本研究旨在调查术后第3天（POD 3）和第5天（POD 5）前降钙素原（PCT）在胃腺癌（GA）患者术后预后中的预测价值，该研究是根据前瞻性双中心研究扩展队列中的患者实施了根治性胃切除手术。在湖南肿瘤医院接受手术的连续GA患者被纳入训练队列，武汉联合医院的患者被纳入外部验证队列。通过使用X-tile确定训练队列中PCT在总生存期（OS）方面的最佳截断浓度。使用单变量和多变量Cox回归分析确定了OS的独立预测因子。此外，分别在验证队列和倾向得分匹配队列中阐明了升高的PCT的预测价值。训练队列中PCT在OS方面的最佳截断浓度为POD 3时为0.67 ng/ml，POD 5时为0.39 ng/ml（n = 906）。POD 5时PCT浓度较高（≥0.39 ng/ml）的患者无论是否出现术后感染，预后均明显较差。此外，在那些PCT浓度升高和感染存在的患者中，确认了一种协同影响。多变量分析证实，在训练队列（HR：1.422，95% CI 1.041-1.943，P = 0.027）、验证队列（n = 297，HR：2.136，95% CI 1.073-4.252，P = 0.031）和匹配队列（n = 901，HR：1.454，95% CI 1.104-1.914，P = 0.008）中，POD 5时PCT浓度≥0.39 ng/ml与较差的生存显著相关。POD 5时PCT浓度≥0.39 ng/ml是胃切除术中GA患者较差预后的可靠预测指标。© 2023. 作者（们）。

The aim of this study was to investigate the predictive value of procalcitonin (PCT) on post-operative day (POD) 3 and 5 for the prognosis of gastric adenocarcinoma (GA) patients who underwent radical gastrectomy surgery in extended cohort from a prospective bi-center study.Consecutive GA patients who received surgery in the Hunan Cancer Hospital were enrolled as the training cohort, and those from Wuhan Union Hospital were included as external validation cohort. The optimal cutoff concentration of PCT for overall survival (OS) in the training cohort was determined by X-tile. The independent predictive factors for OS were identified using univariate and multivariate Cox regression analyses. Furthermore, the predictive value of elevated PCT was clarified in the validation cohort and propensity score matched cohort, respectively.The optimal cutoff concentrations of PCT for OS were 0.67 ng/mL at POD 3 and 0.39 ng/mL at POD 5 in the training cohort (n = 906). Patients with higher PCT concentrations (≥ 0.39 ng/mL) at POD 5 had a significantly worse prognosis whether developing post-operative infections or not. Moreover, a synergistic influence was confirmed in those with elevated PCT concentration and infections. Multivariate analyses confirmed that PCT concentration ≥ 0.39 ng/mL at POD 5 was significantly associated with poorer survival in training cohort (HR: 1.422, 95% CI 1.041-1.943, P = 0.027), validation cohort (n = 297, HR: 2.136, 95% CI 1.073-4.252, P = 0.031) and matched cohort (n = 901, HR: 1.454, 95% CI 1.104-1.914, P = 0.008), separately.PCT concentration ≥ 0.39 ng/mL at POD 5 was a reliable predictor for poorer prognosis in GA patients undergoing radical gastrectomy.© 2023. The Author(s).