Correlation between biopsy and radical cystectomy in assessing grade and depth of invasion in bladder urothelial carcinoma

Abstract

Objectives. To assess the degree of correlation between the pathologic characteristics of the specimens obtained from biopsy and radical cystoprostatectomy. The stage and grade of bladder urothelial (transitional cell) carcinoma are important predictors of prognosis. Methods. We retrospectively identified 169 cases of urothelial carcinoma from 222 radical cystectomies performed at University of Chicago Hospitals from 1992 to 1999. Results. For all the cases in this study, the histologic grade, using the 1998 World Health Organization and International Society of Urological Pathologists (WHO/ISUP) classification, was identical when the biopsy specimen and radical cystectomy specimen were compared. However, when the same cases were assessed using the traditional three-grade system, the histologic grade increased or decreased by one grade in 19 (11%) and 8 (5%) of 169 cases, respectively. Patients with invasion of the lamina propria on biopsy had tumor extending outside the bladder in 15 (27%) of 55 cases. Patients with invasion of the muscularis propria on biopsy had tumor extending outside the bladder in 47 (49%) of 96 cases, including nodal metastasis in 22 (23%) of 96 cases. Overall, bladder biopsy underestimated the true extent of the disease in 78 (46%) of 169 cases. Conclusions. Using either the WHO/ISUP (1998) classification or the traditional three-grade system, the histologic grade of the biopsy specimen is a fairly good predictor of the final histologic grade. The preoperative biopsy tends to understage bladder cancer. Patients with muscularis propria invasion demonstrated by biopsy have a significantly higher risk of non-organ-confined disease than those with lamina propria invasion.