Objectives: C-reactive protein (CRP) and neutrophil to lymphocyte ratio (NLR) were independent predictive factors for gastric cancer (GC). Our study was designed to prove the prognostic value of the combination of CRP and NLR (COC-NLR) in GC patients.
Materials and methods: A total of 1,058 GC patients who underwent D2 resection from Sun Yat-Sen University Cancer Center between 2003 and 2013 were included. They were divided into three groups (low: NLR ≤2.5, CRP ≤6.1; medium: NLR >2.5, CRP ≤4.5; high: NLR >2.5, CRP >4.5 or NLR ≤2.5, CRP >6.1) by the random forest method. Survival analysis stratified by COC-NLR groups was performed. 
Results: The mean survival time for each group was: for the low group 75.44 months (95% CI: 72.48–78.40), the medium group 56.50 months (95% CI: 50.68–62.31), and the high group 38.65 months (95% CI: 34.51–42.97). The low group showed obviously better overall survival (OS) than other two groups (p <0.001). Survival analysis showed that COC-NLR had statistical significance in both univariate and multivariate analyses (p <0.01).
Conclusion: This study showed that COC-NLR could work as an independent prognostic factor in GC and provide more accurate prediction than single NLR or CRP.
Keywords: inflammation index, NLR, CRP, combination, prognosis, gastric cancer