Proton beam therapy improves OS in patients with ICC

CHICAGO — In a phase 2 trial, hypofractionated proton beam therapy was effective in improving overall survival in patients with intrahepatic cholangiocarcinoma, according to a poster presented at the ASCO Annual Meeting.

“In this study, we prospectively evaluated whether high dose, hypofractionated radiation therapy delivered with ablative intent using proton beam therapy could produce long-term local control in patients with unresectable intrahepatic cholangiocarcinoma,” Theodore S. Hong, MD, associate professor, department of radiation oncology, Harvard Medical School, and director, gastrointestinal service, radiation oncology at Massachusetts General Hospital, told Healio.com/Hepatology. “We were able to successfully demonstrate a 2-year actuarial local control exceeding our intended goal of 80%.”

Theodore S. Hong

Between 2009 and 2014, Hong and colleagues enrolled 93 patients in the study, of which 90 could be evaluated, to receive proton beam therapy (PBT). The therapy was given in 15 fractions to a maximum total dose of 67.5 GyE, according to the abstract. Of the patients, 41 had intrahepatic cholangiocarcinoma (ICC), two had mixed ICC and hepatocellular carcinoma and 47 had HCC. The median follow-up was 13 months.

The median tumor size was 6 cm and the median dose of radiation therapy the patients received was 58 GyE.

The researchers conducted an ICC-specific analysis and out of 43 patients with ICC, 22 survived with a 2-year local control of 96%, median OS of 21 months (95% CI, 13-29) and median progression-free survival (PFS) of 9 months (95% CI, 6-24), according to the research.

After excluding patients with cirrhosis (n = 38), the median OS was 23 months (95% CI, 15-49), median PFS was 10 months (95% CI, 5-24), 2-year OS rate was 48% and 2-year PFS rate was 38%.

Over the course of the trial, 14% of patients developed grade 3 radiation therapy-related toxicity, including thrombocytopenia (n = 2); hyperbilirubinemia (n = 2); gastric ulcer (n = 1); pain (n = 1); elevated liver function test (n = 1); and liver failure or ascites (n = 1).

“High dose PBT for ICC results in high rates of [local control] and OS,” the researchers concluded.

Hong stated: “These results form the basis of NRG GI001, a randomized trial of unresectable intrahepatic cholangiocarcinoma in which patients receiving chemotherapy with gemcitabine and cisplatin will be randomized to radiation or chemotherapy alone.” – by Melinda Stevens

Reference:

Hong TS, et al. Abstract 4020. Presented at: ASCO Annual Meeting; May 29-June 2, 2015; Chicago.

Disclosures: Hong reports his institution receives research funding from Novartis.