The relationship between C-reactive protein to lymphocyte ratio and malignant tumors: a national population-based analysis of NHANES 1999–2010

The inflammatory process can influence various steps in tumorigenesis and is considered the seventh hallmark of cancer. The C-reactive protein-to-lymphocyte ratio has been identified as a novel inflammatory biomarker. However, the association between the C-reactive protein-to-lymphocyte ratio and malignancy among adults remains unclear. We designed this cross-sectional study to explore the association of the C-reactive protein-to-lymphocyte ratio with malignancy among U.S. adults. Participants were drawn from the 1999–2010 cycles of the National Health and Nutrition Examination Survey (NHANES). The C-reactive protein-to-lymphocyte ratio (CLR) was divided into tertiles, with the lowest tertile (L) representing the lowest CLR values and the highest tertile (H) indicating the highest values. To explore the relationship between CLR and malignancy, weighted logistic regression models were employed. Additional subgroup analyses were conducted to support the robustness of the results. A total of 2,540 participants with confirmed malignancies aged ≥ 18 years were enrolled. There is a positive correlation between the C-reactive protein-to-lymphocyte ratio and malignancy. According to the crude model, the highest C-reactive protein-to-lymphocyte ratio was significantly associated with an increased risk of malignancy (Odds ratio: 1.73, 95% CI: 1.56, 1.92). According to the fully adjusted model, the C-reactive protein-to-lymphocyte ratio was significantly associated with the risk of malignancy (P < 0.05), with a 1.23-fold greater risk of malignancy for subjects in the high C-reactive protein to lymphocyte ratio tertile than for those in the lowest C-reactive protein to lymphocyte ratio tertile (low). When the C-reactive protein to lymphocyte ratio tertile increased, we observed significant increasing trends. Interaction tests revealed that the effect of C-reactive protein to lymphocyte ratio on malignancy was significantly affected by alcohol intake (P for interaction = 0.03). Using data from the National Health and Nutrition Examination Survey, this study revealed that there was a positive correlation between the C-reactive protein-to-lymphocyte ratio and malignancy. Our findings highlight that C-reactive protein to lymphocyte ratio may be a potential adverse effect for patients with malignancies. More well-designed studies are still needed to validate our findings in the future.