The increasing incidence of colorectal cancer in younger patients in the United States: Who, what, when, and where?

1573 Background: Prior studies have shown an increase in the rate of colorectal cancer (CRC) in young individuals in the United States. However, few studies have evaluated the health disparities that exist in this population, particularly using large, national cohorts. We examined differences in age, race, stage, region, and tumor location in younger and older patients with CRC. Methods: Data were extracted from the United States Cancer Statistics (USCS) for individuals diagnosed between 2001 and 2014. CRC incidence data among individuals < 50 years old were compared to those > 50 years old. Age-specific and age-adjusted incidences and trend analyses reported as annual percent change (APC) were performed using SEER*Stat and Joinpoint regression. Results: Of 1,886,441 individuals, the overall age-adjusted incidence of CRC decreased from 52.59 (per 100,000) in 2001 to 35.22 in 2014, with an APC of -3.24. Although over 35% cases were diagnosed in the Southern United States, the Northeast had the highest age-adjusted incidence at 45.26 per 100,000 patients. Younger patients were diagnosed with distant disease at 25.8% compared to only 18.4% in older patients. Younger patients were also more likely to have sigmoid or rectal cancers compared to older patients (64.3% vs. 45.7%). Of the 170,244 individuals < 50 years, 90,855 (53.4%) were men and 79,389 (46.6%) were women. The age-specific incidence in this younger cohort increased from 5.63 to 6.48 between 2001-2014, with an APC of +1.24 in 2001-2008 compared to +2.55 in 2012-2014. The incidence of CRC in patients aged 0-29, 30-39, and 40-49 years was 0.41 (per 100,000), 6.08, and 21.09, respectively. Black individuals < 50 years had the highest age-specific incidence of CRC (7.16 per 100,000) compared to Asian (6.43), White (6.07), or Hispanic (4.76) individuals. Conclusions: Our data suggests that CRC is increasing in young patients, particularly for those between 40-49 years and Black individuals. In our younger cohort, CRC was more commonly found in the sigmoid colon and rectum compared to older patients. Further research is warranted to direct resources towards improved colonoscopy or sigmoidoscopy screening for younger patients at risk.