Background:

Young adults diagnosed with colorectal cancer (CRC) comprise a growing, yet understudied, patient population. We estimated five-year relative survival of early-onset CRC and examined disparities in survival by race/ethnicity in a population-based sample.

Methods:

We used the National Cancer Institute’s Surveillance, Epidemiology, and End Results program of cancer registries to identify patients diagnosed with early-onset CRC (age 20-49 years) between January 1, 1992 and December 31, 2013. For each racial/ethnic group, we estimated five-year relative survival, overall and by sex, tumor site, and stage at diagnosis. To illustrate temporal trends, we compared five-year relative survival in 1992-2002 vs. 2003-2013. We also used Cox proportional hazards regression models to examine the association of race/ethnicity and all-cause mortality, adjusting for age at diagnosis, sex, county type (urban vs. rural), county-level median household income, tumor site, and stage at diagnosis.

Results:

We identified 33,777 patients diagnosed with early-onset CRC (58.5% White, 14.0% Black, 13.0% Asian, 14.5% Hispanic). Five-year relative survival ranged from 57.6% (Black patients) to 69.1% (White patients). Relative survival improved from 1992 – 2002 to 2003 – 2013 for White patients only; there was no improvement for Black, Asian, or Hispanic patients. This pattern was similar by sex, tumor site, and stage at diagnosis. In adjusted analysis, Black (aHR 1.42, 95% CI 1.36, 1.49), Asian (aHR 1.06, 95% CI 1.01, 1.12), and Hispanic (aHR 1.16, 95% CI 1.10, 1.21) race/ethnicity were associated with all-cause mortality.

Conclusion:

Our study adds to the well-documented disparities in CRC in older adults by demonstrating persistent racial/ethnic disparities in relative survival and all-cause mortality in patients with early-onset CRC.