Published online Oct 28, 2017. doi: 10.3748/wjg.v23.i40.7292
Peer-review started: June 8, 2017
First decision: July 10, 2017
Revised: July 27, 2017
Accepted: August 15, 2017
Article in press: August 15, 2017
Published online: October 28, 2017
Processing time: 143 Days and 14.3 Hours
To determine the prevalence of Epstein-Barr virus (EBV)-associated gastric carcinomas in the North Region of Portugal and to study its clinicopathological characteristics.
We have performed a retrospective study including a total of 179 consecutive patients with gastric cancer (GC) submitted to gastrectomy during 2011 at the Portuguese Oncology Institute of Porto. Clinical and pathological data was collected from individual clinical records and inserted on a database with unique codification. Tumour tissues were collected from the institutional tumour bank. EBV was detected by in situ hybridization for the detection of EBV-encoded small RNAs (EBERs) and EBV latent proteins (LMP1 and LMP2A) were detected by immunohistochemistry.
The analysis showed that EBV-associated gastric carcinomas (EBVaGC) represents 8.4% (15/179) of all GC cases, with a significant differential distribution among histological types (P < 0.001): 100% (3/3) of medullary carcinomas, 100% (1/1) of adenosquamous carcinoma, 8.7% (8/92) of tubular adenocarcinomas, 8.0% (2/25) of mixed carcinomas and 2% (1/51) in poorly cohesive carcinomas. The analysis revealed a higher predominance of EBVaGC in the upper third and middle (cardia, fundus and body) of the stomach (P = 0.041), a significant lower number of regional lymph nodes invasion (P = 0.025) and a tendency for better prognosis (P = 0.222). EBV latent protein expression revealed that all EBVaGC cases were LMP1-negative, nevertheless 6 cases (40%) expressed LPM2A, which reveals that these cases show a distinct EBV-Latency profile (latency II-like).
EBVaGC represents 8.4% of all GC in the North Region of Portugal. The EBV-infected patients have specific clinic-pathological features that should be further explored to develop new strategies of management and treatment.
Core tip: This is the first study to report the prevalence of Epstein-Barr virus (EBV)-associated gastric carcinomas (EBVaGC) in Portugal. The EBVaGCs were found in 8.4% of all gastric cancer cases, being more frequent in upper and middle regions of the stomach and among tubular and medullary carcinomas. Patients with EBV-positive tumours also have a significant lower number of regional lymph nodes with metastasis and a tendency for a better prognosis.