Prognostic value of Prognostic Nutritional Index (PNI) for 5-year recurrence-free survival in surgically resected gastrointestinal stromal tumors

BACKGROUND: Recent studies have investigated the role of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic inflammation index (SII), and prognostic nutritional index (PNI) on prognosis for various malig-nancies. However, the value of these markers in determining the prognosis for gastrointestinal stromal tumors (GIST) remains controversial. We investigated the effect of NLR, PLR, SII, and PNI on 5-year recurrence-free survival (RFS) in patients with surgically resected GIST. MATERIALS AND METHODS: We retrospectively analyzed patients (n=47) who had undergone surgical resection for pri-mary, localized GIST at a single institution between 2010 and 2021. The patients were divided into two groups accord-ing to the recurrence status in the 5-year period as 5-year RFS(+) (patients with no recurrence (n=25) and 5-year RFS(-) (patients with recurrence (n=22) groups. RESULTS: In univariate analyses, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), tumor localiza-tion, tumor size, PNI, and risk category were significantly different between the RFS(+) and RFS(-) groups while NLR, PLR, SII were not. Multivariate analyses revealed that only the tumor size (HR =5.485, 95% CI: 0.210-143.266, p=0.016), and PNI (HR= 112.020, 95% CI: 8.755–1433.278, p<0.001) were independent prognostic factors for RFS. The patients with a high PNI (≥46.25) had a higher 5-year RFS rate than the patients with low PNI (<46.25) (95.2% to 19.2%, p<0.001). CONCLUSION: A higher preoperative PNI is an independent positive predictor for 5-year RFS for patients with surgically resected GIST. However, NLR, PLR, and SII have no significant effect.