Treatment Selection and Survival Outcomes With and Without Radiation for Unresectable, Localized Intrahepatic Cholangiocarcinoma.

PURPOSE: Most patients with intrahepatic cholangiocarcinoma present with locally advanced disease not amenable to surgical resection. For these inoperable patients, chemotherapy alone is generally considered the standard of care, with limited data regarding the role of radiotherapy. We used the National Cancer Database to investigate care patterns and the impact of radiation as a component of combined modality therapy on overall survival.

METHODS: We queried the National Cancer Database for patients with nonmetastatic intrahepatic cholangiocarcinoma diagnosed from 2001 to 2011. Those undergoing surgery were excluded. All included patients were coded as having received chemotherapy. Kaplan-Meier overall survival estimates and univariate and multivariate Cox proportional hazards regression analyses were performed. Propensity score-matched analysis was performed to account for indication bias and mitigate heterogeneity between treatment groups.

RESULTS: One thousand six hundred thirty-six patients were identified with a median follow-up of 11.3 months. Median age was 63 years; 23% received combined modality therapy with radiation. Two-year overall survival for the entire cohort was 21%, and for the chemotherapy-alone and combined modality therapy groups, it was 20% versus 26%, respectively. On univariate analysis, overall survival was improved with combined modality therapy. On multivariate analysis, combined modality therapy remained significantly associated with improved overall survival, as did younger age, female sex, higher median income, lower comorbidity score, and earlier stage. Propensity score matched analysis confirmed the overall survival benefit associated with combined modality therapy.

DISCUSSION: In this largest reported analysis of combined modality therapy for localized, inoperable intrahepatic cholangiocarcinoma, the addition of radiation to chemotherapy was associated with an improvement in overall survival. Three quarters of inoperable patients in the United States do not receive radiation. Survival remains relatively poor for all patients, and we enthusiastically support ongoing randomized trials seeking to incorporate radiotherapy as a possible means to improve outcomes.