Extrahepatic cholangiocarcinoma is a malignant tumor that is highly malignant and difficult to diagnose and treat early. Endobiliary radiofrequency ablation (RFA) has been reported to be a beneficial treatment option for palliation of malignant biliary strictures. Within the bile duct, RFA appears to be safe and may result in decreased tumor ingrowth. To date, little is known about the role of the addition of systemic chemotherapy to RFA for cholangiocarcinoma. The aim of this study is to compare the efficacy and safety of RAF combined with Gemcitabine and S-1 in patients with unresectable cholangiocarcinoma.

Over 60 % of common bile duct (CBD) obstructions are due to malignancy, and the majority of neoplasms are unresectable at the time of diagnosis. Biliary drainage with placement of metal or plastic stents for palliation is the therapy of choice in this set of patients.

Radiofrequency ablation (RFA) is well established method for treatment of some solid tumors, like liver cancer, lung cancer, etc. Recently, an endoscopically applicable radiofrequency probe, HabibTM EndoHBP catheter, was approved for clinical use. RFA uses a high-frequency alternating current to generate heat and achieve coagulative necrosis when in contact with tissue. Many studies showed RFA with biliary stent was a beneficial treatment option for palliation of malignant biliary strictures. However, most of therapeutic effects were expected to delay bile duct obstruction rather than to decrease the tumor. Recently orally available chemotherapeutic agent, S-1, an oral fluoropyrimidine, was reported as effective in patients with bile duct adenocarcinoma. To date, little is known about the role of the addition of systemic chemotherapy to RFA for cholangiocarcinoma.

The aim of this study is to compare the efficacy and safety of RAF combined with Gemcitabine and S-1 in patients with unresectable cholangiocarcinoma

Inclusion Criteria:

• Obtention of a written informed consent.
• Patient with histologically proved cholangiocarcinoma ; histologic diagnosis must be proved by biliary brushing, bile cytology, endobiliary biopsy under Spyglass, or by EUS-FNA.
• Patient with Karnofsky score > 60， ECOG>level 2
• Patient capable of fill in the quality of life questionnaire
• For the first time treatment
• CT, MRCP, EUS and other examinations indicate that the tumor has locally infiltrated large blood vessels and cannot be surgically removed

Exclusion Criteria

• No written informed consent
• Patients under or already treated by radiotherapy or chemotherapy treatment for cholangiocarcinoma.
• Pregnant, parturient or breastfeeding women
• Serious abnormalities in liver and kidney function and coagulation function
• The ERCP guide wire cannot pass the stricture due to severe biliary stricture
• Merge with other malignant tumors
• Use other treatments that may affect the observation, such as radioactive particles or seed stent implantation, P53 injection, oral chemotherapy, interventional therapy, etc.