Advanced gallbladder cancer with high tumor mutation burden: a case report and literature review.

Background: Gallbladder cancer (GBC) is a common malignant tumor of the biliary system. It is characterised by insidious onset, rapid progression and poor prognosis. Symptoms often indicate advanced or late-stage disease, with a 5-year survival rate of only 5-15%. Case Description: We present a case study of a patient with GBC who had a tumor mutation burden (TMB) of 32.5/MB (≥10 muts/MB). The patient received mFOLFIRINOX as first-line chemotherapy, which demonstrated significant efficacy. After stabilizing the disease, a sequential chemotherapy regimen was chosen. This regimen combined the immune checkpoint inhibitor (ICI) toripalimab (JS001), a humanised IgG4 monoclonal antibody targeting programmed cell death protein 1 (PD-1), with S-1 therapy, an oral fluoropyrimidine derivative. However, this treatment did not provide any significant clinical benefit for the patient. Therefore, we hypothesise that combining immunotherapy with chemotherapy may be more effective as a first line treatment for high-TMB advanced GBC. This hypothesis needs to be validated in large-scale clinical studies. Conclusions: In summary, mFOLFIRINOX is a safe and effective first-line chemotherapy regimen for advanced GBC. The timing of combining immunotherapy with chemotherapy requires careful consideration. Further clinical trials involving immunotherapy in advanced GBC are necessary to identify biomarkers that can guide clinical decisions.