Shifts in the Proportion of Distant Stage Early-Onset Colorectal Adenocarcinoma in the United States

Background: Carcinoids, frequently classified as "colorectal 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-yearolds), subsite (colorectal, rectal-only, colon-only), and race [nonpatients. 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