Background: Circular RNAs (circRNAs), a type of noncoding RNA, are associated with the occurrence and development of cancers. In recent years, their potential as biomarkers for bladder cancer (BC) has attracted increased attention. Aims: To reveal the value of circRNAs in the prognosis of BC. Methods: Relevant studies were collected to extract the clinicopathological data and overall survival (OS) of patients with BC. We then evaluated their tumor-related clinicopathological indicators using pooled odds ratio (OR) and 95% confidence interval (CI). Hazard ratio (HR) and 95% CI were used to estimate the OS of BC patients who expressed abnormal circRNAs. Results: The results indicate that seven circRNAs (circMYLK, circASXL1, hsa_circ_0000144, circ-VANGL1, circGprc5a, circZFR, and circ-cTFRC) whose expression was upregulated in tumor tissues, are associated with poor clinicopathological features (tumor/node/metastasis [TNM] stage: OR = 4.86, 95% CI: 2.53-9.34; histological grade: OR = 3.71, 95% CI: 2.37-5.79; lymph node metastasis: OR = 3.23; 95% CI: 2.15-4.88; recurrence: OR = 5.33; 95% CI: 2.27-12.52) and poor prognoses (OS: HR = 1.69; 95% CI: 1.17-2.44). We also found that seven circRNAs (circMTO1, circ-ITCH, circUBXN7, circFNDC3B, circ-ZKSCAN1, circPICALM, and circACVR2A) that were downregulated in tumors were associated with better clinicopathological indicators (TNM stage: OR = 0.23, 95% CI: 0.14-0.38; histological grade: OR = 0.21, 95% CI: 0.13-0.33; lymph node metastasis: OR = 0.26; 95% CI: 0.15-0.47) and better prognoses (OS: HR = 0.42; 95% CI: 0.30-0.58). Conclusion: Our results suggest that certain circRNAs are related to the clinicopathological characteristics and prognosis of BC patients, and may potentially be used as biomarkers.
Keywords: bladder cancer; circular RNA; meta-analysis; prognosis.