BACKGROUND Surgery is the only way to cure gastric adenocarcinoma (GAC), and chemotherapy is the basic adjuvant management for GAC. A significant prognostic nomogram for predicting the respective disease-specific survival (DSS) rates of GAC patients who receive surgery and chemotherapy has not been established. OBJECTIVE We were planning to establish a survival nomogram model for GAC patients who receive surgery and chemotherapy. METHODS We identified 5764 GAC patients who had received surgery and chemotherapy from the record of Surveillance, Epidemiology, and End Results (SEER) database. About 70% (n = 4034) of the chosen GAC patients were randomly assigned to the training set, and the rest of the included ones (n = 1729) were assigned to the external validation set. A prognostic nomogram was constructed by the training set and the predictive accuracy of it was validated by the validation set. RESULTS Based on the outcome of a multivariate analysis of candidate factors, a nomogram was developed that encompassed age at diagnosis, number of regional lymph nodes examined after surgery, number of positive regional lymph nodes, sex, race, grade, derived AJCC stage, summary stage, and radiotherapy status. The C-index (Harrell's concordance index) of the nomogram model was some larger than that of the traditional seventh AJCC staging system (0.707 vs 0.661). Calibration plots of the constructed nomogram displayed that the probability of DSS commendably accord with the survival rate. Integrated discrimination improvement (IDI) revealed obvious increase and categorical net reclassification improvement (NRI) showed visible enhancement. IDI for 3-, 5- and 10- year DSS were 0.058, 0.059 and 0.058, respectively (P > 0.05), and NRI for 3-, 5- and 10- year DSS were 0.380 (95% CI = 0.316-0.470), 0.407 (95% CI = 0.350-0.505), and 0.413 (95% CI = 0.336-0.519), respectively. Decision curve analysis (DCA) proved that the constructed nomogram was preferable to the AJCC staging system. CONCLUSION The constructed nomogram supplies more credible DSS predictions for GAC patients who receive surgery and chemotherapy in the general population. According to validation, the new nomogram will be beneficial in facilitating individualized survival predictions and useful when performing clinical decision-making for GAC patients who receive surgery and chemotherapy.

中文翻译：

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诺法图可预测接受手术和化学疗法的胃腺癌患者的生存情况。

背景技术手术是治愈胃腺癌（GAC）的唯一方法，化学疗法是GAC的基本辅助治疗方法。尚未建立可预测接受手术和化学疗法的GAC患者各自的疾病特异性存活率（DSS）的重要预后诺模图。目的我们正计划为接受手术和化疗的GAC患者建立生存诺模图模型。方法我们从监测，流行病学和最终结果（SEER）数据库中鉴定了5764名接受手术和化疗的GAC患者。大约70％（n = 4034）的所选GAC患者被随机分配到训练集，其余的（n = 1729）被分配到外部验证集。通过训练集构建预后列线图，并通过验证集验证其预测准确性。结果基于候选因素的多变量分析结果，开发出了诺模图，其中包括诊断时的年龄，手术后检查的区域淋巴结数目，阳性的区域淋巴结数目，性别，种族，等级，衍生的AJCC阶段，总结阶段和放疗状态。列线图模型的C指数（Harrell一致性指数）比传统的第七AJCC分期系统的C指数（0.707对0.661）要大一些。所构建的列线图的标定图显示，DSS的概率与存活率相称。综合歧视改善（IDI）显示明显增加，而分类净重分类改善（NRI）显示明显改善。3年，5年和10年DSS的IDI分别为0.058、0.059和0.058（P> 0.05），3年，5年和10年DSS的NRI为0.380（95％CI = 0.316-0.470） ，0.407（95％CI = 0.350-0.505）和0.413（95％CI = 0.336-0.519）。决策曲线分析（DCA）证明，构造的列线图优于AJCC分级系统。结论构造的列线图为一般人群接受手术和化疗的GAC患者提供了更可靠的DSS预测。根据验证，