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Health condition · Clinically reviewed

Gastrointestinal stromal tumours, rare sarcomas of the gut, treated with surgery and targeted therapy.

GIST is uncommon but well understood. Molecular profiling, careful surgery and a ladder of tyrosine kinase inhibitors give most people a clear plan.

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A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against ESMO, NCCN and specialist sarcoma-society sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK practice including molecular profiling, ripretinib and avapritinib for D842V PDGFRA disease.

Key facts

GIST at a glance.

The essentials, in plain English. What it is, where it starts, and how it is treated in the UK today.

  • What it is

    A rare mesenchymal tumour of the gastrointestinal tract arising from the interstitial cells of Cajal, the pacemaker cells of the gut wall.

  • How common

    Around 600 new UK cases each year with a peak age of 55 to 75 and roughly equal incidence in men and women.

  • Where it starts

    Stomach in about 60 per cent, small bowel in around 30 per cent, colon and rectum in about 5 per cent, oesophagus rarely.

  • Molecular hallmark

    KIT (CD117) mutations in about 80 per cent, PDGFRA in around 10 per cent, and SDH-deficient tumours in about 10 per cent.

  • How it presents

    Gastrointestinal bleeding and anaemia, abdominal pain, a palpable mass, obstruction, or incidentally at endoscopy or imaging.

  • Cornerstone of care

    Complete surgical resection for localised disease, with imatinib and later-line tyrosine kinase inhibitors for advanced or metastatic tumours.

Why this guide matters

A rare cancer, a clear pathway.

GIST behaves differently to adenocarcinomas of the gut. The three points below shape the whole treatment plan.

  • Molecular profile drives treatment

    KIT, PDGFRA and SDH status decide whether imatinib, avapritinib or a specialist SDH-deficient pathway is used.

  • Surgery cures many localised tumours

    Complete resection with negative margins and no rupture, at a specialist sarcoma centre, is the single biggest factor.

  • Advanced disease is a long-term plan

    A ladder of imatinib, sunitinib, regorafenib and ripretinib turns metastatic GIST into a chronic condition for many people.

How the diagnosis is made

From first symptom to a specialist plan.

The steps a UK GP, gastroenterologist or sarcoma team will normally follow, so you know what to expect and why.

  1. 01

    Assessing

    History and risk factors

    Bleeding, dyspepsia, anaemia, family history and any syndromic features such as Carney triad or NF1.

  2. 02

    Assessing

    CT abdomen and pelvis

    Contrast-enhanced staging CT localises the mass, assesses size and looks for peritoneal or liver disease.

  3. 03

    Assessing

    Endoscopy and EUS biopsy

    Upper GI endoscopy with endoscopic ultrasound guided biopsy characterises subepithelial lesions safely (see /treatments/endoscopic-ultrasound/).

  4. 04

    Confirming

    Specialist histology and IHC

    Reviewed by specialist sarcoma pathology with CD117, DOG1, CD34 and SMA to confirm the diagnosis.

  5. 05

    Confirming

    Molecular profiling

    KIT, PDGFRA, SDH and BRAF testing guides treatment choice and dose. Wild-type and SDH-deficient tumours need specialist genetics.

  6. 06

    Planning

    Risk stratification

    Size, mitotic count, location and any rupture are combined using Miettinen or AFIP criteria to estimate relapse risk.

  7. 07

    Planning

    Specialist sarcoma MDT

    Managed at commissioned UK sarcoma centres such as the Royal Marsden or the Christie, with input from upper GI surgery and medical oncology.

Typical timeline: from first scan to a specialist sarcoma MDT plan in a few weeks.

Symptoms

What GIST tends to look like.

Many GISTs are silent for years. When symptoms appear they are often bleeding, pain or a mass, and the features below deserve prompt attention.

  • Gastrointestinal bleeding

    Melaena, haematemesis or occult blood loss with iron deficiency anaemia (see /conditions/gastrointestinal-bleeding/).

  • Abdominal pain

    Vague upper abdominal discomfort, fullness or a dragging ache that has crept up over weeks.

  • Palpable mass

    A firm, sometimes tender mass felt in the upper abdomen, more often with larger gastric or small bowel tumours.

  • Early satiety and nausea

    Feeling full quickly, reflux or nausea when a stomach lesion presses on the lumen.

  • Obstruction

    Small bowel or gastric outlet obstruction with vomiting and distension in larger tumours.

  • Incidental finding

    Around 30 per cent are picked up incidentally at endoscopy, CT or laparotomy for another reason.

  • Constitutional symptoms

    Weight loss, fatigue and reduced appetite in more advanced or metastatic disease.

