The efficacy of mitomycin C, as with all intravesical therapies, depends on when and how it is given, as well as to whom it is given. Mitomycin C was initially given to patients who failed to respond adequately to BCG. Many of these patients did respond to mitomycin C, thus delaying or preventing the need for bladder removal surgery.
Many urologists now give mitomycin C immediately after TURBT in any patient who is at high risk for tumor recurrence. Its use in this setting has been found to reduce the frequency of tumor recurrence by 20% to 40%. It is especially effective in preventing early recur-rence or those that occur in the first year. When a tumor is resected, cells are dislodged from the main body of the tumor.
These cells swirl around in the bladder during the procedure and could potentially implant in other areas of the bladder, leading to recurrent tumors several months later. It is thought that giving a dose of mitomycin C as soon as the TURBT is complete can help kill the free cancer cells in the bladder, thereby preventing them from implanting and growing into recurrences.