Social Determinants Associated with the Rising Incidence of Early-Onset Colorectal Cancer in the U.S.: A PRISMA Systematic Review

Objectives To examine the behavioral, socioeconomic, clinical and systemic characteristics of colorectal cancer (CRC) in young adults (19–49 years of age) in the United States (U.S). Methods A systematic literature review was performed using PRISMA methodology. Eleven electronic databases were searched for the extant literature. Study eligibility criteria included colorectal cancer patients in the United States aged 19–49 years. Articles published in peer-reviewed journals in English between January 2009-April 2019 were included. Results Diet, smoking, low physical activity, and gut microbiome changes were identified as modifiable risk factors associated with early-onset colorectal cancer (EOCRC). Racial disparities existed where African American and Hispanic populations had a higher incidence of EOCRC compared to non-Hispanic Whites. Results suggested that delays in EOCRC diagnosis were caused by delays between symptom presentation and appropriate screening. Limitations included use of non-longitudinal cross-sectional analysis, which cannot explain etiologic causes. Conclusions Public health efforts are needed for better adherence to a healthy dietary pattern and increasing physical activity, to bring awareness to young adults and clinicians alike to know the symptoms of EOCRC, and for young people to get screened early in an ethnically-inclusive manner to reduce disparities. Findings suggest more prospective, longitudinal studies need to be conducted and analyzed to study the etiologic factors of EOCRC. Funding Sources The authors have no funding sources to report.