We aimed to establish and externally validate a nomogram to predict the 3- and 5-year overall survival (OS) of gastric cancer (GC) patients after surgical resection. A total of 6543 patients diagnosed with primary GC during 2004–2016 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. We grouped patients diagnosed during 2004–2012 into a training set (n = 4528) and those diagnosed during 2013–2016 into an external validation set (n = 2015). A nomogram was constructed after univariate and multivariate analysis. Performance was evaluated by Harrell’s C-index, area under the receiver operating characteristic curve (AUC), decision curve analysis (DCA), and calibration plot. The multivariate analysis identified age, race, location, tumor size, T stage, N stage, M stage, and chemotherapy as independent prognostic factors. In multivariate analysis, the hazard ratio (HR) of non-cardia invasion was 0.762 (P < 0.001) and that of chemotherapy was 0.556 (P < 0.001). Our nomogram was found to exhibit excellent discrimination: in the training set, Harrell’s C-index was superior to that of the 8th American Joint Committee on Cancer (AJCC) TNM classification (0.736 vs 0.699, P < 0.001); the C-index was also better in the validation set (0.748 vs 0.707, P < 0.001). The AUCs for 3- and 5-year OS were 0.806 and 0.815 in the training set and 0.775 and 0.783 in the validation set, respectively. The DCA and calibration plot of the model also shows good performance. We established a well-designed nomogram to accurately predict the OS of primary GC patients after surgical resection. We also further confirmed the prognostic value of cardia invasion and chemotherapy in predicting the survival rate of GC patients.

中文翻译：

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基于贲门浸润和化疗的新型列线图预测胃癌患者术后总生存期

我们旨在建立并外部验证列线图以预测胃癌 (GC) 患者手术切除后的 3 年和 5 年总生存期 (OS)。从监测、流行病学和最终结果 (SEER) 数据库中收集了 2004 年至 2016 年期间诊断为原发性 GC 的 6543 名患者。我们将 2004-2012 年诊断的患者分组为训练集（n = 4528），将 2013-2016 年诊断的患者分组为外部验证集（n = 2015）。在单变量和多变量分析后构建列线图。通过 Harrell 的 C 指数、接受者操作特征曲线下的面积 (AUC)、决策曲线分析 (DCA) 和校准图来评估性能。多变量分析将年龄、种族、位置、肿瘤大小、T 分期、N 分期、M 分期和化疗确定为独立的预后因素。在多变量分析中，非贲门侵犯的风险比（HR）为 0.762（P < 0.001），化疗的风险比（HR）为 0.556（P < 0.001）。发现我们的列线图表现出极好的辨别力：在训练集中，Harrell 的 C 指数优于第 8 届美国癌症联合委员会 (AJCC) TNM 分类（0.736 对 0.699，P < 0.001）；C 指数在验证集中也更好（0.748 对 0.707，P < 0.001）。3 年和 5 年 OS 的 AUC 在训练集中分别为 0.806 和 0.815，在验证集中分别为 0.775 和 0.783。模型的 DCA 和校准图也显示出良好的性能。我们建立了一个精心设计的列线图来准确预测手术切除后原发性 GC 患者的 OS。