Intrahepatic cholangiocarcinoma: can imaging phenotypes predict survival and tumor genetics?

PURPOSE: On computed tomography (CT), intrahepatic cholangiocarcinomas (ICC) are a visibly heterogeneous group of tumors. The purpose of this study was to investigate the associations between CT imaging phenotypes, patient survival, and known genetic markers.

METHODS: A retrospective study was performed with 66 patients with surgically resected ICC. Pre-surgical CT images of ICC were assessed by radiologists blinded to tumor genetics and patient clinical data. Associations between qualitative imaging features and overall survival (OS) and disease-free survival (DFS) were performed with Cox proportional hazards regression and visualized with Kaplan-Meier plots. Associations between radiographic features and genetic pathways (IDH1, Chromatin and RAS-MAPK) were assessed with Fisher's Exact test and the Wilcoxon Rank sum test where appropriate and corrected for multiple comparisons within each pathway using the False Discovery Rate correction.

RESULTS: Three imaging features were significantly associated with a higher risk of death: necrosis (hazard ratio (HR) 2.95 95% CI 1.44-6.04, p = 0.029), satellite nodules (HR 3.29, 95% CI:1.35-8.02, p = 0.029), and vascular encasement (HR 2.63, 95% CI 1.28-5.41, p = 0.029). Additionally, with each increase in axial size, the risk of death increased (HR 1.14, 95% CI 1.03-1.26, p = 0.029). Similar to findings for OS, satellite nodules (HR 3.81, 95% CI 1.88-7.71, p = 0.002) and vascular encasement (HR 2.25, 95% CI 1.24-4.06, p = 0.019) were associated with increased risk of recurrence/death. No significant associations were found between radiographic features and genes in the IDH1, Chromatin or RAS-MAPK pathways (p = 0.63-84).

CONCLUSION: This preliminary analysis of resected ICC suggests associations between CT imaging features and OS and DFS. No association was identified between imaging features and currently known genetic pathways.