The effect of clinicopathological characteristics on recurrence and survival in patients operated for gastroenteropancreatic neuroendocrine tumors

Aim: Gastroenteropancreatic neuroendocrine tumors (GEP-NET) are rare neoplasms of the gastrointestinal tract and pancreas. This study aims to investigate the relationship between clinicopathological characteristics of patients operated for GEP-NET and tumor recurrence and overall survival. Material and Method: A total of 79 GEP-NET patients operated between 2016 and 2023 were retrospectively analyzed. Demographic data, tumor characteristics, metastasis, and recurrence status were recorded. Data were analyzed using SPSS 25.0 software. Kaplan-Meier and Cox regression analysis were used for survival analysis. Results: The mean age was 54.43 years, with higher mortality in patients over 60 years old (p: 0.02). No significant difference in survival and recurrence was found between genders (p: 0.456). The most common symptom was abdominal pain. Patients with carcinoid syndrome had worse survival (p < 0.001). Midgut-origin cases had better survival (p: 0.014). Tumor diameter >3 cm, neuroendocrine carcinoma (NEC), lymphovascular invasion, regional lymph node involvement, and high mitotic counts were associated with higher mortality and recurrence rates (p < 0.01). Better survival was observed in cases with chromogranin positivity (p: 0.030), and cases with Ki67 index <20% had better survival and lower recurrence rates (p < 0.001). Distant organ metastasis, most commonly in the liver, was associated with survival (p < 0.001). Conclusion: In our study, age, tumor size, metastasis, and Ki-67 index were identified as significant prognostic factors and were evaluated in accordance with the literature. Keywords: neuroendocrine tumor, survival, recurrence, prognosis