Introduction: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. It has distinct molecular features and primarily affects the KIT and PDGFRA genes. Objective: We wanted to assess the molecular profile of 68 GIST patients who were sequenced consecutively between 2014 and 2019 at our institute of pathology. Methods: Our cohort comprised 60 primary and 8 metastatic GIST patients; 43 and 57% of the cases, respectively, were analyzed by Sanger sequencing or next-generation sequencing (NGS). Results: Of the 60 primary GIST patients, 47 (78%) showed a KIT mutation; 2 cases showed a double KIT mutation, and 1 of these was a therapy-naive GIST. Nine (15%) patients harbored a PDGFRA mutation, 2 (3%) had a BRAF mutation, 1 (2%) had a PIK3CA mutation, and 1 (2%) did not show any mutation. One BRAF and the PIK3CA mutation have not been described in GIST before. All metastatic GIST harbored exclusively KIT mutations. Conclusion: A retrospective analysis of GIST sequenced at our institute revealed incidences of KIT and PDGFRA mutations comparable to those in other cohorts from Europe. Interestingly, we found 2 previously undescribed mutations in the BRAF and PIK3CA genes as well as 1 treatment-naive case with a double KIT mutation in exon 11.

中文翻译：

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来自一家瑞士机构的 68 名患者胃肠道间质瘤的分子特征

简介：胃肠道间质瘤（GIST）是胃肠道最常见的间叶性肿瘤。它具有独特的分子特征，主要影响 KIT 和 PDGFRA 基因。目的：我们想评估 2014 年至 2019 年在我们病理研究所连续测序的 68 名 GIST 患者的分子谱。方法：我们的队列包括 60 名原发性和 8 名转移性 GIST 患者；分别有 43% 和 57% 的病例通过 Sanger 测序或新一代测序 (NGS) 进行分析。结果：在 60 名原发性 GIST 患者中，47 名 (78%) 显示出 KIT 突变；2 例显示双 KIT 突变，其中 1 例是未经治疗的 GIST。9 名 (15%) 患者有 PDGFRA 突变，2 名 (3%) 有 BRAF 突变，1 名 (2%) 有 PIK3CA 突变，1 名 (2%) 没有显示任何突变。一种 BRAF 和 PIK3CA 突变以前未在 GIST 中描述过。所有转移性 GIST 仅包含 KIT 突变。结论：对我们研究所测序的 GIST 的回顾性分析揭示了 KIT 和 PDGFRA 突变的发生率与来自欧洲其他队列的发生率相当。有趣的是，我们在 BRAF 和 PIK3CA 基因中发现了 2 个以前未描述的突变，以及 1 个在外显子 11 中具有双 KIT 突变的未治疗病例。