of followup. Results: At 24-month followup the recurrence-free interval was significantl y increased, and recurrence, and recurrence and tumor per year rates were d ecreased in the mitomycin C compared to the control group. However, at long -term followup these differences were not statistically significant and the recurrence-free interval curves were parallel. A shorter hospital stay and catheterization period were noted in the mitomycin C group compared to the control group, which were not significant. Early recurrences were concentr ated in the first year in the control but not in the mitomycin C group. A s ignificant relationship between early and late recurrences was found in the mitomycin C but not in the control group. Conclusions: Our analysis confirms the positive effect of a single immediat e mitomycin C instillation in patients with low risk superficial bladder ca ncer. This benefit is limited to early recurrence and is not maintained wit h long-term followup. Thus, this approach is an alternative to observation or endovesical chemotherapy. Our study also suggests that cell implantation as a mechanism of early recurrence can be controlled with a single mitomyc in C instillation.