Adénocarcinomes de l'estomac et de l'œsophage distal: Incidence et caractéristiques phénotypiques des cas associés au virus Epstein-Barr (EBV) en région lyonnaise

Aims: Our study aimed to evaluate the incidence of EBV-associated adenocarcinomas of the stomach and distal esophagus in Lyons area and to assess their phenotypic characteristics. Methods: 85 cases of gastric adenocarcinomas and 40 cases of esophageal adenocarcinomas were screened for EBV by in situ hybridization (EBER-1 and -2) and immunohistochemistry (LMP1 and EBNA-1); all cases positive for EBER by in situ hybridization were studied by PCR for demonstration of EBV DNA. The clinical, histological and immunophenotypic features of EBV-associated adenocarcinomas were assessed. Results: 5 cases of EBV-associated adenocarcinomas, all gastric, were identified in our series (5.8%): one was diagnosed in a migrant from Algeria, a region of high endemic of EBV infection. 3 cases were located in the proximal stomach, 1 in the distal; 1 was diffuse. 4 cases were of the intestinal histological type. Proliferation index and microvessel density were high in all 5 cases. The expression of tumor markers was markedly heterogeneous from one case to another. Conclusions: Our study shows that EBV infection is restricted to gastric adenocarcinomas. Its incidence is evaluated to 5.8% in our series: this shows that Lyons area must be considered as a low risk area. In the absence of specific histological or phenotypic features, the screening of EBV +gastric adenocarcinomas is possible only with special techniques.