Landscape of circulating tumor DNA profiling of advanced pancreatic cancer (PDAC).

289Background: PDAC has limited treatment options. Genomic analyses have led to development of targeted therapies now in several clinical trials, and may enable the discovery of new treatment options. However, biopsy often yields limited tissue, thus hampering tissue-based profiling opportunities. Data regarding circulating tumor DNA (ctDNA) profiling in PDAC during real time clinical practice is limited. Methods: We performed ctDNA NGS analysis in pts with advanced PDAC (December 2014–August 2018). ctDNA analysis was performed using Guardant 360 (Guardant Health, CA), which detects single nucleotide variants, amplifications, fusions, and specific insertion/deletion mutations in up to 73 different genes. The mutant allele fraction (MAF) for detected alterations was calculated relative to wild type in ctDNA. Therapeutic relevance (TR) was defined as possible treatments within OncoKB levels 1-3B and R1. The study was conducted in accordance with Mayo Clinic Institutional Review Board requirements. Results: ...