Endoscopic treatment selection for superficial duodenal tumors: pay attention to small lesions

We read with great interest the study by Kato et al. [1]. The authors reported their experience of endoscopic resection in treating duodenal tumors in several Japanese endoscopy centers. We wish to discuss several details.

First, the authors reported that the en bloc resection rate of underwater endoscopic mucosal resection (UEMR) was significantly lower than that of EMR. A main distinguishing feature of UEMR from EMR is that the buoyancy effect of water immersion allows the inclusion of a larger quantity of mucosa within the snare, which makes the whole resection of the lesion in one piece more likely. Recently, other studies from Japan have suggested that UEMR achieves a higher en bloc resection rate compared with EMR for duodenal tumors [2] [3]. In addition, these studies also suggested that UEMR had a higher R0 resection rate for duodenal tumors ≤ 20 mm. The heterogeneity between current studies suggests that the appropriate endoscopic resection method for small duodenal tumors still needs to be explored.

Second, the authors found that endoscopic submucosal dissection (ESD) had a lower local recurrence rate compared with non-ESD resection methods, especially for large duodenal tumors ( ≥ 30 mm). In another recent study, however, incomplete resection was more likely to occur in larger lesions and local recurrence was more likely to be found at follow-up [4]. The key issue may lie in whether the local recurrence rate of ESD and non-ESD methods is similar for small lesions, which could further reflect the long-term outcomes of non-ESD resection methods. The stratification analysis of local recurrence between the groups for small lesions (similar to the stratification of resection rates) may further support the selection of non-ESD resection methods as suggested by the authors.

In conclusion, we believe there are still unanswered questions about the selection of resection methods for small duodenal tumors.

Publication History

Article published online:
21 April 2022

• References

• 1 Kato M, Takeuchi Y, Hoteya S. et al. Outcomes of endoscopic resection for superficial duodenal tumors: 10 years’ experience in 18 Japanese high-volume centers. Endoscopy 2021; DOI: 10.1055/a-1640-3236.
• 2 Furukawa M, Mitoro A, Ozutumi T. et al. Efficacy of underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumor. Clin Endosc 2021; 54: 371-378
• 3 Okimoto K, Maruoka D, Matsumura T. et al. The utility of underwater endoscopic mucosal resection for nonpolypoid superficial nonampullary duodenal epithelial tumors ≤20 mm. Gastrointest Endosc 2021; DOI: 10.1016/j.gie.2021.07.011.
• 4 Hirasawa K, Ozeki Y, Sawada A. et al. Appropriate endoscopic treatment selection and surveillance for superficial non-ampullary duodenal epithelial tumors. Scand J Gastroenterol 2021; 56: 342-350