ECOG-ACRIN E5103 (E5103) was a phase III adjuvant breast cancer trial that randomized 4994 patients with node-positive or high-risk node-negative breast cancer. Whole exome sequencing in the germline (blood) DNA was conducted in 672 patients to investigate the association of genetic variants with chemotherapy efficacy and toxicities.: Sample 254671
Library preparation was performed according to the manufacturer's guidelines. Exomes were enriched from genomic DNA (50-100 ng) via Ion AmpliSeq™ Exome RDY kits. Libraries were subjected to magnetic bead-based clean up and quantified by qPCR prior to sequencing. Adapters and barcodes were incorporated during library construction, which allowed for two samples to be pooled per Ion PI™ chip. Templates were prepared on Ion Chef™ Systems then sequenced on Ion Proton™ Sequencers (LifeTechnologies) for 520 flows.