Diagnostic accuracy of intraoperative frozen sections during radical cystectomy does not affect disease-free or overall survival: a study of 364 patients with urothelial carcinoma of the urinary bladder

The utility of intraoperative frozen sections for determining ureteral and urethral margin status is controversial. In this study, we evaluated the sensitivity and specificity of frozen section diagnosis with the corresponding final tissue diagnosis in a series of 364 patients undergoing radical cystectomy for urothelial carcinoma of the urinary bladder. Multiple definitions of a positive diagnosis were analyzed. We then used clinical follow-up data to determine the effect of various frozen section diagnoses, frozen/permanent section discordance, and surgical margins on overall survival and disease-free survival. Increasing severity of dysplasia was associated with corresponding increases in positive likelihood ratio, with carcinoma displaying the highest positive likelihood ratio (211.43) for an accurate frozen section diagnosis. A diagnosis of carcinoma on frozen section did not affect overall or disease-free survival nor did a positive surgical margin. Frozen/permanent discordance did not show significant associations with overall survival or disease-free survival. The lone variable approaching statistical significance was an association between frozen/permanent discordance of ureteral samples and disease-free survival (hazard ratio, 3.23; P = .07; multivariate Cox proportional hazards model). The results of this study, the first to evaluate the use of different cutoffs for a positive diagnosis and the effects of frozen/permanent discordance, do not support the routine use of intraoperative frozen section during radical cystectomy for urothelial carcinoma. However, subgroups at high risk for positive ureteral margins may benefit from intraoperative frozen section evaluation.