Association between treatment facility volume, therapy types and overall survival in patients with intrahepatic cholangiocarcinoma

Background: To determine the association between the number of patients with intra-hepatic cholangiocarcinoma (IHCC) treated annually at a treatment facility (volume) and overall survival (outcome). Methods: Patients with IHCC reported to the National Cancer Database (years 2004–2015) were included. We classified facilities by tertiles (T; mean IHCC patients treated/year): T1: <2.56; T2: 2.57–5.39 and T3: ≥5.40. Volume–outcome relationship was determined by using Cox regression adjusting for patient demographics, comorbidities, tumor characteristics, insurance type and therapy received. Results: There were 11,344 IHCC patients treated at 1106 facilities. On multivariable analysis, facility volume was independently associated with all-cause mortality (p < 0.001). The unadjusted median OS by facility volume was: T1: 5 months (m), T2: 8.1 m, and T3: 13.1 m (p < 0.001). Compared with patients treated at T3 facilities, patients treated at lower-tertile facilities had significantly higher risk of death [T2 hazard ratio (HR), 1.12 [95% CI, 1.05–1.23]; T1 HR, 1.21 [95% CI, 1.11–1.33]. Patients treated at high-volume centers were more likely to get surgery (34.6 vs 13.1%) and adjuvant therapy. Conclusion: IHCC patients treated at high-volume facilities had a significant improvement in OS and were more likely to receive surgery and adjuvant therapy as compared to that of patients at low-volume facilities.