Ciara Kelly, MBBCh, BAO, interim clinical director of the Sarcoma Oncology Service at Memorial Sloan Kettering Cancer Center (MSKCC), discusses the management of patients with gastrointestinal stromal tumors (GISTs), emphasizing the importance of testing for genetic abnormalities and explaining how she performs this testing in her own clinical practice.
When treating patients with GIST, it is critical to determine the optimal timing and approach for genetic testing, Kelly begins. Ideally, tumor sequencing should be performed at baseline, during recurrence, and serially in cases of metastatic disease involving TKI therapies, Kelly says. She says that in her practice, she prioritizes sequencing GIST tumors at baseline to identify the specific molecular subtype of the tumor, which guides the initial treatment strategy. In addition, she noted that she performs sequencing again at recurrence to reevaluate the genetic profile of the tumor. Additional sequencing may also be considered at certain points during the course of treatment, Kelly reports, particularly when the results may inform decisions regarding treatment adjustments.
The standard approach to molecular characterization of GIST involves sequencing tumor tissue, a technique that has evolved significantly over the years due to advances in sequencing technology, she continues. At MSKCC, oncologists use a next-generation sequencing platform to achieve precise genetic characterization of GIST tumors, she says. Another emerging sequencing method is circulating tumor DNA (ctDNA) analysis, which detects gene mutations by examining the extracellular DNA released by tumor cells, Kelly explains. This technology has gained traction as an FDA-approved companion diagnostic in several cancers and is increasingly being used in GIST cases as well, she notes.
In addition, ctDNA is increasingly being used in clinical trials for GIST, providing valuable insights into its efficacy and usefulness in this disease, Kelly says. The integration of ctDNA testing into these trials has expanded the understanding of its role in the treatment of GIST, which may lead to more refined and personalized treatment strategies for patients in the future, Kelly concludes.
