Tumor Burden Dictates Prognosis Among Patients Undergoing Resection of Intrahepatic Cholangiocarcinoma: A Tool to Guide Post-Resection Adjuvant Chemotherapy?

Introduction While tumor burden (TB) has been associated with outcomes among patients with hepatocellular carcinoma, the role of overall TB in intrahepatic cholangiocarcinoma (ICC) remains poorly defined. Methods Patients undergoing curative-intent resection of ICC between 2000 and 2017 were identified from a multi-institutional database. The impact of TB on overall (OS) and disease-free survival (DFS) was evaluated in the multi-institutional database and validated externally. Results Among 1101 patients who underwent curative-intent resection of ICC, 624 (56.7%) had low TB, 346 (31.4%) medium TB, and 131 (11.9%) high TB. OS incrementally worsened with higher TB (5-year OS; low TB: 48.3% vs medium TB: 29.8% vs high TB: 17.3%, p < 0.001). Similarly, patients with low TB had better DFS compared with medium and high TB patients (5-year DFS: 38.3% vs 18.7% vs 6.9%, p < 0.001). On multivariable analysis, TB was independently associated with OS (medium TB: HR = 1.40, 95% CI 1.14-1.71; high TB: HR = 1.89, 95% CI 1.46-2.45) and DFS (medium TB, HR = 1.61, 95% CI 1.33-1.96; high TB: HR = 2.03, 95% CI 1.56-2.64). Survival analysis revealed an excellent prognostic discrimination using the TB among the external validation cohort (3-year OS; low TB: 44.8%, medium TB: 29.3%; high TB: 23.3%, p = 0.03; 3-year DFS: low TB: 32.7%, medium TB: 10.7%; high TB: 0%, p < 0.001). While neoadjuvant chemotherapy was not associated with survival across the TB groups, receipt of adjuvant chemotherapy was associated with increased survival among patients with high TB (5-year OS: 24.4% vs 13.4%, p = 0.02). Conclusion Overall TB dictated prognosis among patients with resectable ICC. TB may be used as a tool to help guide post-resection treatment strategies.