Prognostic Factors in Gastrointestinal Stromal Tumors (GIST): Could Prognostic Nutritional Index (PNI) be a New Prognostic Factor?

Objective: To investigate factors that may affect prognosis in gastrointestinal stromal tumors (GISTs). Study Design: A descriptive study. Place and Duration of Study: Karadeniz Technical University Hospital, Trabzon, Turkey from 2000 to 2019. Methodology: All the patients diagnosed with GIST and followed-up in this centre were included. Those who were not followed-up in this centre were excluded. The Chi-square test for differences between variables in independent groups; and the Kaplan-Meier method for survival rates were used. Results: Median tumor size was larger in patients with recurrence, compared to those without (8cm vs. 5 cm, p <0.001). Recurrence rates were higher with mitosis >= 5 in 50 high-power-fields than with low mitosis (52.6% vs. 23.4%, p = 0.021). Median Ki-67 percentages were higher in patients with recurrence than without (5 vs. 2, p = 0.031). Recurrence rates were higher with necrosis and bleeding than without (57.7% vs. 14.3%, p = <0.001; 50% vs. 13.8%, p = 0.003). Median overall-survival (OS) was shorter in with mitotic counts >= 5 compared to <5 (52.0 vs. 110.0 months, p = 0.051) and with ulceration than without (36.0 vs. 110.0 months, p = 0.017). The groups below (<43.5) and above (>43.5) the median prognostic-nutritional-index (PNI) value were similar in terms of OS and disease-free survival (DFS) (52 vs. 70 months, p = 0.174; 82 vs. 100 months, p = 0.411). Median DFS was shorter with ulceration than without (27 vs. 100 months, p = 0.048). Conclusion: While necrosis, bleeding, ulceration, mitosis, size, and Ki-67 significantly affect the prognosis in GIST, PNI has no significant effect.