Epidemiology of non-small cell lung cancer in Asian Americans: incidence patterns among six subgroups by nativity.

BACKGROUND: Differences in the epidemiology of lung cancer between Asians and non-Hispanic whites have brought to light the relative influences of genetic and environmental factors on lung cancer risk. We set out to describe the epidemiology of non-small cell lung cancer (NSCLC) among Asians living in California, and to explore the effects of acculturation on lung cancer risk by comparing lung cancer rates between U.S.-born and foreign-born Asians.

METHODS: Age-adjusted incidence rates of NSCLC were calculated for Chinese, Filipino, Japanese, Korean, Vietnamese, and South Asians in California between 1988 and 2003 using data from the California Cancer Registry. Incidence rates were calculated and stratified by sex and nativity. We analyzed population-based tobacco smoking prevalence data to determine whether differences in rates were associated with prevalence of tobacco smoking.

RESULTS: Asians have overall lower incidence rates of NSCLC compared with whites (29.8 and 57.7 per 100,000, respectively). South Asians have markedly low rates of NSCLC (12.0 per 100,000). Foreign-born Asian men and women have an approximately 35% higher rate of NSCLC than U.S.-born Asian men and women. The incidence pattern by nativity is consistent with the population prevalence of smoking among Asian men; however, among women, the prevalence of smoking is higher among U.S.-born, which is counter to their incidence patterns.

CONCLUSIONS: Foreign-born Asians have a higher rate of NSCLC than U.S.-born Asians, which may be due to environmental tobacco smoke or nontobacco exposures among women. South Asians have a remarkably low rate of NSCLC that approaches white levels among the U.S.-born. More studies with individual-level survey data are needed to identify the specific environmental factors associated with differential lung cancer risk occurring with acculturation among Asians.