Association between the red cell distribution Width - coefficient of variation with colon cancer and all-cause mortality: insights from the 1999-2018 NHANES.

BACKGROUND: This study examined the link between red cell distribution width - coefficient of variation (RDW-CV) levels, colon cancer, and all-cause mortality in the community population. METHODS: Five thousand one hundred twenty-four participants were included out of 131,030 from the NHANES 1999-2018 survey. Survival differences were analyzed with Kaplan-Meier curves, while multivariate Cox regression, restricted cubic spline models and threshold effect analysis assessed correlations. Subgroup analyses by sex and age were also performed. To ensure the robustness of our findings, sensitivity analyses and the E-value were performed. RESULTS: Over a median follow-up of 12.7 [10.3; 15.4] years, 124 deaths occurred. The KM survival curves showed that the greatest risk for colon cancer (Log-rank p = 0.018) and all-cause mortality (Log-rank p < 0.001) was at RDW-CV 13.4-13.9 (Q3), while the lowest risk for both was at RDW-CV 12.9-13.3 (Q2). Compared to Q1, there was an increased risk of colon cancer (adjusted HR = 2.43, 95% CI 1.32-4.48, p = 0.005) and overall mortality (adjusted HR = 2.88, 95% CI 1.54-5.40, p < 0.001). Adjusted models confirmed a positive association between RDW-CV and both outcomes. Threshold effects associated with RDW-CV and both outcomes were not found. A subgroup analysis revealed no significant interaction between RDW-CV and variables like age and sex for colon cancer and all-cause mortality (all p for interaction > 0.05). Sensitivity analysis indicates that the outcomes are stable. CONCLUSIONS: RDW-CV is significantly associated with both colon cancer and all-cause mortality in community-dwelling individuals, suggesting a positive correlation. RDW-CV may serve as a simple and cost-effective indicator for assessing colon cancer risk and as a straightforward, economical marker for mortality prediction in the community.