Environmental factors related to Epstein-Barr virus-associated gastric cancer in Japan

Epstein-Barr virus (EBV)-encoded small RNA can be detected in about 1-17% of gastric carcinomas. To elucidate the lifestyles and other factors related to the EBV-associated gastric carcinoma (EBV-GC), we interviewed 43 EBV-GC cases and 162 non EBV-GC cases in Kagoshima Prefecture, Japan from 1996-2001. We mainly focused on lifestyles predominant among men because of its male predominance. Although the prevalence of smokers in EBV-GC cases was higher than among non EBV-GC cases, the difference was not significant (P=0.131). Frequent drinking of coffee and high-temperature drinks, as well as frequent intake of salty and spicy foods, were more prevalent among EBV-GC cases, but only frequent intake of salty food showed a significant difference between EBV-GC and non EBV-GC cases (P=0.026). In addition, EBV-GC cases tended to be exposed to wood dust and/or iron filings (P=0.068) and tar (P=0.097). These findings, together with a high frequency of EBV-GC among remnant cancers after partial gastrectomy, suggest an association between mechanical injuries to the stomach membrane and the high frequency of EBV-GC. The present study also showed that EBV-GC cases tended to be elder brothers/sisters (P for trend =0.029) suggesting that age at primary infection with EBV may be older in EBV-GC cases than non EBV-GC cases.