RFA for Malignant Biliary Obstruction

Pancreatic cancer and cholangiocarcinoma are the most common causes of malignant biliary obstruction. They are diseases of increasing incidence and unfavorable prognosis. Only a minority of patients have a localized disease and are indicated for surgery with a chance of long-term survival. Locally advanced and metastatic tumors are treated with palliative chemotherapy or chemoradiotherapy; the results of such treatments are unsatisfactory. The average survival of patients with unresectable disease is 6 months and only 5 - 10 % of patients survive 5 years. Chemotherapy and radiotherapy can be used, however only with a palliative effect. Biliary drainage is an integral part of palliative treatment. Endoscopically or percutaneously placed stents improve quality of life, decrease cholestasis and pruritus, but do not significantly improve survival. Biliary stents get occluded over time, possibly resulting in acute cholangitis and require repeated replacement. Endoluminal biliary photodynamic therapy (PDT) and radiofrequency ablation (RFA), locally active endoscopic methods, have been increasingly used in recent years in palliative treatment of patients with malignant biliary obstruction. In photodynamic therapy, improved survival has been shown in two randomized controlled trials; however the technique suffers from technical complexity, high cost and low availability. In RFA, application of low voltage high frequency current during radiofrequency ablation results in tissue destruction by heat. Its antitumor effect may also be related to systemic changes in antitumor immunity. The use of endoluminal biliary RFA has so far been reported only in small retrospective cohorts of patients. The aim of this randomized study is to compare efficacy of RFA plus stenting to stenting alone in palliative treatment of malignant biliary obstruction with survival as primary outcome. Secondary outcomes are stent patency, immediate and late complications, quality of life and effects on anti-tumor immunity in the RFA group.