Infection Of CagA-positive Helicobacter Pylori And The Risk For Cardia And Non-cardia Gastric Cancer In High-risk Area Of China

[Objectives]To study the association between CagA-positive Helicobacter pylori (CagA+ -Hp)infection and gastric cardia/non-cardia cancer.Searching for the risk factors and etiological clues of gastric cardia cancer.[Subjects and methods]1. Subjects The cardia cancer cases(n=114) and non-cardia gastric cancer cases(n=114) were inpatients who were diagnosed with primary cardia cancer and were identified between Apr,2001 and Nov,2001 from five hospitals: First-accessory hospital of Fujian Medical University,Xiehe hospital affiliated Fujian Medical University,Fujian provincial hospital, Tumor hospital of Fujian province and General hospital of Fuzhou. Controls were inpatients in the department of orthopedics from the above hospitals. Each control and non-cardia gastric cancer case was matched reseparately to gastric cardia cancer cases by sex, age(±5y).2. Investigation items and methods A structured questionnaire was administered items face to face to all subjects, which contained questions on soci-demographic characteristics, personal medical history, family history of cancer, life-long smoking habits, tea consumption, alcohol drinking, uses of refrigerator to store foods, and 15 main food items including fruit, raw vegetables, fish juice, salted food and other foods in Fujian province.3. Materials and methods of experiment Serum CagA-Hp IgG antibodies were assayed by enzyme linked immunosorbent assay (ElISA).[Results]Prevalence of CagA+-Hp infection Rate of infection of CagA+-Hp in the patients of gastric cardia cancers, non-cardia gastric cancers and controls was 34.6%,28.6% and 46.2%, respectively. Rate of infection of CagA+-Hp was similar for cases or controls with different sexes, age groups and education levels. This pattern was the same in the cases with differnent occupation, While in the controls we observed significantly different rates of CagA+-Hp infection by occupation- stratified.CagA+-Hp infection and the risk for cardia and non-cardia gastric cancer CagA+-Hp infection was not associated with adenocarcinoma of either the gastric cardia or non-cardia gastric.CagA+-Hp infection–environment interaction analyses No obvious interaction was observed between CagA+-Hp infection and other risk factors on the risk of gastric cancer.Risk factors The risk of gastric cardia cancer was increased among those who diet irregularly,those who drink well water, those who suffered from gastric disease or chronic gastritis and those whose first grade relatives suffered from cancer. The risk rose with increasing dose and duration of smoking among current smokers. An inverse association were observed with the consumption of poultry,milk and milk powder,raw fruit,piped water and years of conservation of food in refrigerator.[Conclusions]1. CagA+-Hp infection was not associated with adenocarcinoma of either gastric cardia or non-cardia gastric.2. There maybe different etiologies and risk factors between cardia and non-cardia gastric cancer.