Effectiveness of a single immediate mitomycin C instillation in patients with low risk superficial bladder cancer: short and long-term follow-up.
We analyzed the impact of a single Mitomycin C instillation in patients with low risk superficial bladder cancer with short and long-term follow-up. This study was conducted on 63 patients with low risk superficial bladder transitional cell carcinoma (TCC), admitted to the Urology Department, Theodor Bilharz Research Institute (TBRI) during the period from January 2002 to August 2005. All patients had a 2 cm. or less single, papillary, primary or recurrent tumor and were disease-free for more than 1 year. Patients with muscular invasion, G III tumor or bladder carcinoma in situ on pathological examination were excluded from the study. The tumor was completely resected before patients were divided randomly into 2 arms: first group who have received no further treatment (control group) and a second group with a single immediate instillation of 30 mg. Mitomycin C (mitomycin C group). Recurrences were considered early if they occurred within the first 2 years of follow-up. At 24-months follow-up, the recurrence-free interval was significantly increased and recurrence, recurrence per year and tumor per year rates were decreased in the mitomycin C group compared to the control group. Early recurrence was (16.1%) in the mitomycin C group versus (34.3%) in the control group. It was noted also that early recurrences were concentrated in the first year in the control group (18.7%) versus (3.2%) in the mitomycin C group. However, at long-term follow-up, these differences were not statistically significant (26.9%) in the mitomycin C group versus (28.6%) in the control group, and the recurrence-free interval curves were parallel. A significant relationship between early and late recurrences was found in the mitomycin C, but not in the control group. Shorter hospital stay and catheterization periods were noted in the mitomycin C group compared to the control group, but the differences were not statistically significant. These data confirm the positive effect of a single immediate mitomycin C instillation in patients with low risk superficial bladder cancer. This benefit is limited to early recurrence and is not maintained with long-term follow-up. Thus, this approach is an alternative to observation or classic long-term intravesical chemotherapy. Our study also suggests that cell implantation as a mechanism of early recurrence can be controlled or minimized with a single mitomycin C instillation.