Abstract:
Objective To explore the effect of the peripheral blood platelet-to-lymphocyte ratio (PLR) on postoperative disease-free survival (DFS) in patients with gastric cancer, and to construct a nomogram model to predict postoperative DFS in gastric cancer patients.
Methods A total of 3 112 patients who underwent radical gastrectomy in Shanghai Cancer Center, Fudan University from December 2011 to December 2019 were retrospectively collected and randomly divided into training group (n=2 178) and internal verification group (n=934). A total of 280 patients with gastric cancer in Guangxi Medical University Cancer Hospital from 2010 to 2018 were collected as external verification group. Univariate and multivariate Cox regression analysis were used to screen the risk factors of postoperative DFS in the training group, and a nomogram model was established to predict 1-, 3- and 5-year DFS in patients with gastric cancer. C index and calibration curve were used to evaluate the discrimination and calibration ability of the model. The accuracy of the model was verified by internal verification group and external verification group.
Results Multivariate Cox regression analysis of the training group showed that TNM stagingⅡ-Ⅲ (Ⅱ: HR=1.64, 95%CI 1.29-1.97, P < 0.001; Ⅲ: HR=2.52, 95%CI 2.20-2.82, P < 0.001), carcinoembryonic antigen (CEA) > 5.2 μg/L (HR=1.48, 95%CI 1.12-1.97, P=0.007), peripheral blood PLR > 114.21 (HR=1.34, 95%CI 1.02-1.78, P=0.036) were independent associated factors for postoperative recurrence or metastasis in patients with gastric cancer. The nomogram model was established based on TNM staging, CEA and peripheral blood PLR. The C-index was 0.734 (P=0.013), and the area under curve (AUC) of the model predicting 1-, 3- and 5-year DFS was 0.716, 0.773 and 0.752, respectively. The model also performed well in the internal validation group and the external validation group.
Conclusions Preoperative peripheral blood PLR is an independent factor for predicting postoperative recurrence or metastasis in patients with gastric cancer, and the nomogram model established by PLR, TNM staging and CEA can accurately and efficiently predict postoperative DFS of patients.