Association between CT imaging features and KIT mutations in small intestinal gastrointestinal stromal tumors

Yi-Qiong Yin,Yue Wen,Chun-Juan Liu,Yuan Yin,Bo Zhang

doi:10.1038/s41598-019-43659-9

Abstract

Small intestinal gastrointestinal stromal tumors (GISTs) have different clinical outcomes when KIT mutations are in exons 11 or 9, which are also the most common sites of neoplastic KIT mutations. The purpose of this study is to evaluate the CT imaging features in those two groups. A total of 35 patients were enrolled, and both quantitative and qualitative CT imaging features were compared between patient groups with KIT exon 9 mutations (KIT–9) and exon 11 mutations (KIT–11). The KIT–9 group was statistically associated with a tumor size larger than 10 cm and a higher enhancement ratio when compared with those of the KIT–11 group (both P < 0.05). For the enhancement ratio, the receiver operating characteristic curve indicated a cut-off value of 1.60 to differentiate KIT–9 from KIT–11 tumors. Additionally, tumor necrosis was more commonly seen in the KIT-9 group. In multivariate analysis, tumor size (β = 0.206; P = 0.022) and KIT–9 (β = 0.389; P = 0.006) were independent factors associated with tumor necrosis. Taken together, KIT–9 mutant tumors tended to have CT imaging features indicative of more aggressive neoplasms. These findings may be helpful in identifying more aggressive small intestinal GISTs and optimizing treatment.

Highlights

Gastrointestinal stromal tumors (GISTs) are the main mesenchymal tumors of the gastrointestinal tract, with an annual incidence of 10–15 cases per million[1,2]
Data from previous research show that KIT exon 9 mutations are more frequent in small intestinal GISTs5,6
Ki-67 expression was higher in the KIT exon 9 (KIT–9) group than in the KIT–11 group (9.30 ± 7.01 vs. 7.30 ± 3.88; P < 0.05), whereas no differences were found in CD117, Dog-1, CD34, S-100, and SMA expression

Summary

Introduction

Gastrointestinal stromal tumors (GISTs) are the main mesenchymal tumors of the gastrointestinal tract, with an annual incidence of 10–15 cases per million[1,2]. More than 80% of GISTs express KIT-activating mutations, most frequently in exon 11. This is the genetic locus that responds to tyrosine kinase inhibitor (TKI) therapy. Data from previous research show that KIT exon 9 mutations are more frequent in small intestinal GISTs5,6. To the best of our knowledge, several studies have described the CT imaging features of small intestine GISTs7,8, whether there are differences between GISTs in patients with KIT exon 9 (KIT–9) versus exon 11 (KIT–11) mutations remains unclear. In this study, we sought to identify CT-visible differences between these groups under the hypothesis that differences in KIT activity related to the mutation site would create such features. CT imaging could be a useful tool for identifying more aggressive tumors and optimizing clinical treatment

Objectives

Methods

Results

Conclusion