Abstract Body (Do not enter title and authors here): Background: Both cancer and cardiovascular disease (CVD) are the leading causes of death worldwide. While previous research showed a relationship between CVD and cancer incidence, limited evidence is available regarding the relationship between inflammation and cancer mortality in CVD patients.
Methods: A prospective cohort study using data from the continuous National Health and Nutrition Examination Survey (NHANES) (1999-2016) merged with Medicare and National Death Index (NDI) mortality data until December 31, 2018. We included CVD individuals with no history of cancer at baseline to investigate the relationship between inflammatory markers, including Neutrophil-to-Lymphocyte ratio (NLR), as the main exposure and cancer mortality as the main outcome.
Results: We included 4,089 adult individuals representing 127,809,316 individuals (47% females, 72% non-Hispanic Whites, and 5% Hispanics). The risk factor analysis (Table) using the competing risk modeling showed that while inflammatory markers did not show significant associations with cancer mortality in the overall analysis, upon stratification by race/ethnicity, NH-Blacks showed higher cancer mortality with higher WBC count (aHR 5.61, 95% CI 1.66-18.91, p=0.007) and NLR (aHR 2.97, 95% CI 1.19-7.42, p=0.02), but lower cancer mortality with higher neutrophil (aHR 0.08, 95% CI 0.01-0.60, p=0.02) and lymphocyte (aHR 0.34, 95% CI 0.15-0.80, p=0.02) counts. Notably, our NH-Blacks showed lower neutrophils at baseline than others which could be explained by a phenomenon called “Benign Ethnic Neutropenia -BEN-” that still brings more complexity when interpreting NLR.
Conclusions: Our study highlights the close relationship between cardiovascular health, inflammation, and cancer mortality. The findings also suggest that race/ethnicity may play a significant role in the relationship between inflammation and cancer mortality among individuals with CVD. Yet, further research is still needed to underpin the biological pathways influencing this relationship.