Young-onset gastric cancer and Epstein–Barr Virus (EBV) – a major player in the pathogenesis?
Assaf Moore, Elad Hikri, Tal Goshen‐Lago, Tamar Barkan, Sara Morgenstern, Elena Brook, Annett Maderer, Wilfried Roth, Noa Gordon, Hanoch Kashtan, Baruch Brenner, Markus Moehler, Irit Ben Aharon
Abstract
OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer death, occurs predominantly in older age, with increasing incidence in young patients. The Cancer Genome Atlas indicates four subtypes for GC among which Epstein-Barr virus (EBV) subtype is estimated at 8.7%. We aim to determine the prevalence of EBV subtype in young GC patients (≤45 years) compared with an average-onset cohort (≥55 years) and characterize the clinicopathologic pattern of young-onset GC. METHODS: Gastric cancer samples of patients of both cohorts were screened for EBV by qPCR. Additional staining was done for Human epidermal growth factor receptor 2 (HER2), microsatellite instability (MSI) status and Programmed death-ligand 1 (PD-L1). Demographics and clinical data were retrieved from the medical records. RESULTS: Thirty-nine young-onset and 35 average-onset GC patients were reviewed. There was no apparent difference in tumor location, family history, histology and HER2 status between the cohorts. More young-onset patients were diagnosed with metastatic disease (27% vs 9%, p = 0.0498). EBV was significantly more prevalent in the young-onset cohort (33% vs 11%, p = 0.025). 15/17 EBV positive patients were under the median age of diagnosis for GC in the US (68 years). MSI-H was found only in the average-onset cohort [0% vs 27%, p = 0.001). PD-L1 positivity was higher in the young-onset cohort (31% vs 3%, p = 0.002). CONCLUSION: Our study indicates that EBV subtype is more prevalent in young-onset GC and may play a key role in the pathogenesis. Higher rate of PD-L1 positivity in young-onset GC could change treatment strategies. We are currently evaluating these findings in a prospective trial.