Expression of Membranous CD155 Is Associated with Aggressive Phenotypes and a Poor Prognosis in Patients with Bladder Cancer

SIMPLE SUMMARY: The presence of the poliovirus receptor (known as cluster of differentiation 155 (CD155)) in human cancer is an unfavorable prognostic marker. We investigated whether CD155 expression, divided into membranous and cytoplasmic types, affects the prognosis of bladder cancer (BC) in terms of recurrence-free survival (RFS) and cancer-specific survival (CSS). We found that membranous CD155 (mCD155)-positive cases had shorter periods of both RFS and CSS, whereas there was no association between cytoplasmic CD155 (cCD155) and survival outcomes. The results showed that CD155, especially mCD155, may serve as a poor prognostic marker in BC. ABSTRACT: Objective: To investigate the relationship between clinicopathological findings and membranous CD155 (mCD155) or cytoplasmic CD155 (cCD155) expression in bladder cancer (BC). Methods: We retrospectively analyzed 103 patients with BC who underwent radical cystectomy between 1990 to 2015 at Kitasato University Hospital. Immunohistochemical staining was performed to evaluate CD155 expression in tumor cells. Cases with > 10% expression on the membrane or cytoplasm of tumor cells were positive. The Fisher′s exact test was used for categorical variables and the Kaplan–Meier method was used for survival outcomes. Univariate and multivariate Cox regression hazard models were used to evaluate the survival risk factors. Results: Cases that were mCD155-positive were associated with high-grade tumors (p = 0.02), nodal status (p < 0.01), and pT stage (p = 0.04). No association with any clinicopathological factor was observed in the cCD155 cases. Kaplan–Meier analysis showed that mCD155-positive cases had shorter periods of recurrence-free survival (p = 0.015) and cancer-specific survival (p = 0.005). Only nodal status was an independent predictor for both cancer-specific survival and recurrence-free survival in multivariate analysis (p = 0.02 and p < 0.01, respectively). Conclusion: mCD155 expression may be a marker of an aggressive phenotype and a poor prognosis in patients with BC.