Chronic gastritis profiles in sibs of probands calculated to carry a highly increased risk of gastric carcinoma.

Of 1161 subjects consisting of 4 family samples (gastric carcinoma patient relatives, pernicious anaemia, duodenal ulcer and control families) 18 subjects representing 17 families had distinct atrophic changes in the gastric mucosa that were considered on the basis of risk calculations to carry an at least 7-fold risk to develop gastric carcinoma. Twelve of these 18 subjects could be used as probands and their 41 sibs were subjected to a closer statistical analysis. Sibs of probands having a very high relative risk of gastric carcinoma (18-fold or more) differed markedly from the general population. All sibs had some form of atrophic gastritis and there was a significantly higher than expected prevalence of subjects with severe corpus mucosal atrophy. It is concluded that sibs of subjects with severe atrophic changes may carry an increased risk of gastric malignancy.