Prognostic value of post-operative serum procalcitonin in gastric adenocarcinoma patients undergoing radical gastrectomy: propensity score matching analysis of extended cohort from a prospective bi-center study

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: PCT concentration ≥ 0.39 ng/mL at POD 5 was a reliable predictor for poorer prognosis in GA patients undergoing radical gastrectomy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10120-023-01422-0.