Index-window C-reactive protein and carcinoembryonic antigen and five-year all-cause mortality in Hispanic/Latino and non-Hispanic White patients with colorectal cancer: a retrospective biomarker cohort study.

Aims: To examine index-window carcinoembryonic antigen (CEA), C-reactive protein (CRP), and five-year recorded mortality by ethnicity in colorectal cancer.

Patients and methods: This retrospective University of California Health Data Warehouse cohort included Hispanic/Latino and non-Hispanic White adults indexed during 2012-2020 with both biomarkers measured within ±30 days and complete covariates. Linear regression modeled log(CEA + 0.1); Cox regression modeled recorded all-cause mortality.

Results: Among 345 patients, 143 deaths were recorded. Hispanic/Latino ethnicity was associated with higher log(CEA + 0.1) (β = 0.743; robust 95% confidence interval [CI], 0.202-1.285; P = 0.007). The mortality association was nonsignificant (hazard ratio [HR], 0.723; 95% CI, 0.483-1.084; P = 0.117). Higher log(CEA + 0.1) (HR, 1.266; 95% CI, 1.174-1.366; P < 0.001) and log(CRP + 0.1) (HR, 1.134; 95% CI, 1.037-1.239; P = 0.006) were associated with mortality.

Conclusions: In this biomarker-selected cohort, Hispanic/Latino patients had higher recorded CEA without a statistically significant ethnic-group mortality difference. Confirmation requires clinically characterized cohorts with stage, treatment, biomarker timing, verified assay comparability, and complete mortality ascertainment.