This is multicentric, single-arm, observational, investigator-drive study investigating the efficacy of liver transplantation after successful downstaging/disease control of unresectable perihilar cholangiocarcinoma using chemotherapy +/- immunotherapy and stereotactic body radiation therapy (SBRT).

Patients with unresectable pCCA who fit within inclusion criteria will be enrolled in the study. They will undergo staging laparoscopy with nodal sampling at the hepatic hilum. In case of negative staging (no peritoneal carcinomatosis, no positive hilar lymph nodes, negative peritoneal washing), they will receive downstaging with gemcitabine-cisplatin +/- durvalumab for 2 cycles, followed by SBRT, followed by at least 4 other cycles of gemcitabine-cisplatin +/- durvalumab. After downstaging, they will undergo disease restaging and, if at least disease stability is confirmed, they will undergo transplant screening and listing. Treatment with gemcitabine-cisplatin + durvalumab will continue until liver transplant, progression or unacceptable toxicity.

During listing, restaging will be performed every two months with CT scan and/or MRI, molecular markers and FDG-PET. The target interval between listing and transplant should be less than 90 days.

Inclusion Criteria:

• Diagnosis of unresectable peripheral cholangiocarcinoma arising one centimeter or more above the superior pancreatic margin, with tumor diameter ≤ 3 cm, diagnosed by:
• Transcatheter biopsy or brush cytology
• CA-19.9 > 100 mg/ml and/or a mass on cross-sectional imaging with a malignant appearing stricture on cholangiography
• Biliary ploidy by FISH with a malignant appearing stricture on cholangiography
• Age between 18 years and 70 years
• Absence of intra- and extrahepatic metastases
• Absence of lymph-nodal metastases at any site
• Biliary stenting of all liver districts
• No contraindications to liver transplantation
• No concomitant malignancies or history of other malignancies in the previous 5 years
• Written informed consent

Exclusion Criteria:

• Intrahepatic cholangiocarcinoma
• Uncontrolled infection
• Concomitant malignancies or history of other malignancies in the previous 5 years

Patients with liver-limited unresectable perihilar cholangiocarcinoma with no other non-oncological contraindication to liver transplantation