Effects of Socioeconomic Status on Colorectal Cancer Incidence and Clinical Outcome Differences Among Asian American Populations: A Systematic Review.

Colorectal cancer (CRC) is a leading cause of cancer death among Asian Americans and Pacific Islanders (API) in the United States. Race, ethnicity, and socioeconomic status (SES) are known to impact outcomes of CRC, but the relationship is unclear in the context of the Asian American cohort and its diverse subgroups. This systematic review aims to gain insight into the relationship between CRC incidence and clinical outcomes in the Asian American community. A systematic literature search was conducted per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol using PubMed, Scopus, Excerpta Medica database (EMBASE), Cochrane, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science databases, accessed on August 13, 2023. Of the 2225 studies identified, a total of 14 studies were included in the analysis. Four studies concluded that there was no association or variable response subgroup-specific to SES measurements in CRC incidence in the Asian American population. However, there was evidence that the incidence of CRC varies among Asian American subgroups, using varying measures of SES. Seven of the eight studies that measured mortality or survival as the primary outcome found decreased mortality and increased survival in the API population despite changes in SES. Out of the six studies that measured incidence, four studies found no association with SES. A study found that Chinese Americans had a significant decrease in the CRC incidence and mortality across all SES categories. Japanese Americans experienced a significant decrease in the lowest SES category, while Koreans and Filipinos experienced a significant increase in both the lowest and highest SES categories. Therefore, grouping various Asian American ethnicities as a single monolithic "Asian" category is misleading. Although the incidence of CRC was thought to be low and decreasing, this review identified various subgroup-specific trends among 24 different Asian American subsets. For example, there was a decrease in CRC rates in two ethnic groups and an increase in the other two ethnic groups. The potential causes of these varying CRC incidence rates are likely multifactorial and may include inadequate screening rates, lack of CRC education, and cultural barriers. Further studies are needed to understand these mechanisms. This review recommends a more detailed classification of the API ethnic population but not as a single monolithic entity as Asian. It also emphasizes preventative CRC screening within the API communities due to lower rates of CRC screening among them.