Immunocytochemically demonstrated expression of epithelial membrane antigen and carcinoembryonic antigen by exfoliated urinary cells in patients with bladder cancer.

The localization of epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA) in exfoliated cells from voided urine was examined to clarify whether immunostaining for these markers is more useful than conventional cytology for diagnosis of patients with transitional cell carcinoma of the bladder. Both EMA and CEA were present more frequently in specimens from higher-grade and higher-stage tumors than lower-grade and lower-stage tumors. Cells positive for one or both of these markers were also found in specimens from cancer patients with only suspicious results by conventional cytology. In grade 1 tumors, the positive rates were 50% for EMA staining and 40% for CEA staining compared with 10% for conventional cytology. In 12 patients with cystitis, results for EMA staining and conventional cytology were all negative, whereas CEA staining proved positive in 6 patients (50%). None of 10 normal subjects with conventional cytology had positive results for EMA or CEA staining. These findings indicate that immunocytochemistry for EMA is a more useful adjunctive method than CEA staining or conventional cytology for detection of tumor cells, especially in cases of low-grade bladder cancer.