392 Background: The overall incidence of colorectal cancer (CRC) has been decreasing since 1998, but there has been an apparent rise in the incidence of CRC in young adults. The primary aim of this study was to evaluate age-related disparities in secular trends in CRC incidence in the United States. Methods: A retrospective cohort study was performed using the Surveillance, Epidemiology, and End Results (SEER) registry. All patients diagnosed with colon or rectal cancer from 1975 to 2010 was queried. SEER*Stat (version 8.04, National Cancer Institute) was used to obtain the annual cancer incidence rates, annual percent change (APC), and corresponding p values for the secular trends. Results: Overall age-adjusted CRC incidence decreased by 0.92% between 1975 and 2010. There has been a steady decline in the incidence of CRC in patients age 50 years or older, but the opposite trend has been observed in patients 20 to 34 years of age. The APC for patients with localized, regional, and distant colon cancer at diagnosis in the 20 to 34 year age group was 1.10 (95% CI 0.28 to 1.93; p=0.01), 0.91 (95% CI 0.23 to 1.61; p=0.01) and 1.81 (95% CI 0.88 to 2.75; p<0.001). The APC for patients with localized, regional ,and distant rectal cancer in the 20 to 34 year age group was 4.03 (95% CI 3.02 to 5.05; p<0.001), 3.05 (95% CI 1.95 to 4.17; p<0.001) and 2.66 (95% CI 1.33 to 3.99; p<0.001). Based on current trends, in 2030 the incidence rate for colon and rectal cancer will increase by 90% and 124.2% respectively for patients 20 to 34 years of age while decreasing by 37.8% and 34.3% for patients 50 to 75 years of age. Conclusions: There has been a significant increase in the incidence of CRC diagnosed in patients age 20 to 34, with a decline in older patients. Further studies are needed to determine the cause for these trends and identify potential preventive and early detection strategies. [Table: see text]