Cancer incidence patterns in Koreans in the US and in Kangwha, South Korea

Objective: In the US, Koreans are a rapidly growing group and comprised 10.5% of the total Asian population as of 2000. However, little has been published regarding cancer patterns in this subpopulation. Methods: Using data from the Surveillance, Epidemiology, and End Results program, the California Cancer Registry, and the International Association for Research on Cancer, we compared age-adjusted and age-specific incidence rates for cancers of the prostate, breast, cervix, lung, colon, rectum, stomach, liver, and esophagus in US Koreans with rates of these cancers in residents of Kangwha, South Korea, and in US whites as a reference. Results: While the most frequently diagnosed cancer was lung among US Korean males and breast among US Korean females, it was stomach cancer for both sexes in Kangwha. Rates of prostate, breast, and colon cancer were considerably higher for Koreans in the US than in Kangwha, but were not as high as in whites. Cervical and stomach cancers showed the opposite racial/ethnic pattern, with rates highest in Kangwha, intermediate among US Koreans, and lowest among whites. Rates of rectal cancer in females and esophageal cancer in males were two-times higher in Kangwha than in US Koreans but esophageal cancer rates were similar between US Koreans and whites. Liver cancer rates were similar between Kangwha residents and US Koreans, but nearly 10-times lower among whites. Conclusions: Although these comparisons may have methodologic limitations, including data quality and racial/ethnic misclassification, the differences seen in migrant and native Koreans for some cancers warrant further investigation in this growing subpopulation.