Objective:To investigate the risk factors affecting the completion of postoperative adjuvant chemotherapy in elderly patients with progressive gastric cancer.Methods:Clinicopathological data of patients diagnosed with gastric adenocarcinoma and treated with radical surgery at our hospital between January 2017 and December 2018 were retrospectively collected, and 96 patients were finally included in the study according to the inclusion and exclusion criteria.Patients were divided into a completed chemotherapy group and an uncompleted chemotherapy group depending on whether they had completed 6 cycles of adjuvant chemotherapy after surgery.The optimal cut-off value was derived from the receiver operating characteristic(ROC)curve, and the Youden Index was calculated.Relevant factors that might affect the completion of postoperative adjuvant chemotherapy in elderly patients with progressive gastric cancer were included in univariate and multivariate Logistic regression analyses to identify independent risk factors affecting the completion of postoperative adjuvant chemotherapy in gastric cancer patients.The Kaplan-Meier(K-M)method was used to plot the survival curves for the groups, and the log-rank test was used to compare the survival rates between the groups.Results:A total of 96 patients, aged 60-89 years, with a mean age of(70.3±7.0)years, were included.Sixteen patients completed postoperative adjuvant chemotherapy, while 80 patients did not.The following analysis was performed on clinicopathological data of patients in the two groups.Univariate Logistic regression analysis showed that patient age ≥70 years( OR=8.135, 95% CI: 1.735-38.153, P=0.008)or a preoperative prognostic nutritional index(PNI)score <49.5( OR=4.765, 95% CI: 1.549-14.656, P=0.006)affected the completion of postoperative adjuvant chemotherapy.The risk factors that might affect the completion of postoperative adjuvant chemotherapy in elderly gastric cancer patients were analyzed using multivariate Logistic regression and the results showed that age ≥70 years( OR=9.815, 95% CI: 1.947-49.485, P=0.006)and a preoperative PNI score <49.5( OR=5.895, 95% CI: 1.711-20.305, P=0.005)were independent risk factors hindering the completion of postoperative adjuvant chemotherapy. Conclusions:Age ≥70 years and PNI<49.5 are independent risk factors for the completion of postoperative adjuvant chemotherapy.Failure to complete postoperative adjuvant chemotherapy is associated with a poor prognosis.PNI is a valid predictor for whether postoperative adjuvant chemotherapy will be completed and helps to screen chemotherapy patients who need nutritional intervention.