Can underwater endoscopic mucosal resection be an alternative to conventional endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumors?

Objectives

Underwater endoscopic mucosal resection (UEMR) is a simpler procedure for superficial non-ampullary duodenal epithelial tumors (SNADET) than conventional endoscopic mucosal resection (cEMR). This study aimed to evaluate whether cEMR can be substituted by UEMR for SNADET in terms of effectiveness, safety, and learning curve.

Methods

A total of 157 consecutive patients with 203 SNADETs ≤20 mm in diameter, including 107 lesions resected by cEMR and 96 lesions resected by UEMR, between January 2019 and May 2023, were retrospectively recruited. The treatment outcomes were compared between the cEMR and UEMR groups. The risk factors for incomplete resection by UEMR were analyzed using univariate and multivariate analyses. Lesions in the UEMR group were divided chronologically into five periods; thereafter, the en bloc resection rate and procedure time were compared.

Results

No significant differences existed between the cEMR and UEMR groups in the mean procedure time (3.9 min vs. 3.6 min, p = 0.1380) or en bloc resection rate (91% vs. 94%, p = 0.4138). No perforation was observed in either group. Tumor size was an independent risk factor for incomplete resection using UEMR (p < 0.01). The history of biopsy was not associated with incomplete resection using UEMR. The en bloc resection rate of UEMR was 100% (20/20) in the first period and ranged from 90% to 100% over all periods.

Conclusion

UEMR is safe and effective for SNADET ≤20 mm, regardless of a history of biopsy, and is easy to learn. Thus, UEMR can serve as an alternative to cEMR.

Genomic profiling of intestinal/mixed-type superficial non-ampullary duodenal epithelial tumors

Background and Aim

The mechanism underlying carcinogenesis and the genomic features of superficial non‐ampullary duodenal epithelial tumors (SNADETs) have not been elucidated in detail. In this study, we examined the genomic features of incipient SNADETs, such as small lesions resected via endoscopic treatment, using next‐generation sequencing (NGS).

Methods

Twenty consecutive patients who underwent endoscopic treatment for SNADETs of less than 20 mm between January and December 2017 were enrolled. Targeted genomic sequencing was performed through NGS using a panel of 160 cancer‐related genes. Furthermore, the alteration/mutation frequencies in SNADETs were examined.

Results

The maximum size of the SNADETs examined in this study was 12 mm in diameter. Five SNADETs were classified as low‐grade dysplasia (LGD) tumors, while 14 SNADETs were classified as high‐grade dysplasia tumors. Only one carcinoma in situ was detected. NGS data for 16 samples were obtained. APC alterations were detected in 81% of samples (13/16). KRAS, BRAF, and TP53 alterations were detected in 25% (4/16), 18.8% (3/16), and 6.3% (1/16) of cases, respectively.

Conclusion

We detected APC alterations in most small SNADETs resected via endoscopic treatment, from LGD to carcinoma samples. Even in SNADETs classified as small LGD exhibited KRAS and BRAF alterations.