Diet and cancer of the stomach: a case-control study in Greece

A case-control study focusing on the role of diet in the etiology of gastric cancer was undertaken in Piraeus, the sister city of Athens, in a population characterized by ethnic homogeneity but substantial heterogeneity with respect to dietary habits. The case series consisted of 110 consecutive patients with histologically confirmed adenocarcinoma of the stomach, admitted to two teaching hospitals during a 3-year period; the control series consisted of orthopedic patients admitted to a nearby hospital for accidents, fractures and other orthopedic disorders, during the same time period. Dietary histories concerning the frequency of consumption (per month or per week) of about 80 food items were obtained by the same interviewer. Cases reported significantly less frequent consumption of lemons, oranges, brown bread, and raw, salad-type vegetables (particularly lettuce, onions and cucumbers) and, independently, significantly more frequent consumption of pasta, beans and nuts. A relative risk of about 40 was found between extreme quintiles when the above 9 food items were combined in a linear risk score. Use of an index constructed from the study material will clearly overestimate the level of risk between the extreme quintiles, but nevertheless the risk differences appear noteworthy, and consistent with the international variation in the incidence of gastric cancer. No significant associations were found with alcoholic beverages, coffee or tea.