Can Lymph Node Metastasis be Predicted in Gastroenteropancreatic Neuroendocrine Neoplasias?

Objective: To investigate the predictive factors influencing lymphatic metastasis in gastroenteropancreatic neuroendocrine neoplasm (GEP-NENs).

Study design: Observational study. Place and Duration of the Study: Department of General Surgery, Ankara City Hospital, Ankara, Turkiye, between the years 2019 and 2022.

Methodology: Patients who underwent surgery and were diagnosed with GEP-NEN based on final pathology between the study years were enrolled. Demographic information of the patients including age, gender, tumour location, and pathological characteristics (tumour size, grade, Ki-67 index, mitotic rate, total number of lymph nodes examined, pathological lymph nodes), inflammatory markers (White blood cell, lymphocyte, neutrophil, and monocyte counts, albumin levels, modified systemic inflammation score [mSIS], delta neutrophil index [DNI], neutrophil-lymphocyte ratio [NLR], and lymphocyte-monocyte ratio [LMR]) were retrieved from the patient database.

Results: One hundred and thirty-two patients were included. The median age was 51 (34-64) years, with 56.8% being male. GEP- NENs were most commonly found in the pancreas (43.2%) and appendix (22.7%). The median tumour size was 1.7 cm (0.7-3.5 cm), the mitotic rate was 1(1-2), and the Ki-67 Index was 2 (1-5). Grade I and II accounted for 91.6 % of cases. In multivariate analysis, independent predictive factors for pathological lymph node involvement were identified as small bowel tumour location (p = 0.002), tumour Grade III (p = 0.008), and tumour size ≥2 cm (p = 0.017).

Conclusion: This study identified tumour size, grade, and site of origin as independent risk factors for LN metastasis.

Key words: Neuroendocrine neoplasm, Lymph node metastasis, Gastrointestinal system.