Chemoradiation Therapy for Unresected Extrahepatic Cholangiocarcinoma: A Propensity Score-Matched Analysis

Background: Unresected extrahepatic cholangiocarcinoma (uEHCC) remains a deadly disease. Guidelines for uEHCC recommend either chemotherapy alone (CT) or chemoradiotherapy (CRT). This study used the National Cancer Database (NCDB) to compare outcomes for patients treated with CT and those who underwent CRT.

Methods: Patients with initially diagnosed non-metastatic uEHCC from 2004 to 2014 were identified. Using Chi square analysis, patients who underwent CT were compared with those who received CRT. Uni- and multivariate Cox regression analyses were used to compare characteristics related to survival. Propensity score matching and shared frailty analysis were undertaken to correct for baseline differences between the two groups. Additional analyses were performed to compare survival for the minority of patients who underwent surgery and advanced-stage patients.

Results: The study identified 2996 patients with uEHCC. Chemoradiation was associated with better survival (median survival [MS], 14.5 months; hazard ratio [HR] 0.84; p < 0.001) than CT alone (MS, 12.6 months). Induction of CT before CRT was associated with a trend toward decreased risk of death compared with concurrent CRT (HR 0.81; p = 0.051). For the patients able to undergo surgery after initial treatment, MS was 24.5 months (HR 0.38; p < 0.001) versus 12.2 months for those who had no surgery. For these patients, CRT also was associated with better survival (MS, 31.2 months; HR 0.66; p = 0.001) than CT (MS, 22.1 months). Positive margins at surgery yielded survival equivalent to that with no surgery.

Conclusion: Although CRT may be associated with slightly better survival in uEHCC than CT alone, the majority of the benefit was observed for patients able to undergo eventual surgery.