e23307 Background: The Asian and Pacific Islander (API) population is the fastest growing in the United States, composing nearly 7% of the US population. Although cancer is the second leading cause of death overall in the U.S., it is the leading cause of death in the API population. Despite this, no study has assessed trends in cancer mortality in API individuals in the US. Our aim was to analyze differences and trends in API cancer mortality in the U.S. between 1999 to 2020. Methods: The CDC WONDER database was used to determine mortality statistics for patients, classified as non-Hispanic Asian or Pacific Islander, with cancer (ICD-10 codes C00-C97) as the underlying cause of death between 1999 and 2020. Age-adjusted mortality rates (AAMR) were calculated per 100,000 deaths, and were stratified by cancer type, sex, population density, U.S. census region, and age. Joinpoint regression software was used to identify temporal trends. Average annual percent change (APC) was considered statistically significant if p < 0.05. Results: Between 1999 and 2020, cancer accounted for 305,386 deaths in API individuals. During this period, there was a 30% decrease in mortality due cancer and a decrease in APC of -1.5% (p < 0.05). When stratified by cancer site, the largest decrease in APC was in stomach cancer at -3.7% (p < 0.05), and the largest increase was in uterine cancer at 2.6% (p < 0.05). In 1999, males experienced an overall cancer-related AAMR of 151, 48% higher than females at 103; however, by 2020 these differences reduced, with males having a cancer-related AAMR of 105.6 vs API females of 80.9, a 25% difference. Males experienced a larger decrease in APC (-1.8%, p < 0.05), compared with females (-1%, p < 0.05). Rural populations had the largest cancer-related AAMR (113.0) and largest drop in APC (-2%, p < 0.05), compared with urban groups with a cancer-related AAMR of 106.7 and APC drop (-1.3%, p < 0.05). The highest cancer related AAMRs was seen in lung cancer (24.3 in urban vs 25.4 in rural). Liver-cancer related AAMR was highest in urban populations at 10.4 and lowest in rural populations at 8.2. Western census regions had the highest AAMR at 113.7 with an APC decrease of –1.4% and Southern census regions had the lowest AAMR at 90.5 with an APC decrease of –1.2%. Adults aged > 65 experienced the highest cancer related AAMR at 588.2, and adults aged 25-44 demonstrated the lowest AAMR at 14.7. However, adults aged 25-44 experienced the largest decrease in APC at -2% (p < 0.05), compared with adults aged > 65 at -1.4% (p < 0.05). Conclusions: Our study identifies a significant decrease in cancer mortality in API individuals between 1999 and 2020. The largest decrease seen was in stomach cancer; however, uterine cancer mortality has increased. Notably, liver cancer mortality was higher in urban rather than rural groups. Further studies may examine differences amongst API and other racial groups, and potential sources for the disparities seen amongst API individuals.