BACKGROUND
Gastric carcinoma with lymphoid rich stroma (GCLRS) is an undifferentiated gastric carcinoma with heavy lymphocytic infiltrate. In order to clarify the relationship between lymphocytic infiltration and apoptosis in gastric carcinoma, we investigated the association of apoptosis with apoptotic proteins and Epstein-Barr Virus (EBV) expression in GCLRS.
METHODS
We performed immunohistochemical stains for bcl-2, bax and in situ hybridization for EBER (Epstein-Barr virus encoded RNA)-1 and the terminal deoxynucleaotidil transferase mediated dUTP-digoxigenin nick end labelling (TUNEL) technique using 47 out of 1635 gastric carcinoma cases.
RESULTS
The prevalence of GCLRS was 1.47% (24/1635). The prevalence of EBV involvement in GCLRS (79%, 19/24) was significantly higher than that of gastric carcinoma with lymphoid poor stroma (GCLPS) (8.7%, 2/23). The immunohistochemical stain for bcl-2 revealed negative expressions in all cases, but that of bax was positive for in all cases. bax was significantly correlated with the apototic index (P<0.05). There was no statistical significance between lymphocytic infiltration and apoptosis.
The lymphocytic infiltration significantly correlated with the expression of EBV (P<0.05) but not with survival rate and apoptosis. However, most of the GCLRS displayed low clinical stages(stage IA, B), and we suggest that was a proper reason for a good prognosis.
CONCLUSIONS
These results support that EBV is associated with GCLRS, and there is no relationship between apoptosis and bcl-2, bax and prognosis. They also suggest that EBV infection play an important role in the gastric carcinogenesis.