Abstract
Introduction: No effective peripheral blood predictors have been establoshed for first-line chemotherapy in patients with advanced gastric cancer. In this study, a nomogram combining the neutrophil-to-lymphocyte ratio/D-dimer with gender, number of metastases, and histological grade was established to predict progression-free survival in patients with unresectable advanced gastric cancer. Methods: We retrospectively collected baseline clinical characteristics and blood parameters from 153 patients diagnosed with advanced gastric cancer that underwent oxaliplatin-based first-line chemotherapy. Kaplan-Meier analysis and Cox regression analysis were used to determine the factors associated with progression-free survival. The concordance index (C-index) and calibration curve were used to determine the prediction accuracy and discriminative ability of the nomogram as a visual complement to the prognostic score system. Results: Determined by the X-tile software, the optimal cut-off points for the neutrophil-to-lymphocyte ratio and D-dimer were 3.18 and 0.56 mg/L, respectively. Multivariate analysis identified four independent prognostic factors: two or more metastatic organs (HR: 1.562, 95% CI: 1.009-2.418, P = .046), poor differentiation (HR: 0.308, 95% CI: 0.194-0.487, P < .001), neutrophil-to-lymphocyte ratio >3.18 (HR: 1.427, 95% CI: 1.024-1.989, P = .036), and D-dimer >0.56 mg/L (HR: 1.811, 95% CI: 1.183-2.773, P = .006). Receiver operating characteristic curves showed that the combination of the neutrophil-to-lymphocyte ratio and D-dimer in the prediction model exhibited the highest predictive performance (area under the curve, 0.800). The prognostic nomogram yielded a C-index of 0.800. Decision curve analysis demonstrated that the prognostic nomogram was clinically useful. A nomogram-based risk classification system was also constructed to facilitate risk stratification of advanced gastric cancer for optimal clinical management. Conclusion: We identified the neutrophil-to-lymphocyte ratio and D-dimer level as independent prognostic factors for advanced gastric cancer. The prognostic nomogram combining the neutrophil-to-lymphocyte ratio and D-dimer level can be applied in the individualized prediction of treatment outcome in patients with advanced gastric cancer.