ImmunoCyt and cytokeratin 20 immunocytochemistry as adjunct markers for urine cytologic detection of bladder cancer: a prospective study.

OBJECTIVE

To determine whether ImmunoCyt (uCyt+) immunofluorescence and cytokeratin 20 (CK20) immunocytochemistry add additional diagnostic value in the detection of urothelial carcinoma (UC) in samples of urine liquid-based cytology (LBC).

STUDY DESIGN

We prospectively collected voided urine samples from a total of 169 in-house patients with a variety of urologic conditions. Voided urine samples from 22 healthy individuals who came to the clinic as part of a routine annual physical examination were also collected as negative controls. Urine LBC, uCyt+ immunofluorescence and CK20 immunocytochemistry were performed on the specimen, and all 3 tests were evaluated independently in a blinded fashion. Cystoscopy with histologic diagnosis was used as the gold standard for diagnosis.

RESULTS

Of 169 inpatients, 135 cases had histologic diagnoses, including 93 cases of UC with primary tumors in 68 and recurrent tumors in 25, 26 cases of other urologic malignancies and 16 cases of benign urologic lesions. Comparing to LBC, both uCyt+ and CK20 had a significant increase in the sensitivity of detecting UC (from 49.4% for cytology to 81.6% and 77.0% for uCyt+ and CK20, respectively, p < 0.0001 for both by chi2 test). The specificity, in contrast, did not show significant change (from 91.1% for LBC, to 86.7% for uCyt+ and 91.1% for CK20, p > 0.05).

CONCLUSION

Both uCyt+ and CK20 performed on LBC samples showed an improvement in the sensitivity of cytology in detecting UC, especially for low grade UC, without a significant decrease in specificity. These tests provide useful adjunct markers for cytologic detection of UC.