[667] The Type of Host Inflammatory Immune Response Predicts Survival in EBV-Associated Gastric Carcinomas: A Multivariate Analyses of 109 Cases

HJ Song, JH Noh, M Joo, KT Jang, CK Park, KM Kim. Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Ilsan Paik Hospital, Inje University School of Medicine, Seoul, Korea

Background: Epstein-Barr (EB) virus is detected in about 10% of gastric carcinomas (GCs) and the association between EBV infection and GC is well established. Most EBV-associated GCs are lymphoepithelioma-like carcinoma (LELC), but 6.9% to 16% are ordinary adenocarcinomas. EBV-associated GCs tend to be proximally located, of the diffuse subtype, and have lower frequency of lymph node metastasis. The aim of this study was to explore the relationship between host inflammatory immune response and prognosis in EBV-associated GCs.
Design: 109 EBV-associated GCs were evaluated by EBV in-situ hybridization. The pathologic features, TNM stage, metastatic lymph node ratio (LNR; total positive LNs / total LNs examined), disease-free survival, and overall survival were analyzed. Overall and disease-free survivals were calculated using the Kaplan-Meier method.
Results: EBV-associated GCs revealed three pathologic subgroups; typical LELC with prominent lymphoid stroma (n=54), carcinoma with lymphoid follicles simulating Crohn-like reaction (CLR) (n=42), and ordinary adenocarcinoma (n=13). LELCs were associated with less frequent lymphatic invasion, more frequent perineural invasion, lower T and N stages and LNR compared to GCs with CLR or ordinary adenocarcinomas (p<0.05). Upon univariate analyses, histologic subtype (LELC), lower LNR and T and N stages were all closely associated with longer disease-free survival and overall survival (p<0.000). Upon multivariate analyses, histologic subtype (p=0.001, hazard ratio 4.075) and T stage (p=0.001, hazard ratio 3.126) were independent prognostic factors.
Conclusions: EBV-associated GCs have three distinct histologic subtypes and these subtypes were closely associated with prognosis. Our results indicate that the prognosis of EBV-associated GCs may be related to the type of host immune response to EBV.
Category: Gastrointestinal

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 107, Monday Morning