A case of successful conversion surgery for unresectable gallbladder cancer treated with durvalumab in combination with gemcitabine plus cisplatin.

We report a rare case of a patient with initially unresectable gallbladder cancer who underwent conversion surgery with durvalumab in combination with gemcitabine plus cisplatin and achieved an R0 resection. A 68 year-old woman was found to have gallbladder cancer and multiple enlarged lymph nodes around the suprapancreatic rim and hepatic hilum invading the proper hepatic artery on computed tomography. The diagnosis was cT3cN2cM0, cStage IVB. After eight cycles of durvalumab in combination with gemcitabine plus cisplatin, all tumor markers became negative, and lymph node invasion of the hepatic artery disappeared. The patient underwent conversion surgery with gallbladder bed resection and regional lymph node dissection. There was no need for hepatic artery reconstruction. Pathology revealed ypT2aypN0ycM0, ypStage IIA, and radical resection was considered. Immunostaining of tissue collected at the time of endoscopic ultrasound-guided tissue acquisition revealed less than 1% programmed death ligand-1 expression. The patient continued adjuvant chemotherapy with single-agent durvalumab every 4 weeks and maintained a relapse-free survival of 8 months postoperatively. The utility of durvalumab in combination with gemcitabine plus cisplatin in unresectable gallbladder cancer independent of programmed death ligand-1 expression has been confirmed and may be an important option in future multimodal treatment, including conversion surgery.