Utility of urothelial mRNA markers in blood for staging and monitoring bladder cancer.

OBJECTIVE

To test the efficiency of 6 mRNA bladder markers in staging urothelial cell carcinoma (UCC) and monitoring UCC dissemination from blood samples.

METHODS

From 2002 to 2009, 347 blood samples were collected from 150 patients with UCC and 29 healthy controls. Sequential blood sampling was performed in patients undergoing cystectomy at surgery and 6, 12, 18, and 24 months postoperatively. The median follow-up was 33 months. The presence of KRT20, FXYD3, C10orf116, UPK2, AGR2, and KRT19 markers in blood was evaluated in all patients and controls by measuring the gene expression using preamplified cDNA and reverse transcriptase quantitative polymerase chain reaction. Gene expression data were correlated with the tumor risk, follow-up, and outcomes data.

RESULTS

Expression of C10orf116 and KRT19 genes differed between patients and controls (P<.001). KRT20, C10orf116, and AGR2 differentiated between low- and high-risk nonmuscle-invasive bladder cancer (P=.001, P=.011, and P=.001, respectively). FXYD3 differentiated between patients with high-risk nonmuscle-invasive bladder cancer and those with muscle-invasive bladder cancer (P=.009). In contrast, the 6 markers showed no differences in gene expression between metastatic and patients without metastases who had not undergone cystectomy (P=NS). None of the markers were significantly increased in the metastatic patients at 6, 12, 18, or 24 months after surgery.

CONCLUSION

The gene expression of bladder-specific mRNA markers in blood was different among the various tumor risk groups of patients with UCC. However, this gene expression analysis is not suitable for predicting metastases or monitoring UCC hematogenous dissemination in patients who have undergone cystectomy.