Intrahepatic cholangiocarcinoma (ICC) is an aggressive cancer arising from the bile ducts with a need for earlier diagnosis and a greater range of treatment options. KRAS/NRAS mutations are common in ICC tumours and 6–32% of patients also have isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) gene mutations associated with metabolic changes. This feasibility study investigated sequencing circulating tumour DNA (ctDNA) combined with metabolite profiling of plasma as a method for biomarker discovery in ICC patients. Plasma was collected from four ICC patients receiving radio-embolisation and healthy controls at multiple time points. ctDNA was sequenced using Ampliseq cancer hotspot panel-v2 on Ion Torrent PGM for single nucleotide variants (SNV) detection and with Illumina whole genome sequencing for copy number variants (CNV) and further targeted examination for SNVs. Untargeted analysis of metabolites from patient and control plasma was performed using liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-MS/MS). Metabolite identification was performed using multi-parameter comparisons with analysis of authentic standards, and univariate statistical analysis was performed to identify differences in metabolite abundance between patient and control samples. Recurrent somatic SNVs and CNVs were identified in ctDNA from three out of four patients that included both NRAS and IDH1 mutations linked to ICC. Plasma metabolite analysis revealed biomarker metabolites associated with ICC and in particular 2-hydroxyglutarate (2-HG) levels were elevated in both samples from the only patient showing a variant allele in IDH1. A reduction in the number of CNVs was observed with treatment. This study demonstrates that ctDNA and metabolite levels can be identified and correlated in ICC patient blood samples and differentiated from healthy controls. We conclude that combining genomic and metabolic analysis of plasma offers an effective approach to biomarker identification with potential for disease stratification and early detection studies.
The FOXFIRE (5-Fluorouracil, OXaliplatin and Folinic acid ± Interventional Radio-Embolisation) clinical trial combined systemic chemotherapy (OxMdG: Oxaliplatin, 5-fluorouracil and folic acid) with Selective Internal Radiation Therapy (SIRT or radio-embolisation) using yttrium-90 resin microspheres in the first-line management for liver-dominant metastatic colorectal cancer (CRC). We report clinical outcomes for patients having hepatic resection after this novel combination therapy and an exploratory analysis of histopathology. Multi-Disciplinary Teams deemed all patients inoperable before trial registration and reassessed them during protocol therapy. Proportions were compared using Chi-squared tests and survival using Cox models. FOXFIRE randomised 182 participants to chemotherapy alone and 182 to chemotherapy with SIRT. There was no statistically significant difference in the resection rate between groups: Chemotherapy alone was 18%, (n = 33); SIRT combination was 21% (n = 38) (p = 0.508). There was no statistically significant difference between groups in the rate of liver surgery, nor in survival from time of resection (hazard ratio (HR) = 1.55; 95% confidence interval (CI) = 0.83–2.89). In the subgroup studied for histopathology, microsphere density was highest at the tumour periphery. Patients treated with SIRT plus chemotherapy displayed lower values of viable tumour in comparison to those treated with chemotherapy alone (p < 0.05). This study promotes the feasibility of hepatic resection following SIRT. Resin microspheres appear to preferentially distribute at the tumour periphery and may enhance tumour regression.