Gastrointestinal Stromal Tumors (GIST) are the most frequent mesenchymal neoplasia of the digestive tract. Genomic alterations in KIT, PDFGRA, SDH, and BRAF genes are essential in GIST oncogenesis. Therefore, the mutations in these genes have demonstrated clinical implications. Tumors with deletions in KIT-exon 11 or duplications in exon 9 are associated with a worse prognosis. In contrast, KIT-exon 11 substitutions and duplications are associated with a better clinical outcome. Moreover, mutations in Kit exon 9 and 11 are actionable, due to their response to imatinib, while mutations in PDGFRA respond to sunitinib and/or avapritinib. Although, molecular testing on tissue samples is effective; it is invasive, requires adequate amounts of tissue, and a long experimental process is needed for results. In contrast, liquid biopsy has been proposed as a simple and non-invasive method to test biomarkers in cancer. The most common molecule analyzed by liquid biopsy is circulating tumor DNA (ctDNA). GISTs ctDNA testing has been demonstrated to be effective in identifying known and novel KIT mutations that were not detected using traditional tissue DNA testing and have been useful in determining progression risk and response to TKI therapy. This allows the clinician to have an accurate picture of the genetic changes of the tumor over time. In this work, we aimed to discuss the implications of mutational testing in clinical outcomes, the methods to test ctDNA and the future challenges in the establishment of alternatives of personalized medicine.

胃肠道间质瘤（GIST）是消化道最常见的间叶性肿瘤。KIT、PDFGRA、SDH 和 BRAF 基因的基因组改变对于 GIST 肿瘤发生至关重要。因此，这些基因的突变已显示出临床意义。KIT-外显子 11 缺失或外显子 9 重复的肿瘤与较差的预后相关。相比之下，KIT-外显子 11 替换和重复与更好的临床结果相关。此外，Kit 外显子 9 和 11 中的突变是可操作的，因为它们对伊马替尼有反应，而 PDGFRA 中的突变对舒尼替尼和/或阿瓦普替尼有反应。尽管对组织样本进行分子检测是有效的；它是侵入性的，需要足够量的组织，并且需要很长的实验过程才能得到结果。相比之下，液体活检被提议作为一种简单且非侵入性的方法来测试癌症中的生物标志物。液体活检分析的最常见分子是循环肿瘤 DNA (ctDNA)。GIST ctDNA 检测已被证明可以有效识别传统组织 DNA 检测无法检测到的已知和新型 KIT 突变，并且有助于确定进展风险和对 TKI 治疗的反应。这使得临床医生能够准确了解肿瘤随时间的遗传变化。在这项工作中，我们旨在讨论突变测试对临床结果的影响、测试 ctDNA 的方法以及建立个性化医疗替代方案的未来挑战。