Opposite treatment approach in two institutes identifies primary tumor resection to be associated with improved disease specific mortality in patients with stage IV small intestinal neuroendocrine tumors (SI-NET) vs watch-and-wait strategy

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Introduction: SI-NET often present with metastatic disease. There is an ongoing debate whether or not to perform primary tumor resection (PTR) in stage IV SI-NET.

Aim(s): The aim of this study was to compare a treatment strategy with upfront surgical resection vs a surveillance strategy of watch and wait.

Materials and methods: This was a retrospective cohort study of patients (pts) with stage IV SI-NET at diagnosis, between 2000-2018, from two tertiary referral centres (Netherlands Cancer Institute [NKI] and Aintree University Hospital [AUH]) who had adopted different treatment approaches consisting of surgical resection of the primary tumor vs watch and wait respectively. Pts without symptoms related to the primary tumor (PT) were included. Multivariable intention-to-treat (ITT), per-protocol (PP), and instrumental variable (IV) analysis using ‘institute’ as an IV were performed to assess the influence of PTR on disease specific mortality (DSM).

Conference:

Presenting Author: Levy S

Authors: Levy S, Arthur J, Banks M, Kok N, Fenwick S,

Keywords: SI-NET, surgical approach, stage 4, instrumental variable,