Impact of margin status on outcomes after endoscopic resection of well-differentiated duodenal neuroendocrine tumors.

ABSTRACT

BACKGROUND AND AIMS: Duodenal neuroendocrine tumors (DNETs) are known to have low metastatic potential and follow an indolent course. Although DNETs <1 cm in size are amenable to endoscopic resection, little is known about the long-term outcomes and recurrence rates of this approach. METHODS: Sixty-three patients with DNETs from 3 centers were retrospectively studied from 2003 to 2018. We analyzed their resection modality (EMR, snare polypectomy, or forceps polypectomy), margin status, risk factors for recurrence, recurrence rate, and endoscopic surveillance patterns. RESULTS: Of the 63 patients who underwent endoscopic resection, 13 (20.6%) had recurrence. The presence of R1 margins was found to be a statistically significant risk factor for recurrence (P = .048). Mean surveillance time for all DNETs was 2.8 ± 2.6 years. Ninety-two percent of recurrences were detected within 3 years of resection. CONCLUSIONS: Our data suggest that the main predictor of recurrence in low-grade DNETs <1.0 cm is the presence of positive tumor margins at the initial endoscopic resection. More frequent, earlier surveillance after resection than that currently recommended by European Neuroendocrine Tumor Society guidelines may be warranted to promptly capture DNET recurrences. Additionally, no recurrences occurred in our cohort after 4 years of surveillance.