Abstract 1190: Comparison of cumulative incidence rates of colorectal cancer among Asians and Pacific Islanders (API) populations in Guam, Hawai'i, and the United States

Abstract

Abstract Background: Colorectal cancer is one of 4 most common cancers on Guam, Hawai'i (HI) and the US. However, incidence rates vary between ethnic groups and location. Objective: The objective of the study was to compare cumulative incidence rates (CIRs) among ethnic groups in Guam, HI, and the US; specifically, Chamorros in Guam, Filipinos in Guam, HI and the US, and Native Hawaiians in HI and the US. CIRs are weighted sums of age-specific incidence rates therefore they can be used for comparisons between populations. They are relatively stable and thus provide a good estimate of cumulative risk of cancer. Methods: This study included all colorectal cancer cases (n=562) reported to the Guam Cancer Registry and all colorectal cancer cases (n=253,782) reported to the Surveillance, Epidemiology, and End Results (SEER) 9-Registry from 2000 to 2014. Cumulative incidence rates were calculated for three time periods: 2000-2004, 2005-2009, and 2010-2014 and compared by age, ethnicity and location. Results: Differences were seen in CIRs by time-period, age, ethnicity, and location. For all three time periods: 2000-2004, 2005-2009, 2010-2014, the lifetime cumulative incidence rates (age 0-79) were highest for Hawai'i (5.7%, 5.4%, and 5.3% respectively), followed by the US (5.2%, 4.5%, and 3.7%) and Guam (4.3%, 3.3%, and 3.6%). Interestingly, there were large differences in lifetime CIRs between Filipinos in HI, Filipinos in the US and Filipinos on Guam (i.e. 6.5%, 3.7%, and 2.4% respectively in 2005-2009). The Chamorros on Guam had the rate at least 1.5 times higher than Filipinos on Guam (4.3 % vs 3.3%) and close to the rate of Native Hawaiians in HI (4.9%). Overall, there was downward trend for the lifetime CIRs over time. Only for the Filipinos in HI, the rates went up. However, early onset CIRs (age 0-49) went up across all locations and ethnic groups. Conclusions: Disparities in colorectal cancer incidence were identified. Further study is needed to examine how exposure to risk factors and screening changes with immigration and how this variation contributes to the incidence disparities. Citation Format: Grazyna Badowski. Comparison of cumulative incidence rates of colorectal cancer among Asians and Pacific Islanders (API) populations in Guam, Hawai'i, and the United States [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 1190.