We identified a number of variants in healthy individuals and patients with pancreatic cancer using NOIR-SS. Then, we applied a bioinformatic filter, called the CV78 filter, to select ctDNA variants based on the COSMIC database. Variants with numbers of entries exceeding a preset threshold were selected and regarded as somatic mutations specific to the tumor tissue; the other variants were discarded. We achieved near-complete elimination of variants present in control samples, and complete elimination of variants not present in tumor samples. The combined application of NOIR-SS and the CV78 filter is likely to successfully identify somatic mutations specific to ctDNA. Based on the evidence presented here, we support conducting a larger study for confirmation.