Relationship between gene mutations and clinicopathological features in nonampullary duodenal epithelial tumors

Abstract

Background: Molecular features of nonampullary duodenal epithelial tumors (NADETs) remain unclear.

Aim: The aim of this study is to determine the association between the genetic features and clinicopathological findings of NADETs.

Methods: In total, 75 NADETs were enrolled in this study, and was performed targeted DNA sequencing of the GNAS, KRAS, TP53, and APC genes. Histological grade was classified as category 3 or category 4/5 according to the Vienna classification, and the immunophenotype was categorized as the gastric phenotype (G type), gastrointestinal phenotype (GI type), or the intestinal phenotype (I type).

Results: The prevalence of GNAS and KRAS mutations was significantly higher in the G type than in the GI/I type (GNAS, P = 0.027; KRAS, P = 0.005). In contrast, the frequency of TP53 mutations was significantly higher in the GI/I type than in the G type (P = 0.049). Notably, APC mutations, excluding c.4479 G>A which was synonymous mutation, were more frequently identified in category 4/5 tumors than in category 3 tumors (50% vs. 24.5%; P = 0.039).

Conclusion: G-type NADETs harbored frequent GNAS and KRAS mutations, whereas TP53 mutations are common in NADETs with intestinal features. APC mutations were significantly associated with high-grade neoplasia and invasive carcinoma.

Keywords: Duodenal tumor; Gene mutation.