FoundationOne® CDx gene profiling in Japanese pancreatic ductal adenocarcinoma patients: a single-institution experience

Purpose: The aim of this study was to investigate the genetic mutation profiles of Japanese pancreatic ductal adenocarcinoma (PDAC) patients. Methods: Next-generation sequencing was performed using FoundationOne® CDx on 17 PDAC patients who were treated by surgical resection at Kyushu University Hospital between February 2016 and January 2019. The tumor mutational burden and microsatellite instability status were also assessed. Results: There were 16 patients (94%) with KRAS mutations, 13 (76%) with TP53 mutations, three (18%) with SMAD4 mutations, and one (6%) with a CDKN2A mutation. All patients had at least one pathogenic variant or a likely pathogenic variant. No patient had targeted therapies that matched with any clinical benefit according to FoundationOne® CDx. An unresectable PDAC patient with BRCA2-mutant disease was successfully treated by conversion surgery using platinum-based neoadjuvant chemotherapy. Conclusions: Currently, FoundationOne® CDx might be difficult to use on PDAC patients, although further investigations with larger study populations are called for.