This study collected consecutively the data of 463 patients with gastric adenocarcinomas who underwent curative gastrectomy with lymphadenectomy at our institution between January 2017 and February 2022. The Institutional Review Board of St. Vincent's Hospital, The Catholic University of Korea approved this study (VC22RISI0177). Informed consent of the patients was waived because of the retrospective nature of the study. The inclusion criteria were: (1) gastric adenocarcinoma; (2) R0 resection; (3) formalin-fixed paraffin-embedded tissue (FFPE) blocks available for analysis. Patients who had undergone previous surgery, palliative resection, chemotherapy, or radiation therapy were excluded. All patients underwent gastrectomy with lymphadenectomy based on the Korean Practice Guideline for Gastric Cancer 2018 [18]. After the surgery, clinical follow-up data were collected every 6 months during the first year and then every year thereafter. Disease-free survival (DFS) was defined as the length of time from curative surgery to the first tumor recurrence or distant metastasis. Overall survival (OS) was defined as the time from curative surgery to death from any cause.
The data of 460 gastric cancer patients who underwent curative gastrectomy with D2 lymph node dissection between January 2017 and February 2022 were analyzed. The clinicopathological features and prognosis of the patients with EBV-positive gastric cancers were compared with those of EBV-negative gastric cancers. Immunohistochemistry for epidermal growth factor receptor (EGFR), C-erb B2, Ki-67, and p53 was performed. Additionally, in situ hybridization was conducted to detect EBV, and microsatellite instability (MSI) analysis was used to assess the deficiency in mismatch repair (MMR) genes.