Prognostic and clinicopathological significance of the Prognostic Nutritional Index in patients with gastrointestinal stromal tumours undergoing surgery: a meta-analysis

OBJECTIVES: Previous studies have investigated the prognostic value of the Prognostic Nutritional Index (PNI) in patients with gastrointestinal stromal tumours (GISTs). However, the results have been inconsistent. We performed a meta-analysis to quantitatively determine the prognostic and clinicopathological significance of PNI in GISTs. DESIGN: This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Pooled HRs and 95% CIs were calculated to estimate the prognostic value of PNI in patients with GISTs. Combined ORs and corresponding 95% CIs were used to evaluate the association between the PNI and clinicopathological characteristics. DATA SOURCES: The electronic databases PubMed, Web of Science, Embase and Cochrane Library were thoroughly searched from inception to December 2021. ELIGIBILITY CRITERIA: A random-effects model or fixed-effects model was selected based on the level of heterogeneity among the included studies. RESULTS: Eight studies comprising 2307 patients were included in this meta-analysis. A low PNI was significantly associated with worse recurrence-free survival (RFS) (HR 2.02, 95% CI 1.66 to 2.47, p<0.001) and overall survival (OS) (HR 4.35, 95% CI 1.25 to 16.83, p=0.033) in patients with GISTs. In addition, a low PNI was significantly associated with tumour size ≥5 cm (OR 1.65, 95% CI 1.21 to 2.24, p=0.002) and primary tumour site in small intestine/colorectum/extra-GISTs (OR 2.03, 95% CI 1.26 to 3.26, p=0.004). CONCLUSIONS: Patients with GISTs and a lower PNI had inferior RFS and OS. Patients with GISTs and a low PNI may have a higher risk of tumour recurrence.