Gastrointestinal Stromal Tumour
A gastrointestinal stromal tumour (GIST) is a rare soft-tissue tumour that arises in the wall of the digestive tract, most commonly in the stomach or small intestine. GISTs develop from specialised cells called interstitial cells of Cajal, which help regulate gut movement. They are distinct from other digestive cancers and require a specific diagnostic and treatment approach.
Key points
- The tumour originates from the cells of Cajal, a specialised cell type that normally paces the gut’s muscular contractions.
- A KIT or PDGFRA gene mutation is present in most cases, explaining the strong response to targeted therapy over conventional chemotherapy.
- Tyrosine kinase inhibitor therapy, most established with imatinib, is used both to reduce recurrence risk after surgery and to treat advanced disease.
How GISTs are detected and managed
Smaller GISTs often produce no symptoms and are found incidentally during imaging or endoscopy. Larger tumours may cause abdominal discomfort, a palpable mass, bleeding, or anaemia. Diagnosis relies on imaging (CT or MRI) and biopsy with immunohistochemistry, typically looking for the KIT (CD117) protein marker.
The majority of GISTs carry mutations in the KIT or PDGFRA gene. This molecular feature makes them highly responsive to targeted therapy rather than conventional chemotherapy. Imatinib, a tyrosine kinase inhibitor, is the established first-line systemic treatment and is used both after surgery to reduce recurrence risk and for advanced or metastatic disease. It sits within the broader field of oncology support.
Surgery remains the primary treatment for localised, resectable GISTs. Ongoing monitoring with imaging is standard, as GISTs can recur years after initial treatment. Anyone with unexplained abdominal bleeding or a growing abdominal mass should seek prompt medical evaluation.