Epidemiological study of EBV-associated gastric carcinoma

为阐明EB病毒(EBV)阳性和阴性胃癌患者环境因素的差异，我们于1996~1997年在日本鹿儿岛县进行了一项问卷调查。本研究的研究对象为28例EBV阳性和60例EBV阴性的胃癌。对于每个EBV阳性病例，男性2例EBV阴性病例和女性3例EBV阴性病例按性别和年龄(/-5岁)匹配。所有受试者都被问及兄弟姐妹的数量、出生顺序、吸烟和饮酒习惯、饮料摄入量、其他饮食因素和职业。我们对Logistic回归模型中的数据进行了分析，发现出生顺序或吸烟习惯的持续时间与EBV相关性胃癌的风险有关。在出生顺序较晚的人群中，EBV阳性病例的优势比(OR)降低。有五个或更多兄弟姐妹的人的风险几乎是四个或更少兄弟姐妹的风险的一半，但OR在统计学上没有显著意义。吸烟超过40年的人与吸烟不足20年或从不吸烟的人相比，OR为6.1。然而，吸烟者/戒烟者的患病率和吸烟剂量与EBV阳性病例的风险无关。本研究的结果表明，EBV感染的年龄可能与EBV相关性胃癌的发生有关。

To clarify the difference of environmental factors between Epstein-Barr virus (EBV) positive and negative gastric carcinoma cases, we conducted a questionnaire survey in Kagoshima Prefecture, Japan, from 1996 to 1997. The subjects in the present study were 28 EBV-positive and 60 EBV-negative gastric carcinoma cases. For each EBV-positive case, 2 EBV-negative cases in males and 3 EBV-negative cases in females were matched by sex and age (+/- 5 years old). All subjects were asked the number of siblings, birth order, smoking and drinking habit, intake of beverages, other dietary factors, and occupation. We analyzed the data in the logistic regression models.We found that the birth order or the duration of smoking habit were associated with the risk of EBV-associated gastric carcinoma. The odds ratio (OR) for EBV-positive cases was reduced among persons of late birth order. The risk among persons with five or more siblings was nearly half that among those with four or less, but the ORs were not statistically significant. The OR among persons who have smoked more than 40 years was 6.1 in comparison with persons who have smoked less than 20 year or never smoked. However, the prevalence of smokers/ex-smokers and the dose of cigarettes were not associated with the risk of EBV-positive cases.The findings in the present study indicated that the age at EBV-infection might be related to the development of EBV-associated gastric carcinoma.