Study on expression of cytokeratin 20 mRNA in urine exfoliated cells from patients with bladder carcinoma

Objective To study whether cytokeratin 20(CK20) mRNA expression could be used as a bladder tumor marker for transitional cell carcinoma. Methods RT/PCR for testing CK20 mRNA was done with exfoliated cells isolated from 84 hematuria patients urine samples. The parameters were tumor grade, tumor size, number of tumors, urinary cytology and CK20 mRNA expression. Results In the urine samples of 22 bladder cancer patients, 18 expressed CK20 mRNA marker. Four false negative results were found. Among 62 patients without bladder cancer, two false positive results were found. Comparing CK20 mRNA marker tested by RT/PCR with urinary cytology, the specificity and positive predictive value of former were much higher (96.8% versus 77.4%, 90% versus 51.7% respectively, U value 3.21 and 2.81, P 0.01). There was no correlation between CK20 mRNA and tumor grade. Conclusion Our results indicate that CK20 mRNA by RT/PCR assay is a potential biomarker for noninvasive detection of bladder carcinoma. The CK20 mRNA marker was significantly more sensitive than urinary cytology.