Sub-staging specific differences in recurrence-free, progression-free and cancer-specific survival for patients with T1 bladder cancer: a systematic review and meta-analysis

Abstract

Background: The efficiency of the T1 sub-staging system on categorizing bladder cancer (BC) patients into subgroups with different clinical outcomes was unclear. We summarized relevant evidences, including recurrence-free survival (RFS), progression-free survival (PFS) and cancer-specific survival (CSS), to analyze the prognostic significance of T1 sub-stage.Methods: Systematic literature searches of MEDLINE, EMBASE and the Cochrane Library were performed. We pooled data on recurrence, progression, and CSS from 35 studies.Results: The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) indicated the difference in RFS between T1a sub-stage and T1b sub-stage (HR1.28, 95%CI 1.14-1.43). The significant difference was observed in PFS between the two arms (HR 2.18, 95%CI 1.95-2.44). Worse CSS was found in T1b patients than T1a patients (HR 1.45, 95%CI 1.28-1.64).Conclusions: T1 sub-staging system based on the invasion depth into muscularis mucosae (MM) can be a significant prognostic factor for RFS, PFS, and CSS of patients with T1-BC. Urologists and pathologists are encouraged to work together to give a precise sub-stage classification of T1-BC, and T1 sub-staging system should be a routine part of any histopathological report when possible.Different treatment strategies need to be developed for both T1a-BC and T1b-BC.