Circulating tumor DNA: a help to guide therapeutic strategy in patients with borderline and locally advanced pancreatic adenocarcinoma?

Background: prognostic biomarkers could be useful to better select patients with borderline resectable (BR) or locally advanced (LA) pancreatic adenocarcinoma (PA) for chemoradiotherapy (CRT) and/or secondary resection. Aims: The main objective of this work was to study characteristics, received treatments and prognostic of patients with BR or LA PA according to their baseline circulating tumor DNA status and, for secondary objective, neutrophil-to-lymphocyte Ratio (NLR). Methods: ctDNA status at baseline was determined using Next Generation Sequencing in a consecutive monocentric cohort of patients with a BR or LA PA. Results: 69 patients were included, 31 with BR PA and 38 with LA PA. 14 (20.3%) patients had baseline positive ctDNA. Five (7.8%) patients had NLR> 5. Patients with positive ctDNA had 3.7 months shorter progression free survival (p = 0.006). Patients with positive ctDNA had earlier progression after the beginning of CRT (4.4 vs 7.1 months; p = 0.068) and shorter relapse free survival after secondary resection (9.2 vs 22.9 months; p = 0.016). Conclusions: positive ctDNA at baseline was associated with a worse prognosis in patients with BR or LA PA. These data are exploratory and must be confirmed in further prospective trials.