Very low risk of lymph node metastasis in Epstein-Barr virus-associated early gastric carcinoma with lymphoid stroma.

BACKGROUND

Epstein-Barr virus-associated early gastric carcinoma with lymphoid stroma (EBV-GCLS) is a rare variant of early gastric carcinomas. Clinicopathological features of this variant remain obscure, especially in Chinese patients. Therefore, we collected EBV-GCLS cases and studied clinicopathology and prognosis.

METHODS

By a retrospective review of 595 consecutive radical gastrectomies for early gastric carcinoma from 2006 to 2018, we identified 8 (1.3%, 8/595) EBV-GCLS cases. Clinicopathologic characteristics were compared between EBV-GCLSs and 109 conventional early gastric carcinomas, which were divided into intramucosal, SM1, and SM2 subgroups. The latter 2 subgroups were classified according to the submucosal invasion depth below or over 500 μm.

RESULTS

All 8 EBV-GCLSs occurred in male patients and invaded deep submucosa (SM2) without lymph node metastasis (LNM), four (50%) of which had synchronous non-gastric malignant tumors (3 gastric gastrointestinal stromal tumors and 1 primary clear cell renal cell carcinoma), and four (50%) arose in the proximal stomach. Compared to conventional early gastric carcinomas, EBV-GCLS was significantly more frequent with SM2 invasion, poor differentiation, and synchronous non-gastric carcinoma tumor, but not with age, gender, macroscopic type, location, size, perineural invasion, lymphovascular invasion, and pathologic stage. In invasion-depth stratified comparisons in the SM2 subgroup, the frequency of LNM in EBV-GCLS was significantly lower than that in conventional early gastric carcinomas (p < 0.05) and the 5-year survival rate of patients with EBV-GCLS was better than that with conventional early gastric carcinomas in 3 subgroups (100% vs 91.5, 85.7, 83.9%, respectively), although the differences did not reach a statistically significant level due to the small sample size. Significant differences among 4 subgroups were found in tumor grade, lymphovascular invasion, LNM, pathological stage, and synchronous tumor, but not in age, gender, macroscopic type, tumor size, location, perineural invasion.

CONCLUSIONS

Even with poor differentiation and SM2 invasion, EBV-GCLS showed very low risk of LNM and may be a candidate for endoscopic therapy such as endoscopic submucosal dissection.