CANCER INCIDENCE IN THE HMONG OF CENTRAL CALIFORNIA, UNITED-STATES, 1987-94

The Hmong are an ethnic minority in China, some of whom migrated to th e mountainous areas of North Vietnam, Laos, and Thailand in the 19th a nd 20th centuries. Because of their support for the United States duri ng the Vietnam war, many Laotian Hmong fled to Thailand and eventually were re-settled in the US after the end of that conflict. Approximate ly 100,000 Hmong currently live in the US, of whom about half reside i n the Central Valley of California, The purpose of this study was to m easure cancer incidence in this unique new immigrant population. Using the resources of the Cancer Registry of Central California (CRCC), a population-based cancer registry cancer incidence in the Hmong was eva luated by calculating age-adjusted incidence rates as well as by calcu lating proportional incidence ratios. Compared with all races combined , elevated rates of cancer in the Hmong were observed for the followin g sites: nasopharynx, stomach, liver, pancreas, leukemia, and non-Hodg kin's lymphoma. Cervical cancer incidence overall was elevated, but mo re noteworthy, invasive cervix cancer rates were much higher than expe cted. Lower cancer rates were found for breast, prostate, and colorect al cancer. Hmong also experienced advanced stage and grade of disease at diagnosis for many cancer sites in addition to cervical cancer, whi ch may be explained by cultural factors, including avoidance of Wester n medical care and low rates of participation in screening programs. T his population should be followed closely and monitored for patterns o f cancer incidence in the future since it provides a natural laborator y for studies of cancer etiology as this population gradually becomes acculturated to the Western lifestyle.