ERBB2 and urothelial carcinoma: Additionally, the distribution of histological subtypes differed significantly among the three HER2 groups (<i>P</i> = 0.024), with the proportion of conventional urothelial carcinoma being the highest in the HER2 0/1+ group (86.6%).<h4>Conclusions</h4>IPCa is not uncommon in patients undergoing radical cystectomy.