THE ROLE OF DIETARY FACTORS IN THE INTESTINAL AND DIFFUSE HISTOLOGIC SUBTYPES OF GASTRIC ADENOCARCINOMA - A CASE-CONTROL STUDY IN THE US

BACKGROUND. The decline of gastric adenocarcinoma in the U.S. and the parallel decrease in the predominance of the intestinal type of gastri c adenocarcinoma may reflect, in part, changes in diet over the last 6 0 years. Because the intestinal and diffuse types of gastric adenocarc inoma may be epidemiologically distinct, the authors hypothesized that different nutritional factors are associated with the different subty pes of gastric adenocarcinoma. METHODS. Ninety-one incident cases with a pathologic diagnosis of gastric adenocarcinoma and 132 cancer free controls were included in this study. AU cases were defined as being e ither the intestinal or diffuse type of gastric adenocarcinoma. Epidem iologic data were collected by a modified National Cancer Institute He alth Habits History Questionnaire. Nutritional and dietary factors wer e analyzed using a logistic regression model. RESULTS. Several dietary factors were significantly associated with both subtypes of gastric a denocarcinoma, including dietary intakes of fiber, oleic acid, potassi um, and fruits. Almost all dietary factors and food groups unique to i ntestinal gastric adenocarcinoma were protective in nature (vitamin B6 , folate, niacin, iron, noncitrus fruits, and raw fruit), except for a high intake of dietary calories, which was a risk factor for intestin al gastric adenocarcinoma. The unique factors found to be protective f or diffuse disease were carbohydrate and Vitamin C intake. CONCLUSIONS . This study suggests that dietary factors contribute to the carcinoge nesis of gastric adenocarcinoma. It also appears that although dietary risk and protective factors are common to both the intestinal and dif fuse types of this malignancy, protective dietary factors may play a m ore important role in preventing the intestinal type of gastric adenoc arcinoma. (C) 1997 American Cancer Society.