Objective:to investigate the effect of maximum transurethral cystectomy ((TURBT)) before radical cystectomy on the prognosis of patients with multiple bladder tumors.Methods:the clinical data and follow-up records of 90 patients with multiple bladder tumors treated in our hospital from August 2010 to August 2018 were analyzed retrospectively. There were 72 males and 18 females. The age ranged from 20 to 84 years old, with an average of (64.6 ±11.7) years. There were 50 cases of age <60 years old and 40 cases of ≥60 years old. The median age of male was 68 years old and that of female was 69 years old. The diameter of Tumor was ≥3 cm in 52 cases and <3 cm in 38 cases. There were 53 cases with 2 lesions and 37 cases with more than 2 lesions. According to the extent of TURBT resection, 55 patients (61.1%) were divided into maximum TURBT group, 42 males and 13 females, with an average age of (56.2±12.0) years. Tumor diameter ≥3 cm(n=29) and <3 cm(n=26). There were 35 cases (38.9%) in the non-maximal TURBT group, including 30 males and 5 females, with an average age of (59.8±13.4) years. In the non-maximum TURBT group. The diameter of tumor was ≥3 cm in 23 cases and <3 cm in 12 cases. There was no significant difference in preoperative data between the two groups ( P > 0.05). In the maximum TURBT group, all the tumors visible to the naked eye were completely removed, and the tissues were taken from the base and surrounding mucosa for pathological examination. Diagnostic TURBT group: multiple tumors in the bladder were found during the operation, the surface was rough, and there were no ureteral orifices on both sides. Samples of ureteral orifice and surrounding mucosal tissues were taken for biopsy, and the bladder tumor was not completely removed. Radical cystectomy was performed in both groups. The relationship between two different surgical methods and clinicopathological factors was analyzed. After that, the recurrence-free survival time (RFS) and overall survival time (OS) of patients were analyzed by Kaplan-Meier method, and the statistical difference of survival curve was analyzed by Log-rank method. Univariate Log-rank and multivariate Cox regression analysis were used to analyze the influencing factors of RFS and OS. Results:In this study, 90 cases of radical cystectomy were completed successfully. The postoperative follow-up time was 7-60 months, 1 case lost follow-up, and the median follow-up time was 30 (15-46) months. There was no significant difference in all data between maximum TURBT group and diagostic TURBT group ( P>0.05). Urethral recurrence occurred in 6 (6.7%) cases and pelvic recurrence in 9 (10%) cases after RC. 15 (16.7%) cases died, of which 8 cases died of postoperative pelvic recurrence, 3 cases died of myocardial infarction, 2 cases died of bone metastasis and 2 cases died of pulmonary metastasis. The results of Kaplan-Meier method showed that the 1-, 3-and 5-year overall survival rates of patients with RC after maximum TURBT were 96.67%, 86.05% and 80.86%, respectively, and the 1-, 3-and 5-year relapse-free survival rates were 89.97%, 76.93% and 71.41%, respectively. Univariate Log-rank results showed that pathological stage ( P=0.018), urethral recurrence ( P<0.01), pelvic recurrence ( P<0.01) and maximum TURBT ( P<0.01) were the risk factors of OS and RFS. The risk of death in patients with pelvic recurrence was higher than that in patients without pelvic recurrence ( HR=41.850, 95% CI 12.597-139.036, P<0.01). The risk of death in patients with urethral recurrence was higher than that in patients without urethral recurrence ( HR=8.128, 95% CI 1.551-42.606, P<0.01). The risk of death in patients with RC after maximum TURBT was lower than that in patients with diagnostic TURBT ( HR=0.164, 95% CI 0.036-0.746, P<0.01). Among them, there were only 2(3.9%) pelvic recurrence in patients with maximum TURBT combined with RC, 7(6.1%) pelvic recurrence and 6(6.7%) urethral recurrence in patients without maximum TURBT combined with RC, and there was significant difference between patients without maximum TURBT and patients without maximum urethral recurrence. Multivariate Cox analysis showed that urethral recurrence ( HR=8.128, 95% CI 1.551-42.606, P=0.013, P<0.01) and pelvic recurrence ( HR=41.850, 95% CI: 12.597-139.036, P<0.01) were independent risk factors for OS, and urethral recurrence ( HR=18.637, 95% CI 5.443-63.817, P<0.01) and pelvic recurrence ( HR=22.94, 95% CI 8.635-60.973, P<0.01) were independent risk factors for RFS. The maximum TURBT was the independent protective factor of OS ( HR=0.164, 95% CI 0.036-0.746 P<0.01) and RFS ( HR=0.153, 95% CI 0.048-0.493, P<0.01). Conclusions:For patients with multiple bladder tumors, radical cystectomy with maximum TURBT before radical cystectomy might reduce urethral and pelvic recurrence after radical cystectomy, and might improve the prognosis of patients with multiple bladder cancer. Maximum TURBT is an independent protective factor for OS and RFS. Urethral recurrence and pelvic recurrence are independent risk factors for OS and RFS.