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).
Twenty consecutive patients who underwent endoscopic treatment for SNADETs of less than 20 mm between January 2017 and December 2017 were enrolled. Targeted genomic sequencing was performed through NGS using a 160 cancer-related gene panel. We examined the alteration/mutation frequencies in SNADETs.
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 tumor was detected. We obtained NGS data for 16 samples. 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.
We detected APC alterations in most small SNADETs resected via endoscopic treatment, from LGD to carcinoma samples. Even in SNADETs classified as small LGD, KRAS and BRAF alterations were present in a few samples.