A case from the future of HPB surgical oncology: resection of biliary tract cancer after immunotherapy.

Biliary tract cancers (BTCs) have limited response to systemic therapy and poor prognosis. Immunotherapy in BTCs has been investigated in recent years. Here, we report a case of locally advanced, unresectable gallbladder adenocarcinoma that progressed on chemotherapy. The patient was then treated with ipilimumab and nivolumab, which resulted in tumor shrinkage and autoimmune hepatitis, but established technical resectability. He underwent complete resection through extended right hepatectomy with en bloc cholecystectomy bile duct resection, hepatic and portal lymphadenectomy and Roux-Y hepaticojejunostomy reconstruction. The final pathology revealed a pathologic complete response. The scope of operative intervention after immunotherapy is still evolving for BTCs. Establishing resectability in tumors not susceptible to cytotoxic agents but responding to immunotherapy not only facilitates curative intent resection but also enhances the importance of infection prevention through operative stent-free long-term biliary decompression. Immunotherapy may also carry a unique risk profile for post-operative morbidity potential as in this case with autoimmune hepatitis.