Background: Carcinoids, frequently classified as “colorectal cancer” contribute to rising early-onset colorectal cancer (EOCRC) incidence rates (IR) and have distinct staging distributions compared to often advanced stage adenocarcinomas (screening target). Thus, assessing temporal shifts in early-onset distant stage adenocarcinoma can impact public health.

Methods: 2000–2016 Surveillance Epidemiology and End Results (SEER) 18 yearly adenocarcinoma IRs were stratified by stage (in situ, localized, regional, distant), age (20–29, 30–39, 40–49, 50–54-year-olds), subsite (colorectal, rectal-only, colon-only), and race [non-Hispanic whites, non-Hispanic Blacks (NHB), Hispanics] in 103,975 patients. Three-year average annual IR changes (pooled 2000–2002 IRs compared with 2014–2016) and cancer stage proportions (percent contribution of each cancer stage) were calculated.

Results: Comparing 2000–2002 with 2014–2016, the steepest percent increases are in distant stage cancers. Colon-only, distant adenocarcinoma increased most in 30–39-year-olds (49%, 0.75/100,000→1.12/100,00, P < 0.05). Rectal-only, distant stage increases were steepest in 20–29-year-olds (133%, 0.06/100,000→0.14/100,000, P < 0.05), followed by 30–39-year-olds (97%, 0.39/100,000→0.77/100,000, P < 0.05) and 40–49-year-olds (48%, 1.38/100,000→2.04/100,000, P < 0.05). Distant stage proportions (2000–2002 to 2014–2016) increased for colon-only and rectal-only subsites in young patients with the largest increases for rectal-only in 20–29-year-olds (18%→31%) and 30–39-year-olds (20%→29%). By race, distant stage proportion increases were largest for rectal-only in 20–29-year-old NHBs (0%→46%) and Hispanics (28%→41%). Distant colon proportion increased most in 20–29-year-old NHBs (20%→34%).

Conclusions: Youngest patients show greatest burdens of distant colorectal adenocarcinoma. Although affecting all races, burdens are higher in NHB and Hispanic subgroups, although case counts remain relatively low.

Impact: Optimizing earlier screening initiatives and risk-stratifying younger patients by symptoms and family history are critical to counteract rising distant stage disease.