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 takeaways
- GIST is biologically different from common stomach or bowel cancers and is classified using tissue and molecular testing.
- Surgery is important for many localised tumours; targeted medicines are used in selected higher-risk, unresectable or metastatic disease.
- The tumour’s KIT or PDGFRA mutation can predict whether a targeted medicine is likely to work.
A targeted-therapy listing is not a treatment recommendation; pathology, mutation results, tumour site, stage and surgical options must be reviewed by a specialist team.
How is GIST identified?
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.
How do test results shape treatment?
Surgery may remove a localised, resectable tumour. Imatinib blocks particular signalling pathways and may be used after surgery in higher-risk disease or for advanced GIST, but some mutations are resistant. Follow-up imaging matters because recurrence can occur after initial treatment. Care sits within oncology support.
When to seek urgent care
Seek urgent care for vomiting blood, black or bloody stools, fainting, sudden severe abdominal pain, a rapidly enlarging painful abdomen or fever and marked illness during cancer treatment.