The Lymph node ratio optimizes staging in patients with small intestinal neuroendocrine tumors

Background: The effectiveness of current Tumor, Lymph node, Metastases (TNM) staging system in small intestinal neuroendocrine tumors (SiNETs) is unsatisfactory. Current N classification only distinguishes between node-negative and node-positive status. We aim to refine the N classification for updated TNM stage. Methods: Patients with non-metastatic SiNETs between 1988 and 2012 were enrolled in the Surveillance, Epidemiology, and End Results (SEER) database. Using the X-tile program, we calculated an optimal cut-off value for lymph node ratio (LNR) and proposed a novel Nr category. Survival outcomes were estimated using the Kaplan –Meier method and Cox regression model. Adjusted hazard ratio and cluster analysis were performed to differentiate TNrM stages. Results: Patients with existing TNM stage I and II had equivalent survival prognosis (P=0.214). Current N classification was not a significant predictor of patient surviv al (P=0.372). Multivariate analyses identified the revised Nr classification, based on LNR of 0.6 optimal cut-off value, as an independent prognostic factor (P=0.020). By incorporating the Nr classification, a revised TNrM which categorized patients into three new stage was proposed: stage I (T1-2Nr 0-1), stage II (T3Nr0-1) and stage III (TxNr2 or T4Nrx). TNrM stage had better stratification according to the survival outcome (primary cohort: stage I: reference, II: HR 3.852 95％CI 1.731-8.575; III HR 7.169 95％CI 3.220-15.963, P
Source: Neuroendocrinology - Category: Endocrinology Source Type: research