Disaggregated colorectal cancer mortality among Asian American subgroups between 2005-2020.

Background: Colorectal cancer (CRC) is the second-leading cause of cancer death in Asian Americans. Asian Americans are a diverse, heterogenous population composed of groups with differing cancer risk factors. Few prior studies have analyzed CRC mortality by disaggregated Asian racial subgroup.

Methods: Using 2005-2020 US national mortality records linked to American Community Survey one-year population estimates, we report age-standardized mortality rates per 100,000 person-years, standardized mortality ratios (SMR), and average annual percent change trends for the six largest Asian subgroups in a serial, cross-sectional study design. We compared these rates with Non-Hispanic Whites (NHWs). We stratified rates by sex, nativity, and CRC location (colon vs. rectum).

Results: Asian subgroups demonstrated substantial heterogeneity in CRC mortality. Relative to the NHW group, Asian Indian Americans had the lowest rate (female SMR 0.3, 95% CI 0.3-0.3; male SMR 0.3, 95% CI 0.3-0.3) and Japanese Americans the highest rate (female SMR 0.9, 95% CI 0.8-0.9; male SMR 0.9, 95% CI 0.9-1.0). Chinese, Filipino, Korean, and Vietnamese Americans demonstrated mortality between Asian Indian and Japanese. Over the study period, most Asian subgroups had stable or decreasing mortality. However, both Korean and Vietnamese CRC mortality increased over the period. By the end of the study period Korean Americans had the highest CRC mortality of any Asian subgroup.

Conclusions: Asian subgroups demonstrate heterogeneity in patterns of CRC mortality, emphasizing the necessity of disaggregation in cancer research.

Impact: Our study provides disaggregated Asian subgroup CRC mortality data, which may allow for targeted risk attenuation efforts.