Significance of bladder biopsies in Ta,T1 bladder tumors: A report from the EORTC Genito-Urinary Tract Cancer Cooperative Group

Objectives: We investigated to what extent biopsies of normal-appearing uro thelium taken from patients with Ta,T1 bladder cancer showed malignant dise ase: carcinoma in situ, or papillary tumor. We also investigated biopsies u nderlying the papillary tumor, adjacent to the tumor, and from suspicious-a ppearing mucosa. Methods: In EORTC protocol 30863 (low-risk tumors), 393 pa tients underwent a biopsy of normal-appearing urothelium. In protocol 30911 (intermediate- and high-risk tumors), multiple biopsies were taken from no rmal-appearing urothelium in 602 patients. Results: No abnormalities were f ound in the random biopsies of 376 (95.6%) patients with low-risk tumors an d in 532 (88.4%) patients with intermediate- and high-risk tumors. Six (1.5 %) patients with low-risk tumors and at least 21 (3.5%) patients with highe r-risk tumors showed carcinoma in situ in their random biopsies. None of th e patients in the low-risk group and 1 (0.2%) patient in higher-risk group had an invasive tumor (greater than or equal to T2). Conclusions: This anal ysis indicates that biopsies of normal-appearing urothelium in Ta,T1 bladde r cancer patients show no abnormalities in about 90% of the patients. Perfo rming such biopsies does not contribute to the staging or to the choice of adjuvant therapy after transurethral resection.