Predicting Survival of Small Intestine Neuroendocrine Tumors: Experience From a Major Referral Center

Abstract

Objective Neuroendocrine tumors (NETs) comprise 41.8% of small intestine malignancies. The NET nomogram is a 15-item prognostic tool that includes relevant factors for guiding management decisions. This is the first external validation of this tool among American patients at a tertiary treatment center. Methods Patients who underwent surgical intervention from 2005 to 2017 were screened by retrospective chart review. Nomogram scores were calculated following the methods outlined by Modlin et al (Neuroendocrinology. 2010;92:143–157). Validation assessed the association between nomogram scores and survival using Wilcoxon test and Cox regression. Results Among the 121 patients selected, the NET nomogram significantly predicted survival as a continuous variable (P < 0.01) and when dichotomized using 83 points to distinguish low-risk versus high-risk groups (P < 0.01). However, the nomogram was not universally applicable as even at our specialty center, variables such as chromogranin A and urinary 5-hydroxyindoleacetic acid are not routinely collected, whereas others, like tumor grade, do not reflect the most recently updated classifications. Conclusion The NET nomogram accurately identified patients at low and high risk of death. However, revision to update prognosticators could improve its usefulness for predicting survival of small intestine NETs.