Abstract:Objective To investigate the effect and significance of miR-7 in the diagnosis and recurrence of bladder cancer patients. Methods Ninety patients with bladder cancer and 90 non-tumor subjects (30 in normal group, 30 in urinary stone group, 30 in urinary infection group)were enrolled in our hospital from 2014.12 to 2015.12. Serum and morning urine were detected by Real-Time PCR. The levels of miR-7 were analyzed for diagnostic value and relationship between prognosis and recurrence. Results Compared with the normal group, the expression of serum miR-7 mRNA in bladder cancer patients was decreased (P < 0.05). There was no difference in the expression of miR-7 mRNA in urine sediments among normal group, urinary stone group and urinary infection group (P > 0.05). Compared with the normal group, the expression of miR-7 mRNA in urine sediments of bladder cancer patients was decreased (P < 0.05). The diagnostic value of urine sediment miR-7 was greater than that of serum miR-7 (P < 0.05). With the aggravation of TNM staging in bladder cancer patients, the expression of miR-7 mRNA in serum and urine sediment of bladder cancer patients decreased (P < 0.05). Postoperative follow-up was performed on 90 patients with bladder cancer. The follow-up time was (1.36±0.59) years, and 25 of them had postoperative recurrence. The expression of miR-7 mRNA in serum and urine sediment of patients with recurrent bladder cancer was decreased (P < 0.05). Conclusions Serum and urinary sediment miR-7 can be used as a biological tumor marker for the diagnosis, prognosis and follow-up of bladder cancer.