Peritoneal Carcinomatosis in Well-Differentiated Small-Intestinal Neuroendocrine Tumors with Mesenteric Tumor Deposits.

Abstract

Well-differentiated small-intestinal neuroendocrine tumors (SI-NETs) tend to be biologically indolent. Despite this tendency, they have a predilection for metastasis. Peritoneal involvement is quite common as is unfortunately peritoneal carcinomatosis (PC). PC is a dreaded metastatic complication due to the significant morbidity it creates for patients as well as well as increasing their mortality risk. The risk factors for PC development in SI-NETs remain understudied; however, one such factor may be the presence of mesenteric tumor deposits (MTDs). We performed a retrospective analysis on 208 well-differentiated SI-NET patient samples, the majority with mesenteric masses, from the pathology archives of Vanderbilt University Medical Center. We sought to explore whether MTD presence was associated with PC, what other patient determinants were associated with PC and prognostic implication of these determinants. Patients with MTDs had an OR of 3.9 (CI 1.6, 10.9) for PC compared to patients without MTDs in the analysis. Patients who developed PC fared more poorly than those who did not (p=0.044). Our analysis, to the best of our knowledge, is the first to demonstrate an association between MTD presence and PC in this patient subgroup. We believe this finding warrants prospective evaluation given the possible therapeutic implications of being able to stratify SI-NET patients by their risk for developing PC based upon MTD presence.