Prognostic Value of Combination of Inflammatory and Tumor Markers in Resectable Gastric Cancer.

BACKGROUND: Inflammatory response and tumor marker levels have been shown to correlate with the prognosis in several human tumors. However, only a few studies on these markers have been performed in gastric cancer (GC) patients; the clinical significance of the combined markers is unclear. We aimed to evaluate the role of the combination of preoperative neutrophil-to-lymphocyte ratio (NLR) and carbohydrate antigen 19-9 (CA19-9) for predicting the prognosis of patients with GC. METHODS: This retrospective study included 458 patients who underwent gastrectomy with curative intent between January 2013 and July 2014 in the second hospital of Lanzhou University. Receiver operating characteristic curve (ROC) was performed to determine the cut-off values for biomarkers, and their prognostic values were assessed using the Kaplan-Meier curve. The combined score indicators were established based on the optimal cut-off values, which range from 0 to 2. Prognostic significances for overall survival (OS) were assessed by univariate and multivariate Cox regression analysis. Nomogram was used as a visual supplement for the prognostic score system, and the predictive accuracy and discriminative ability were determined by the concordance index (C-index) and calibration curve. RESULTS: The Kaplan-Meier survival analysis showed that the 1-, 3-, and 5-year OS were 66.2% (n = 303), 42.8% (n = 196), and 40.2% (n = 184) in all 458 patients, respectively. The high NLR (≥1.96), PLR (≥126), CA19-9 (≥27 U/mL), and CEA (≥ 5 ng/mL) were associated with poor prognosis of GC patients. The NLR + CA19-9 score indicator proved to be related to tumor size, lymph node metastasis, vascular invasion, perineural invasion, T stage, N stage, TNM stage, PLR, and CEA in patients with GC and an independent prognostic factor for prediction of 5-year OS (score 1: HR = 1.423, 95%CI: 1.049-1.929, P = 0.023; score 2: HR = 2.740, 95%CI: 1.882-3.990, P < 0.001). NLR + CA19-9 has a better predictive ability than other combined or single score indicators based on inflammation and tumor markers (AUC = 0.662, 95%CI: 0.616-0.705, P < 0.001). Moreover, a nomogram was established by the significant characteristics in the multivariate analysis for OS, which represented high accuracy (C-index = 0.692, 95%CI: 0.675-0.708). CONCLUSION: NLR + CA19-9 can independently predict the overall survival of patients with gastric cancer after surgery. The prognostic nomogram based on NLR + CA19-9 is a convenient, economical, and effective prognostic system for clinical practice.