Predictive factors affecting lymph node metastasis in patients of resectable pancreatic neuroendocrine neoplasms：a single-center retrospective study

BACKGROUND Pancreatic neuroendocrine neoplasms (pNENs) present great heterogeneity in biological behavior, histological characteristics and clinical manifestations. Monocyte-to-lymphocyte ratio (MLR) is a non-invasive and easy to obtain indicator, which can reflect disease severity in multiple tumors. Lymph node metastasis (LNM) has a great impact on patient's surgical approach and prognosis. Predicting LNM before surgery has a guiding significance for clinical treatment. AIM We aimed to evaluate the predictive factors including MLR associated with LNM of patients with resectable pNEN in our center. METHODS A total of 64 patients who underwent pNEN resection and lymph nodes dissection in our hospital from July 2014 until June 2023 were included in this study. Univariate and multivariate analyses were applied to identify predictive factors for LNM by analyzing clinical data, inflammatory markers, and pathological features. RESULTS Among the 64 patients, 15 (23.4%) patients were node positive. Univariate analysis showed that vascular invasion, peripheral nerve invasion, bilirubin level, tumor grade, tumor size and MLR (p<0.05 for all) were risk factor for LNM. Multivariate logistic analysis demonstrated that tumor size was the only independent risk factor for LNM in our research. Multivariate ROC analysis had better predictive performance than univariate analysis. CONCLUSION The preoperative MLR, vascular invasion, peripheral nerve invasion, bilirubin level, tumor grade and tumor size are potential predictors for LNM, especially during the initial diagnosis for resectable pNENs. Multivariate ROC analysis had better predictive performance than univariate analysis.