{"entity":{"id":"paper-mody-biliary-ctdna-profiling-jco-po-2019","kind":"paper","name":"Circulating tumor DNA profiling of advanced biliary tract cancers","aka":[],"tldr":"Blood tests for tumour DNA found a mutation in three quarters of 124 patients with advanced bile duct or gallbladder cancer and a drug-relevant change in about half, showing the approach is feasible when tissue is hard to get.","summary":"From January 2015 to February 2018, 124 patients with locally advanced or metastatic biliary tract cancer at the Mayo Clinic underwent circulating tumour DNA testing with a clinically available assay, most (n = 122) on a 73-gene panel; about 70% had intrahepatic disease. 138 samples were included.\n\nExcluding variants of unknown significance, 105 samples (76%) had one or more alterations, with an average of three alterations per sample and a median allelic fraction of 0.52%. Therapeutically relevant alterations were observed in 76 patients (55%), including BRAF mutations, ERBB2 amplifications, FGFR2 fusions, FGFR2 mutations and IDH1 mutations seen in 21% of patients. A different spectrum was observed in patients under 50.","asOf":"2026-09-24","links":[{"label":"Mody et al., JCO Precis Oncol 2019: circulating tumour DNA profiling of 124 biliary tract cancers","url":"https://doi.org/10.1200/po.18.00324"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/35100741/"}],"tags":[],"related":[],"cancers":["gallbladder","cholangiocarcinoma","biliary-tract-cancer"],"sections":[],"technologies":["liquid-biopsy"],"targets":["her2","braf","fgfr2","idh"],"drugs":["guardant360-cdx"],"companies":["guardant-health"],"institutions":["mayo-clinic"],"pathways":[],"terms":["ctdna"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":["jco-precision-oncology"],"dependsOn":[],"notes":[],"journal":"JCO Precision Oncology","year":2019,"doi":"10.1200/po.18.00324","pmid":"35100741","authors":"Mody K, Kasi PM, Yang J, et al.","paperType":"observational","findings":["76% of 138 plasma samples carried at least one alteration; median allelic fraction 0.52%.","Therapeutically relevant alterations in 55% of patients, including ERBB2 amplification, BRAF, FGFR2 and IDH1.","Different alteration spectrum in patients under 50."],"whatItMeans":"Biliary tumours are often diagnosed on tiny biopsies or brushings, so a blood-based panel that detects HER2 amplification and other targets in half of patients is a practical route to testing, with tissue confirmation where the blood is uninformative.","caveats":["Single centre, predominantly intrahepatic; gallbladder cancers were a minority.","Plasma panel (Guardant360) of 73 genes; low allelic fractions mean negatives do not exclude a tissue alteration."],"changedPractice":false,"participants":124},"route":"/key-papers/paper-mody-biliary-ctdna-profiling-jco-po-2019/","neighbours":{"cancer":[{"id":"biliary-tract-cancer","kind":"cancer","name":"Biliary tract cancer (all types)","route":"/cancers/biliary-tract-cancer/"},{"id":"cholangiocarcinoma","kind":"cancer","name":"Biliary tract cancer (cholangiocarcinoma)","route":"/cancers/cholangiocarcinoma/"},{"id":"gallbladder","kind":"cancer","name":"Gallbladder cancer","route":"/cancers/gallbladder/"}],"technology":[{"id":"liquid-biopsy","kind":"technology","name":"Liquid biopsy (ctDNA)","route":"/technologies/liquid-biopsy/"}],"target":[{"id":"braf","kind":"target","name":"BRAF","route":"/targets/braf/"},{"id":"fgfr2","kind":"target","name":"FGFR2","route":"/targets/fgfr2/"},{"id":"her2","kind":"target","name":"HER2","route":"/targets/her2/"},{"id":"idh","kind":"target","name":"IDH1 / IDH2","route":"/targets/idh/"}],"drug":[{"id":"guardant360-cdx","kind":"drug","name":"Guardant360 CDx","route":"/drugs/guardant360-cdx/"}],"company":[{"id":"guardant-health","kind":"company","name":"Guardant Health","route":"/companies/guardant-health/"}],"institution":[{"id":"mayo-clinic","kind":"institution","name":"Mayo Clinic","route":"/institutions/mayo-clinic/"}],"term":[{"id":"ctdna","kind":"term","name":"Circulating tumour DNA (ctDNA)","route":"/terms/ctdna/"},{"id":"her2-testing-in-biliary-cancer","kind":"term","name":"HER2 testing in biliary tract cancer (IHC, ISH and NGS)","route":"/terms/her2-testing-in-biliary-cancer/"}],"journal":[{"id":"jco-precision-oncology","kind":"journal","name":"JCO Precision Oncology","route":"/journals/jco-precision-oncology/"}]}}