Patients

The study group comprised of four patients who underwent gastrectomy for gastric cancer at the Department of Surgery, Juntendo University Shizuoka Hospital, Japan between May 2012 and June 2012. We selected four patients who had diverse characteristics because we focused on an associated analysis of mutated genes and clinical characteristics using a commercial sequencing panel. Fresh cancer and normal stomach samples were collected immediately after surgical removal. Normal fresh tissues were collected from surgical margins that were distant from the cancer sites. Thereafter, the samples were fixed in 10% neutral formalin for 24–72 h. FFPE cancer tissues and normal tissues were examined histologically. Mutation analysis of both fresh and FFPE tissues was performed employing the cancer panel using a next-generation sequencer (Illumina MiSeq^®). The medical records of the patients were reviewed retrospectively. Written informed consent was obtained from all the patients. This experiment was approved by the Ethics Committee of Juntendo University Shizuoka Hospital.