Abstract
Background: Esophageal cancer (EC) is a malignant tumor with dreadful mortality, nomogram is a prognosis tool of great significance in therapeutic guidance and assessment. We aimed to establish a newly-built nomogram for OS prediction of EC patients with radical esophagectomy.Methods: A total of 311 EC patients underwent radical esophagectomy were retrospectively investigated with their survival and demographic and clinicopathological data. Patients were randomly divided into the primary and validation cohorts. The establishment of nomogram was based on Cox hazard regression analysis in primary cohort, the calibration curves and Harrell’s concordance index were performed to verify the predictive accuracy while ROC curves was adopted to reflect the efficacy of nomogram. Kaplan–Meier curves showed the clinical significance of risk classification system and Pearson correlation test was utilized to show the correlation between risk classification system and TNM staging.Results: The median OS and 5-year survival rate are 44 months and 29.8% in primary cohort. In validation cohort, they are 52 months and 27.1%, respectively. In Cox hazard regression analysis, we extracted six independent prognostic factors—age, gender, AGR, PRL, N stage, PNI—to establish the nomogram. The C-index of nomogram is 0.75 in primary cohort and 0.70 in validation cohort. Calibration curves indicated high consistency between accurate and predicted OS in both primary and validation cohorts. ROC curves showed a better efficacy of nomogram compared with AJCC T and N stage. The area under curve (AUC) of primary cohort is 0.801 and 0.727 in validation cohort. Patients in primary cohort were divided into three risk groups according to the nomogram score, the median OS between each group was significantly different. Analogical results were obtained in validation cohort. Furthermore, the risk classification system was strongly correlated to AJCC TNM staging system in total cohort (r2=0.647, P<0.001), and it also demonstrated a better OS prediction efficacy (AUC=0.742).Conclusions: We established a neotype nomogram and a relevant risk classification system with verified accuracy and efficacy in OS prediction of EC patients after radical esophagectomy. They may provide feasible value in prognosis assessment and treatment guidance prospectively.
A novel nomogram and risk classification system predicting radiation pneumonitis in patients with esophageal cancer receiving radiotherapy
