Safety and Tumoricidal Effect of Low Dose Temoporfin Photodynamic Therapy in Patients With Inoperable Bile Duct Cancers (Foscan® Study)

Cholangiocarcinoma is a tumor associated with a grave prognosis. The only curative treatment is surgery or liver transplantation. Only about 10-20% of patients with the tumor are operated upon. In the majority of patients, the tumor is often diagnosed at a late stage. Many patients are not operated upon owing to their advanced age or comorbid illnesses. These patients suffer from intense pruritus a result of obstructive jaundice, recurrent biliary sepsis and progressive hepatic failure leading to death. Quality in life in these patients is poor. The median survival in these patients is around 6 months. The palliative treatment is stents inserted either at ERCP or through a percutaneous transhepatic route. Many return with recurrent cholangitis necessitating frequent stent changes. Photodynamic therapy (PDT) in combination with stenting is the only proven treatment that confers a survival benefit when compared to stenting alone. Two randomized controlled trials have shown significant survival advantage in patients treated by PDT in addition to stenting compared to stenting alone. Ortner et al. 1 randomized 39 patients with inoperable cholangiocarinoma to endoscopic stents with or without PDT. Median survival in those given PDT was 493 days compared to that of 98 days in those with stents alone. Survival difference was again wide in favor of PDT use in another randomized controlled study by Zoepf et al 2 (median survival 630 vs. 210 days). In addition, PDT improves quality of life and cholestasis in patients with cholangiocarcinoma. In a series from Germany, survival after PDT and stenting compared favorably to R1 and R2 resections. 3 Despite of the evidence, PDT for inoperable cholangiocarcinoma is not available in Hong Kong.

Meso-tetrahydroxyphenylchlorin (mTHPC, Foscan®) is a photosensitizer for PDT in cholangiocarcinoma. In compared with other agents such as Photofin and Photosan, PDT treatment using temoporfin at a low dose (3 mg per treatment) is associated with a deeper tissue penetration (4-6mm) and a reduced period of photosensitivity.

In this study, we hope to evaluate the safety of PDT using temoporfin plus endoscopic stents in patients with inoperable bile duct cancers. In addition as a preliminary study we sought to determine if the treatment can reduce tumor volume in the short term.