Abstract 1171: Ethnic-immigrant disparities in stomach cancer mortality in the United States, 1989-2017
Authors: Singh Gopal K. , Girmay Mehrete , Lee Hyunjung , Liu Lihua , Allender Michelle 
Published: September 2020

Background: Stomach cancer is a leading cause of cancer death in the United States and globally. Previous research has shown significant ethnic and immigrant disparities in stomach cancer mortality, with immigrants and certain ethnic-minority groups such as Asian/Pacific Islanders (APIs), Hispanics, and Blacks/African Americans experiencing increased risks of stomach cancer diagnosis and mortality. Most analyses have, however, focused on broad racial/ethnic groups. Disparities in stomach cancer mortality among API, Hispanic and immigrant subgroups are not well analyzed. This study examines temporal trends and patterns in stomach cancer mortality among 25 major ethnic-immigrant groups in the US.

Methods: Using the national mortality database, we computed age-adjusted stomach cancer mortality rates for overall nativity/immigrant groups and broad racial/ethnic groups from 1989 to 2017. Stomach cancer mortality rates and relative risks were computed for 25 detailed ethnic-immigrant groups for the time period 2010-2014 (N = 43,312 US-born deaths and 8,217 immigrant deaths). Ethnic-nativity specific population estimates were derived from the decennial census and the American Community Survey. Log-linear regression was used to model mortality trends.

Results: Overall nativity/immigrant differentials in stomach cancer mortality increased over time despite a declining mortality trend for both immigrants and the US-born. Compared with the US-born, immigrants had 62% higher stomach cancer mortality in 1989-1991, 89% higher mortality in 1999-2011, 90% higher mortality in 2010-2014, and 106% higher mortality in 2017. Relative risks of stomach cancer mortality increased from 1.52 in 1989-1991 to 1.97 in 2017 for male immigrants and from 1.82 in 1989-1991 to 2.30 in 2017 for female immigrants. In 2010-2014, stomach cancer mortality rates ranged from 1.9 deaths per 100,000 population for Asian Indians and 2.5 for non-Hispanic whites to 11.4 for Koreans and 13.8 for Samoans. Ethnic-immigrant patterns indicate a 10-fold differential in mortality, with the mortality rates ranging from 1.9 for Asian Indian immigrants to 11.0 for Korean immigrants and 18.8 for US-born Koreans. Immigrants had markedly higher mortality rates than the US-born for most racial/ethnic groups, except for Koreans and blacks where the pattern was reversed.

Conclusions: Nativity/immigrant differentials in stomach cancer mortality widened over time because of a slower mortality decline among immigrants compared to the US-born and changing ethnic composition of the immigrant population. Marked disparities in stomach cancer mortality were found, with API subgroups and immigrants generally experiencing higher mortality risks compared to US-born whites. Higher mortality risks among APIs and immigrant groups may reflect higher prevalence of Helicobactor pylori infection and greater intake of salted, pickled, or smoked foods among them.

Citation Format: Gopal K. Singh, Mehrete Girmay, Hyunjung Lee, Lihua Liu, Michelle Allender. Ethnic-immigrant disparities in stomach cancer mortality in the United States, 1989-2017 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1171.