To systematically evaluate the association between peripheral blood neutrophil-to-lymphocyte ratio (NLR) and long-term all-cause mortality in colorectal cancer survivors using data from the National Health and Nutrition Examination Survey (NHANES), providing evidence for clinical prognosis assessment.

This study utilized data from the NHANES spanning 1999 to 2018. A total of 267 adult participants diagnosed with colorectal cancer were included. NLR was calculated based on peripheral blood cell counts. Survival data were obtained by linking to the national death index (NDI), with follow-up extending through December 31, 2019. The primary endpoint was defined as all-cause mortality. Multiple covariates, including age, sex, race, education level, poverty income ratio (PIR), body mass index (BMI), diabetes, and hypertension, were adjusted to evaluate the association between NLR and the prognosis of colorectal cancer patients.

When NLR was analyzed as a continuous variable, in the unadjusted crude model, each 1-unit increase in NLR was associated with a 31% increase in all-cause mortality risk (HR=1.31, 95%CI: 1.15~1.49, P＜0.001). After adjusting for age, sex, and race (Model 1), the HR was 1.27 (95%CI: 1.13~1.43, P＜0.001). After further adjustment for education level and PIR (Model 2), the HR was 1.30 (95%CI: 1.14~1.48, P＜0.001). In the fully adjusted model (Model 3) including BMI, hypertension, and diabetes, the HR was 1.30 (95%CI: 1.40~1.48, P＜0.001).

Elevated NLR is independently associated with an increased risk of all-cause mortality in colorectal cancer survivors. As a simple and low-cost inflammatory marker, NLR may aid in identifying high-risk patients and guiding long-term health management and surveillance strategies for colorectal cancer survivors.