Cancer Incidence in U.S. Immigrant Populations
Between 1975 and 2003, a number of studies were published that compared patterns of cancer incidence in U.S. Caucasians, immigrant groups, and matched controls. The studies used data from SEER, regional cancer registries in the United States, and cancer registries in other countries. Their conclusions have been remarkably uniform.
The studies found that cancer incidence patterns among first-generation immigrants were nearly identical to those of their native country, but through subsequent generations, these patterns evolved to resemble those found in the United States. This was true especially for cancers related to hormones, such as breast, prostate, and ovarian cancer and neoplasms of the uterine corpus and cancers attributable to westernized diets, such as colorectal malignancies. The longer people lived in the United States, the lower their rates of cancers that could be attributed to Asian diets, such as stomach cancer associated with the highly salted and nitrite-containing foods common in Asia; cancers caused by infections, such as liver cancer caused by hepatitis B and C; stomach cancer caused by Helicobacter pylori; cervical cancer caused by human papillomavirus; and cancers caused by specific environmental problems, such as nasopharyngeal cancer associated with exposure to smoke from stoves used for cooking in the home and salivary cancer associated with cold, dark environments that produce vitamin A deficiencies.
The populations studied included first- and second-generation Japanese immigrants living in Hawaii; Asian-American women; Vietnamese-Americans; Hmong refugees from Vietnam, Laos, and Thailand who settled in California; Korean-Americans; Pacific Islanders; and Alaska Natives. All of these studies helped scientists to identify environmental factors that encourage cancer to develop and paved the way for the field of cancer prevention.
Lanier AP, Bender TR, Blot WJ, Fraumeni JF Jr, Hurlburt WB. Cancer incidence in Alaska Natives. Int J Cancer 1976;18:409-412.
Kolonel LN, Hinds MW, and Hankin JH. Cancer patterns among migrant and native-born Japanese in Hawaii in relation to smoking, drinking, and dietary habits. In: Gelboin H.V. et al., eds. Genetic and environmental factors in experimental and human cancer. Tokyo: Japan Sci Soc Press 1980:327-340.
Henderson BE, Kolonel LN, Dworsky R, Kerford D, Mori E, Singh K, Thevenot H. Cancer incidence in islands of the Pacific. J Natl Cancer Inst 1985;69:73-81.
Ziegler RG, Hoover RN, Pike MC, Hildesheim A, Nomura AM, West DW, Wu-Williams AH, Kolonel LN, Horn-Ross PL, Rosenthal JF, Hyer MB. Migration patterns and breast cancer risk in Asian-American women. J Natl Cancer Inst 1993;85:1819-1827.
Le GM, Gomez SL, Clarke CA, Glaser SL, West DW. Cancer incidence patterns among Vietnamese in the United States and Ha Noi, Vietnam. Int J Cancer 2002 102:412-427. Erratum in: Int J Cancer 2003;104(6):798.