Abstract: Objective   To investigate the predictive effect of Ribophorin1 (RPN1) on postoperative recurrence of non-muscular invasive bladder cancer (NMIBC).  Methods   GEPIA2 database was used to analyze the difference of RPN1 mRNA expression in bladder cancer and its relationship with prognosis.76 paraffin specimens of patients who underwent transurethral resection for tumor in our hospital from May 2018 to May 2021 were collected,the normal tissues of 32 cases by cystoscopy were normal group.Immunohistochemistry was used to detect the expression of RPN1 protein in 76 patients with NMIBC,and the relationship between its expression and clinicopathological parameters of NMIBC as well as postoperative recurrence was studied.  Results   It was determined through a comprehensive analysis of the database that the expression levels of RPN1 mRNA in bladder cancer tissue were significantly augmented when compared to those found in normal bladder tissue.Immunohistochemical techniques showed for the identification of RPN1 protein predominantly localized to the cytoplasm of cells,and the positive expression rate of RPN1 protein in NMIBC patients was 64.47% (49/76).The positive expression rate of RPN1 protein in 32 normal tissues was 9.37% (3/32).The expression level of RPN1 protein in cancer tissues was significantly higher than that in normal bladder tissues (P<0.05),and the expression of RPN1 was closely correlated with tumor size,histological grade,pathological stage and recurrence (P<0.05). Survival analysis was conducted and revealed that patients with high RPN1 expression exhibited a notably diminished rate of recurrence-free survival in comparison to those with low RPN1 expression(P<0.05).Cox regression analysis determined that high RPN1 expression is a significant independent risk factor for post-surgical recurrence in instances of NMIBC.  Conclusion  RPN1 is highly expressed in NMIBC,and its expression level is correlated with recurrence and prognosis,which is expected to be a predictor of postoperative recurrence of NMIBC.

Key words: non-muscle invasive bladder cancer, RPN1, clinicopathological parameters, recurrence, prognosis