A 'watch and wait' strategy involving regular endoscopic surveillance is safe for many patients with small, sporadic, grade 1, non-ampullary, non-functioning duodenal neuroendocrine tumours.

Exarchou, Klaire; Moore, Andrew R; Smart, Howard L; Duckworth, Carrie A; Howes, Nathan; Pritchard, D Mark

Introduction Duodenal neuroendocrine tumours (d-NETs) are rare, but are increasing in incidence. Current ENETS guidelines advocate resection of all localised d-NETs. However, 'watch and wait' may be appropriate for some localised, small, grade 1, non-functioning, non-ampullary d-NETs. We evaluated whether patients with such d-NETs who chose 'watch and wait' involving regular endoscopic surveillance had equivalent disease-related outcomes to patients undergoing endoscopic or surgical resection. Methods Retrospective review of patients with histologically confirmed d-NETs at Liverpool ENETS Centre of Excellence 2007-2020. Results Sixty-nine patients were diagnosed with d-NET of which fifty were sporadic, non-functioning, non-ampullary tumours. Patient treatment groups were similar in terms of age, gender, tumour location and grade, but unsurprisingly, larger tumours (median diameter 17mm (p<0.0001)) were found in the surgically treated group. Five patients underwent surgical resection with no evidence of tumour recurrence or disease-related death. Twelve patients underwent endoscopic resection, with one local recurrence detected during follow-up. Thirty patients (28 with d-NETs ≤10mm) underwent 'watch and wait' with resection only if tumours increased in size. The d-NETs in 28/30 patients remained stable or decreased in size over a median 27 months (IQR:15-48, R:3-98). In seven patients the d-NET was completely removed by avulsion during diagnostic biopsy and was not seen at subsequent endoscopies. Only two patients showed increased d-NET size during surveillance, of whom only one was fit for endoscopic resection. No NET-related deaths were documented during follow up. Conclusions All of the localised, ≤10mm, grade 1, non-functioning, non-ampullary d-NETs in this cohort behaved indolently with very low risks of progression and no tumour-related deaths. 'Watch and wait' therefore appears to be a safe alternative management strategy for selected d-NETs.