Background: While colorectal cancer (CRC) mortality and incidence are declining in the United States among older adults, this decrease may not be observed among patients under the age of 50. This study examined the characteristics of young-onset CRC among hospital patients by comparing baseline characteristics as well as treatment patterns for patients < 50 years of age to those ≥ 50 years of age. Methods: Data from Sentara hospitals systems were utilized. The sample included patients diagnosed with colorectal cancer in Virginia from January 1, 2008 to December 31, 2016. Baseline characteristics were compared using chi-squares and t-tests. Stratified analyses using the Cochran-Mantel-Haenszel test was used to examine the associations between receipt of cancer therapy by age group while controlling for any differences in stage of diagnosis. The Breslow-Day Test was used to test the homogeneity of the odds ratios. Level of significance was set at p < 0.05. Results: There were 4,505 CRC cases diagnosed at eight Sentara Hospitals in Virginia from 2008 to 2016. Among them, 11.59% (n = 522) were aged 18-49 years old at diagnosis with a mean age of 42.74 (SD= 5.87) years. The results of the bivariate analysis showed a statistically significant difference between patients <50 years of age and those ≥50 of age by race, primary payer, alcohol and tobacco history, Charlson comorbidity index, stage of diagnosis, tumor site, tumor size, and treatment therapy for radiation and chemotherapy. More specifically, compared to their counterpart ≥ 50 years of age, people younger than 50 diagnosed with CRC were more likely to be African American (28.74% vs. 23.71%, p = 0.0086), to own a private insurance (68.49% vs. 27.60%, p<0.0001), or to be uninsured (12.91% vs. 3.82%, p < 0.0001), and interestingly to have never used tobacco products (50.43% vs. 43.75%, p < 0.0001). Most importantly, the young age CRC group had higher prevalence of late-stage diagnostic (68.58% vs. 52.47%, p < 0.0001), and a tumor size bigger than 3 cm (60.54% vs. 51.42, p = 0.0018). The young-onset was also more likely to receive chemotherapy and radiation treatments compared with their older counterparts (p < 0.0001). Stratified analyses, controlling for race showed that being Black and younger than 50 lowers the probability of getting surgery by 0.46 times the probability of surgery if White and younger than 50 years of age [OR = 0.4625 (0.2423, 0.8827)]. Conclusions: This study confirmed that people younger than age 50 diagnosed with CRC are at a higher risk for late stage diagnosis. The study also emphasized that the relationship between age and treatment patterns differed by race. This study is one of few to explore the characteristics and treatment patterns of young patients with CRC in a specific region. The results of this study may serve as a reference for future studies or CRC screening, and for the development of CRC Interventions programs to target the under 50 population.

Citation Format: Georges Adunlin, Hadiza Galadima, Matthew Asare. Characteristics of young-onset colorectal cancer patients and variation of treatment patterns: An analysis of US hospital data [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B130.