Membranous Expression of Heart Development Protein with EGF-like Domain 1 Is Associated with a Good Prognosis in Patients with Bladder Cancer

Objective: To investigate the correlation between total protein expression of heart development protein with EGF-like domain 1 (HEG1) and clinicopathological characteristics in patients with bladder cancer (BC) after radical cystectomy (RC). Patients and Methods: We retrospectively analyzed data from 110 patients who underwent RC at Kitasato University Hospital. And we prepared an anti-HEG1 monoclonal antibody W10B9, which can detect total HEG1 protein. HEG1 protein expression in tumor cells was evaluated separately for membrane and cytoplasmic staining using immunohistochemistry. Results: Membranous HEG1 expression was associated with absent lymphovascular invasion (p < 0.01) and low pT stage (p < 0.01). Kaplan–Meier analysis revealed that the membranous HEG1-positive group had significantly long recurrence-free survival (RFS) (p < 0.01) and cancer-specific survival (p = 0.01). Expression of membranous HEG1 was identified as an independent prognostic factor for RFS (p = 0.04). There were no significant differences between cytoplasmic HEG1 expression and clinicopathologic factors including prognosis. Conclusion: The expression of membranous HEG1 could serve as a favorable prognostic indicator in patients with BC treated with RC.