Identification and characterization of a novel adenomatous polyposis coli mutation in adult pancreatoblastoma

During next generation sequencing (NGS) analysis, many missense mutations were found in a well-known oncogene, many of which were variant of uncertain significance mutations. We recently treated an adult patient with pancreatoblastoma by chemotherapy. Using an NGS cancer panel, we found a previously unreported missense mutation in the 1835 codon of the adenomatous polyposis coli (APC) gene. We also found a heterogeneous mutation in the 1835 codon of the APC gene in the patient's germline by Sanger sequencing. Although this patient did not have a history of familial adenomatous polyposis, functional analysis suggested the R1835G mutant APC showed attenuated repression of Wnt/β-catenin signaling activity. This is the first report showing a novel APC missense mutation involved in the onset of adult pancreatoblastoma.