CEA (CEACAM5) expression is common in muscle‐invasive urothelial carcinoma of the bladder but unrelated to the disease course

Abstract Objectives Carcinoembryonic antigen (CEA) is a cell surface glycoprotein that represents a promising therapeutic target. Serum measurement of shedded CEA can be utilized for monitoring of cancer patients. Material and Methods To evaluate the potential clinical significance of CEA expression in urothelial bladder neoplasms, CEA was analysed by immunohistochemistry in more than 2500 urothelial bladder carcinomas in a tissue microarray format. Results CEA staining was largely absent in normal urothelial cells but was observed in 30.4% of urothelial bladder carcinomas including 406 (16.7%) with weak, 140 (5.8%) with moderate, and 192 (7.9%) with strong staining. CEA positivity occurred in 10.9% of 411 pTaG2 low‐grade, 32.0% of 178 pTaG2 high‐grade, and 43.0% of 93 pTaG3 tumours (p 0.25). Conclusion CEA increases markedly with grade progression in pTa tumours, and expression occurs in a significant fraction of pT2–4 urothelial bladder carcinomas. The high rate of CEA positivity in pT2–4 carcinomas offers the opportunity of using CEA serum measurement for monitoring the clinical course of these cancers. Moreover, CEA positive urothelial carcinomas are candidates for a treatment by targeted anti‐CEA drugs.