Life-style and subsite of gastric cancer--joint effect of smoking and drinking habits.

To clarify the effects of life-style on gastric cancer by subsite focusing on the proximal part (cardia and fundus) and the distal part (pyloric antrum), a case-control study was conducted at the Aichi Cancer Center in Nagoya, Japan from 1988-1991. This study compared 668 histologically confirmed gastric cancer cases [123 cardia, 218 middle (body), 256 antrum, and 71 unclassified] with 668 controls using a common questionnaire about life-styles as related to smoking, drinking, dietary habits and frequency of food intake. Controls were selected from among outpatients of the same hospital. Controls free of cancer and other specific diseases were matched with cases for sex, age (within 2 years), and time of hospital visit (within 2 months). A Western-style breakfast decreased the risk of antrum cancer, while consumption of greasy food increased the risk of cardia cancer. Fresh vegetables decreased the risk of cancer in both cardia and antrum. Habitual smoking is associated with increased risk of gastric cancer and it is more prominent in cardia cancer, especially in those who are drinkers. Results obtained from this study suggest that risk factors and relative risks of gastric cancer varied by subsite to a considerable degree. Furthermore, the joint effect of smoking and drinking may play an important role in the development of gastric cancer, especially of cardia cancer.