Survival of patients managed in France for duodenal neuroendocrine tumors (D-NET): a 20-year multicenter cohort study from the GTE group: a cohort study

Introduction: Duodenal neuroendocrine tumours (D-NETs) have a low incidence; however, their diagnosis has been increasing. Features such as tumour location, size, type, histological grade, and stage were used to adapt the treatment to either endoscopic (ER) or surgical (SR) resections. There is no consensus regarding the definitive treatment. The authors' study aimed to describe the management of non-metastatic, well-differentiated D-NETs in France and its impact on patient survival. Methods: A registry-based multicenter study using prospectively collected data between 2000 and 2019, including all patients managed for non-metastatic G1 and G2 D-NETs, was conducted in the GTE group. Results: A total of 153 patients were included. Fifty-eight benefited from an ER, and 95 had an SR. No difference in recurrence-free survival (RFS) was observed regardless of treatment type. There was no significant difference between the two groups (ER vs. SR) in terms of location, size, grade, or lymphadenopathy, regardless of the type of incomplete resection performed or regarding the pre-therapeutic assessment of lymph node invasion in imaging. The surgery allowed for significantly more complete resection (patients with R1 resection in the SR group: 9 vs. 14 in the ER group, P<0.001). Among the 51 patients with positive lymph node dissection after SR, tumour size was less than or equal to 1 cm in 25 cases. Surgical complications were more numerous (P=0.001). In the sub-group analysis of G1-G2 D-NETs between 11 and 19 mm, there was no significant difference in grade (P=0.977) and location (P=0.617) between the two groups (ER vs. SR). No significant difference was found in both morphological and functional imaging, focusing on the pre-therapeutic assessment of lymph node invasion (P=0.387). Conclusion: Regardless of the resection type (ER or SR) of G1-G2 non-metastatic D-NETs, as well as the type of management of incomplete resection, which was greater in the ER group, long-term survival results were similar between ER and SR. Organ preservation seems to be the best choice owing to the slow evolution of these tumours.