ETHNIC VARIATION IN THE INCIDENCE OF STOMACH-CANCER IN ILLINOIS, 1986-1988

Wide ethnic and geographic variation in stomach cancer incidence has b een reported in Eastern and Western countries. Stomach cancer is repor ted to be the most common malignant neoplasm in Asia, specifically, Ch ina, Japan, and Korea. In contrast, stomach cancer incidence in the Un ited States among Caucasians is low and among blacks, moderate to low. Only one other study has directly compared the rates of stomach cance r in the three ethnic groups (i.e., white, African American, and immig rant Korean) living in the same region. The authors extend their inves tigation by comparing the incidence rate of stomach cancer among the s ame three ethnic groups in the state of Illinois from 1986 to 1988. In this study, the incidence of stomach cancer was observed to be lowest in whites, intermediate in African Americans, and highest in immigran t Koreans. The overall 3-year cumulative incidence rate from 1986 to 1 988 was 62.6/100,000 (95% confidence interval (CI) 38.6-86.7), 28.2/10 0,000 (95% CI 25.7-31), and 22.5/100,000 (95% CI 21.5-23.5) for immigr ant Koreans, African Americans, and whites, respectively. The 3-year a ge-adjusted cumulative incidence rate for immigrant Koreans (172/100,0 00) was approximately four- and eightfold higher than for African Amer icans (41/100,000) and whites (21/100,000). The incidence of stomach c ancer increased as a function of age in both sexes, Although a higher rate was observed in males than in females, these rates were four- and eightfold higher in African Americans and immigrant Koreans, when com pared with their white counterparts in both sexes. Despite a substanti al reduction of stomach cancer incidence in the United States and othe r Western countries, it remains the most frequent malignancy in native and immigrant Koreans. The high rate of stomach cancer in immigrant K oreans compared with African Americans and white populations residing in Illinois indicates either a drastically disproportionate undercount of immigrant Koreans in the 1990 census or a profound genetic-environ mental interaction.