Genomic profiling in GIST: Implications in clinical outcome and future challenges.

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.

Psychological Distress, Fatigue and Quality of Life in Patients with Gastrointestinal Stromal Tumors.

Background: Gastrointestinal stromal tumors (GIST) represent 1% of all gastrointestinal tumors and are included in the list of rare diseases. Objective: 1) To evaluate levels of psychological distress, fatigue, and quality of life. 2) To identify the variables that most influence distress among Mexican patients with GIST. Design: A cross-sectional study was conducted with a consecutive sample of 100 patients with GIST, who completed the following questionnaires online: Hospital Anxiety and Depression Scale (HADS) as a measure of distress, Multidimensional Fatigue Inventory (MFI), and Quality of Life Questionnaire (QLQ C30). Results: Distress was present in 31% of patients. No association was found between distress and sociodemographic/clinical variables. The patients with distress demonstrated higher scores in all fatigue dimensions and, regarding quality of life, had more symptoms and were lower functioning. Distress was positively associated with all fatigue dimensions and with QLQ C30 symptoms. Negative associations were found between distress and QLQ C30 functioning dimensions. The predictors of psychological distress were general fatigue, reduced motivation, and emotional functioning. Conclusion: The percentage of patients with distress was akin to the levels found in patients with the most common types of cancer. Fatigue in patients with GIST should be evaluated and managed to improve distress levels.