Abstract: Bladder cancer is among the most prevalent malignancies affecting the urinary system. Patients diagnosed with non⁃muscle⁃invasive bladder cancer (NMIBC) necessitate prolonged and intensive surveillance due to the disease's  high recurrence rate. Although cystoscopy remains the "gold standard" for diagnosis and monitoring, its invasive nature poses risks of pain, infection and hematuria, which can lead to poor compliance. In recent years,  liquid biopsy technologies have rapidly advanced, with various detection methods based on protein, fluorescence in situ hybridization, RNA, DNA mutation, copy number variation, DNA methylation, circulating tumor DNA (ctDNA) have shown significant promising  in the early diagnosis, recurrence monitoring and prognosis assessment of bladder cancer. Despite these advancements, the clinical implementation of these biomarkers faces substantial challenges and has not yet been adopted as  a routine diagnostic approach. This review systematically summarizes the research progress on liquid biopsy biomarkers for bladder cancer and explores the potential of multi⁃omics integration strategies to enhance the clinical translational value.

Key words: Bladder cancer, Liquid biopsy, Biomarker, Circulating tumor DNA, DNA methylation, Multi?omics integration