Detection of bladder cancer using voided urine sample and by targeting genomic VPAC receptors

Cells exfoliated into urine from the bladder can help to diagnose the cancer. The objective of this study was to validate the hypothesis that bladder cancer could be detected noninvasively by a simple and reliable assay targeting genomic VPAC (combined vasoactive intestinal peptide and pituitary adenylate cyclase-activating peptide family of cell surface receptors) receptors expressed on the malignant bladder cancer cells shed in the voided urine.

Patients ≥18 years of age with either imaging (ultrasonography/computed tomography [CT])-confirmed bladder tumors or those who have been previously treated for nonmuscle invasive bladder tumors and were visiting the department for check cystoscopy, formed the study group. Freshly voided urine sample was collected from these patients and sent for conventional cytology examination, 5-aminolevulinic acid (ALA) fluorescent urine cytology, and for positivity of VPAC receptors.

A total of 103 patients were prospectively included in the study. Of these, 65 patients (Group I) presented with image-diagnosed (ultrasonography and/or CT) bladder cancer. The remaining 38 patients (Group II) were previously diagnosed cases of nonmuscle invasive bladder cancer and presented for follow-up and check cystoscopy. The sensitivity for VPAC receptor positivity was 89.23% compared to conventional cytology (63.07%) and 5-ALA fluorescent urine cytology (87.69%). The specificity of VPAC receptor positivity was 100% compared to conventional cytology (100%) and 5-ALA-induced fluorescent cytology (90.47%).

Our preliminary study shows encouraging results with VPAC receptor positivity studies, which has a high sensitivity when compared to the conventional cytology.