Using the preoperative prognostic nutritional index as a predictive factor for non-cancer-related death in post-curative resection gastric cancer patients: a retrospective cohort study

BACKGROUND: Gastric cancer (GC) is the third leading cause of cancer-related mortality worldwide. Therefore, identifying the predictive factors for surgical morbidity, disease recurrence, and long-term survival is necessary for preventing GC patient mortality. We aimed to evaluate the factors that contribute to the poor prognoses of GC patients. METHODS: In this retrospective cohort study, the data of 182 patients who underwent curative gastrectomy for GC was reviewed. The data included patients’ cancer stage and preoperative prognostic nutritional index (PNI) score. We identified the prognostic factors using a univariate analysis and the multivariable Cox proportional hazards model. The associations between PNI and other clinicopathologic factors for GC were compared via logistic regression analysis. Kaplan-Meier curves were used to evaluate patients’ survival in relation to these factors. The median follow-up period was 3.5 years. Multivariable cumulative incidence method based on Fine and Gray’s method was performed to evaluate the association between non GC-related death and potential prognostic factors. RESULTS: There were significant differences in overall survival (OS) between comorbidities (myocardial infarction: P = 0.040, liver disease: P = 0.017), cancer stages (I vs. II: P = 0.049, I vs. III: P < 0.001), tumor size (P = 0.002), lymphatic vessel infiltration (P < 0.001), serum CA 19–9 (P = 0.024), and PNI scores (P = 0.002). Moreover, only PNI score was determined to be an independent prognostic factor for survival. Furthermore, stage I GC patients with high PNI scores had significantly longer OS than those with low PNI scores (P < 0.001), but these groups were not significantly different in terms of recurrence-free survival (P = 0.756). Stage II and III GC patients showed no significant difference in terms of OS and recurrence-free survival, regardless of PNI scores. Finally, Fine and Gray’s method revealed that PNI score was an independent prognostic factor for non-GC-related death (P < 0.001). CONCLUSIONS: Preoperative PNI is effective in predicting the prognosis of post-curative gastrectomy GC patients and can be used to predict non-GC-related death and the OS of post-curative gastrectomy patients with stage I GC.