Molecular mechanisms and novel therapeutic strategies of BCG-unresponsive non-muscle invasive bladder cancer: Emerging immunotherapy has become a new choice?

Objective:THigh-risk non-invasive bladder cancer(NMIBC)has a high rate of recurrence and disease progression.At present,there are still insufficient effective prevention and treatment methods,especially for patients who have failed BCG treatment.This article reviews the research progress of the molecular mechanism of BCG unresponsive NMIBC,and summarizes the current status and prospects of emerging therapeutic strategies represented by immunotherapy,providing a theoretical basis for the immunotherapy of BCG non-reactive NMIBC.Methods:We searched the PubMed and CNKI journal full-text database search system for keywords"non-muscle invasive bladder cancer,BCG unresponsive,disease recurrence,disease progression,and immunotherapy"with 126 English and 538 Chinese articles.The literature,as well as the relevant clinical research in ClinicalTrials.gov,were integrated together to obtain the results.Results:Immunotherapy was performed in various types of tumors,and the use of immunotherapeutic drugs with different oncotargets administered alone,sequentially or in combination for the treatment of BCG-unresponsive NMIBC have achieved favorable effects,and more Clinical research is still ongoing.Conclusion:Immunotherapy is currently the most promising treatment for cancer,and it is indispensable for patients with NMIBC,both biologically and clinically.We look forward to more laboratory and clinical research in immunotherapy in the future.