Chemotherapy and age stratified survival outcomes in colorectal cancer based on a population analysis from the surveillance epidemiology and end results program 2010 to 2020

Chemotherapy conferred a survival benefit in patients aged ≥ 45 years, including the very elderly, when selection was based on functional status rather than age alone, whereas no clear benefit emerged in younger patients. This association persisted after multivariable adjustment and across stage-stratified and sensitivity analyses. Given SEER's lack of regimen, timing, comorbidity, and targeted-therapy detail, cautious interpretation is warranted.