Paulo Pinheiro, MD, MSc, PhD, Associate Professor Epidemiology, University of Nevada Las Vegas (NAACCR Committee Member)
Asian Americans are the fastest-growing racial/ethnic group in the United States. In their newly published manuscript, our colleagues at the University of Nevada Las Vegas estimated detailed incidence rates for 17 cancer sites for the six largest Asian subgroups. They utilized data from SEER and NPCR for 2009-2011 from the 8 states with the largest number of Asians in the US (CA, FL, HI, IL, NJ, NY, TX, and WA). Excellent work has already been published on rates for Asian subgroups by McCracken et al. 2007, Miller et al. 2008, and Gomez et al. 2013, among others. So what’s new about this research? Two main things: one, the coverage of the total US Asian population is 68%, larger than in previous studies, including non-SEER cities with many Asians like Chicago, Houston and New York City; and two, by systematically accounting for Asians with unknown subgroup (Asian-NOS), they produced rates that, for the first time, permit direct comparisons between major Asian subgroups – Chinese, Japanese, South Asian, Korean, Filipino, and Vietnamese- as well as between any given Asian subgroup and other populations such as Whites, Blacks and Hispanics. When NOS cases are excluded, the resulting incidence rates are inevitably underestimated.
Jin et al. imputed Asian subgroup for NOS cases based on age, gender, region of residence, and cancer site. While the assumption of proportional distribution according to these variables may not be perfect, it is certainly a step closer to unbiased final estimates for incidence rates for each Asian subgroup. In their methodology they also took into account that for some Asians groups, e.g. Malay, Indonesian, and others, there are no appropriate race fields available other than NOS.
The analyses showed that Asian Americans have a lower cancer risk than non-Hispanic whites, except for nasopharyngeal, liver and stomach cancers. In comparison to non-Hispanic whites and other Asian subgroups, increased risks were observed for colorectal cancer among Japanese, stomach cancer among Koreans, nasopharyngeal cancer among Chinese, thyroid cancer among Filipinos, and liver cancer among Vietnamese. The unique portrayal of cancer incidence patterns among specific Asian subgroups in this study provides a new baseline for future cancer surveillance research.
Read Full Article (The abstract below is from Wiley Online Library)
Abstract
Cancer incidence disparities exist among specific Asian American populations. However, the existing reports exclude data from large metropoles like Chicago, Houston and New York. Moreover, incidence rates by subgroup have been underestimated due to the exclusion of Asians with unknown subgroup. Cancer incidence data for 2009 to 2011 for eight states accounting for 68% of the Asian American population were analyzed. Race for cases with unknown subgroup was imputed using stratified proportion models by sex, age, cancer site and geographic regions. Age-standardized incidence rates were calculated for 17 cancer sites for the six largest Asian subgroups. Our analysis comprised 90,709 Asian and 1,327,727 non-Hispanic white cancer cases. Asian Americans had significantly lower overall cancer incidence rates than non-Hispanic whites (336.5 per 100,000 and 541.9 for men, 299.6 and 449.3 for women, respectively). Among specific Asian subgroups, Filipino men (377.4) and Japanese women (342.7) had the highest overall incidence rates while South Asian men (297.7) and Korean women (275.9) had the lowest. In comparison to non-Hispanic whites and other Asian subgroups, significantly higher risks were observed for colorectal cancer among Japanese, stomach cancer among Koreans, nasopharyngeal cancer among Chinese, thyroid cancer among Filipinos, and liver cancer among Vietnamese. South Asians had remarkably low lung cancer risk. Overall, Asian Americans have a lower cancer risk than non-Hispanic whites, except for nasopharyngeal, liver and stomach cancers. The unique portrayal of cancer incidence patterns among specific Asian subgroups in this study provides a new baseline for future cancer surveillance research and health policy.
The opinions expressed in this article are those of the authors and may not represent the official positions of NAACCR.
