表在性膀胱癌に対するTUR-Bt後の定期的膀胱生検の病変検出率と臨床的意義

Abstract

TUR-Bt(経尿道的切除)を受けた表在性膀胱癌患者で再発リスクが高いと考えられる64例に対し定期的に膀胱粘膜ランダム生検を行った.その結果, 本生検による上皮内癌の検出率は, 今日一般的に行われている膀胱鏡+尿細胞診に比べて高いと考えられたが, 全ての残存病変を検出するには至らなかった

The role of the periodical bladder biopsy after transurethral resection (TUR-Bt) of superficial bladder cancer (sBT) was evaluated. Sixty-four patients (85 TURs) with sBT who underwent TUR-Bt between 1993 and 1998 were divided into 14 (22 TURs) who had carcinoma in situ (CIS) at the first TUR (group A), and 50 (64 TURs) who had papillary tumors without concomitant CIS (group B). Post-TUR intravesical instillation was performed with bacillus Calmette-Guerin for the majority of group A, and mitomycin C for the majority of group B. The first biopsy was performed at 3 months postoperatively, and the second biopsy was done at 8 to 12 months postoperatively. The mean observation time was 4 years and 6 months. Residual cancer was detected in 7 out of 34 biopsies (20.6%) in group A, and 19 out of 94 (20.2%) in group B. Every residual lesion in group A was CIS with negative cytology. In group B, with exclusion of 11 recurrent papillary tumors, the detection rate was only 8/83 (9.6%). In both groups, even in the cases with no sign of disease in biopsies, the recurrence immediately after the termination of the biopsy protocol was common. The progression of the cancer was more frequent in group A (4 patients), than in group B (2 patients) (p < 0.01, log-rank test), and no case in group B showed local progression. The periodical biopsy may have a certain, but limited advantage over conventional examinations. A less invasive and more sensitive method in awaited.