{"entity":{"id":"paper-pietrasz-ctdna-prognostic-pancreatic-ccr-2017","kind":"paper","name":"Plasma circulating tumor DNA in pancreatic cancer patients is a prognostic marker","aka":[],"tldr":"Among 135 patients, those with detectable tumour DNA in blood lived 6.5 months against 19, and the more of it there was the shorter the survival; after surgery, finding it predicted early recurrence.","summary":"Blood samples were prospectively collected from consecutive pancreatic adenocarcinoma patients treated at one centre from 2011 to 2015, with circulating tumour DNA identified by targeted next-generation sequencing and picolitre droplet digital PCR. Of 135 patients (31 resectable, 36 locally advanced, 68 metastatic), 50 of 104 with advanced disease (48%) had detectable ctDNA at a median mutant allele fraction of 6.1%. Detection correlated strongly with poor overall survival (6.5 versus 19.0 months; multivariate hazard ratio 1.96), and allele-fraction tertiles gave 18.9, 7.8 and 4.9 months. Among 31 patients resected with curative intent, 6 had detectable ctDNA after surgery at a mean allele fraction of 4.4%, with shorter disease-free (4.6 versus 17.6 months) and overall survival (19.3 versus 32.2 months).","asOf":"2026-09-24","links":[{"label":"Pietrasz et al., Clin Cancer Res 2017: plasma ctDNA is prognostic in 135 patients","url":"https://doi.org/10.1158/1078-0432.CCR-16-0806"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/27993964/"}],"tags":[],"related":["ctdna-mrd-positive"],"cancers":["pancreatic","metastatic-pdac","resectable-pdac"],"sections":[],"technologies":["liquid-biopsy","mrd-testing"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["ctdna","cfdna","mrd"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":["clinical-cancer-research"],"dependsOn":[],"notes":[],"journal":"Clinical Cancer Research","year":2017,"doi":"10.1158/1078-0432.CCR-16-0806","pmid":"27993964","authors":"Pietrasz D, Pecuchet N, Garlan F, et al.","paperType":"observational","findings":["ctDNA detectable in 48% of advanced patients; overall survival 6.5 versus 19.0 months.","Allele-fraction tertiles: 18.9, 7.8 and 4.9 months.","Post-resection ctDNA: disease-free survival 4.6 versus 17.6 months."],"whatItMeans":"ctDNA quantity, not just presence, grades prognosis, which is why trials now stratify by allele fraction rather than by a yes or no.","caveats":["Single centre; assays differed between patients.","Only 31 resected patients."],"changedPractice":false,"participants":135},"route":"/key-papers/paper-pietrasz-ctdna-prognostic-pancreatic-ccr-2017/","neighbours":{"biomarker":[{"id":"ctdna-mrd-positive","kind":"biomarker","name":"ctDNA MRD positivity (molecular residual disease after curative treatment)","route":"/biomarkers/ctdna-mrd-positive/"}],"cancer":[{"id":"metastatic-pdac","kind":"cancer","name":"Metastatic pancreatic ductal adenocarcinoma","route":"/cancers/metastatic-pdac/"},{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"},{"id":"resectable-pdac","kind":"cancer","name":"Resectable pancreatic ductal adenocarcinoma","route":"/cancers/resectable-pdac/"}],"technology":[{"id":"liquid-biopsy","kind":"technology","name":"Liquid biopsy (ctDNA)","route":"/technologies/liquid-biopsy/"},{"id":"mrd-testing","kind":"technology","name":"MRD / molecular residual disease testing","route":"/technologies/mrd-testing/"}],"term":[{"id":"cfdna","kind":"term","name":"Cell-free DNA (cfDNA)","route":"/terms/cfdna/"},{"id":"ctdna","kind":"term","name":"Circulating tumour DNA (ctDNA)","route":"/terms/ctdna/"},{"id":"mrd","kind":"term","name":"Minimal / molecular residual disease (MRD)","route":"/terms/mrd/"}],"journal":[{"id":"clinical-cancer-research","kind":"journal","name":"Clinical Cancer Research","route":"/journals/clinical-cancer-research/"}]}}