長期間再発を認めなかった筋層非浸潤膀胱癌の経過観察方法

Abstract

To determine the follow-up schedule in patients with non-muscle-invasive bladder cancer who had remained recurrence-free for 5 or more years, we retrospectively reviewed 258 patients with Ta and T1 bladder cancer who had been free of recurrence for at least 5 years. Of these 258 patients, subsequent recurrences developed in 100 patients. In spite of our recommendation that cystoscopic follow-up be done at 12-month intervals for patients who remained recurrence-free for more than 5 years, 45 had been followed at intervals of more than 12 months (range, 13-77 months) when the recurrences were found. Of 100 recurrent tumors, 20 (20.0%) showed bladder muscle invasion. Muscle-invasive cancer was identified more often in the patients with cytoscopic intervals of more than 12 months than in those of less than 12 months (35.6% versus 7.3%). Therefore, we recommend that cystoscopy be performed at intervals of less than 12 months in patients with non-muscle invasive bladder cancer for recurrence detection before tumors become muscle invasive, even when patients remain free of recurrence for a long period.