  • Red flag: tumour rupture

    Sudden severe abdominal pain with peritonitis suggests rupture and peritoneal seeding, needing urgent surgical review.

Treatment

How GIST is treated in the UK.

Surgery for localised disease, adjuvant imatinib for high-risk tumours, and a ladder of targeted therapies for advanced or metastatic GIST.

  • Surgical resection

    The mainstay for localised disease. Complete resection with negative margins and no rupture, often laparoscopic (see /treatments/gist-resection/).

  • Neoadjuvant imatinib

    Shrinks large, borderline resectable or rectal tumours before surgery, coordinated by specialist medical oncology.

  • Adjuvant imatinib

    Three years of imatinib after surgery for high-risk tumours improves recurrence-free and overall survival (SSGXVIII).

  • First-line imatinib

    Glivec, 400 mg daily, for advanced or metastatic disease. KIT exon 9 tumours are dosed at 800 mg daily.

  • Second-line sunitinib

    Sutent for progression on or intolerance of imatinib, with attention to blood pressure, thyroid and hand-foot syndrome.

  • Third-line regorafenib

    Stivarga after imatinib and sunitinib, with close monitoring of liver function and skin toxicity.

  • Ripretinib and avapritinib

    Ripretinib (Qinlock) is a switch-control inhibitor used fourth-line. Avapritinib (Ayvakit) is used for PDGFRA D842V disease.

  • SDH-deficient pathway

    Imatinib is often ineffective. Care is specialist commissioned with SDH-B, C and D genetic screening and Carney syndrome review.

What this guide is based on

The sources behind every claim on this page.

International sarcoma guidance and UK-specific commissioning standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your sarcoma MDT knows your imaging, histology and molecular profile and can tell you which parts apply to you. If in doubt, ask.

  • ESMO Clinical Practice Guidelines. Gastrointestinal stromal tumours: diagnosis, treatment and follow-up.

  • NCCN Clinical Practice Guidelines in Oncology. Gastrointestinal stromal tumours (GIST).

  • NICE technology appraisals on imatinib, sunitinib, regorafenib, ripretinib and avapritinib for GIST.

  • Sarcoma UK. Patient information and support resources for people living with GIST.

Red flags

When GIST needs urgent attention.

Most GISTs are managed on a planned pathway. These are the situations that need faster escalation.

  • Tumour rupture and peritonitis

    Sudden severe abdominal pain, peritonism and shock. Rupture markedly increases the risk of peritoneal recurrence and needs emergency surgery.

  • Major GI bleeding

    Haematemesis, melaena or haemodynamic instability need urgent hospital admission for resuscitation and endoscopy.

  • Obstruction

    Persistent vomiting, distension and absent bowel motions warrant urgent imaging and surgical assessment.

  • Rapid growth on imaging

    A subepithelial lesion increasing in size on surveillance should prompt urgent specialist sarcoma review.

  • Symptoms during TKI therapy

    New oedema, breathlessness, bleeding or severe rash on imatinib, sunitinib or regorafenib needs prompt oncology review.

  • Syndromic features

    Neurofibromatosis, paraganglioma or a family history of GIST suggests SDH-deficient or NF1-related disease and specialist genetics.

  • Paediatric or young adult GIST

    Almost always SDH-deficient with different biology. Refer to a specialist paediatric or young-adult sarcoma centre.

  • Recurrent disease after resection

    New liver or peritoneal deposits on surveillance imaging need urgent MDT discussion and molecular re-evaluation.

  • Uncontrolled pain or weight loss

    Progressive pain, cachexia and functional decline deserve rapid oncology and palliative-care input.

Living with it

A specialist condition, a long-term partnership.

Four things that make the biggest difference over the months and years after diagnosis: surveillance, treatment adherence, nutrition and support.

A quiet reminder

Consistency beats intensity, every time.

Steady tablets, steady scans and honest conversations with your team keep the plan working.

  1. 01 Follow-up

    Stick with surveillance

    Regular CT scans, usually every three to six months for higher-risk tumours, catch recurrence when it is still treatable.

  2. 02 Adherence

    Take TKIs consistently

    Imatinib and later-line agents work best when taken every day. Tell your team about side effects rather than stopping on your own.

  3. 03 Nutrition

    Eat little and often

    After stomach or bowel surgery, smaller frequent meals and a dietitian review help you maintain weight and energy.

  4. 04 Support

    Use specialist charities

    Sarcoma UK and GIST patient groups offer peer support, up-to-date information and help navigating specialist commissioned care.

Frequently asked

Everything we get asked about GIST.

Quick answers on diagnosis, surgery, imatinib, later-line drugs and SDH-deficient disease.

  • What is a gastrointestinal stromal tumour?

    A gastrointestinal stromal tumour, or GIST, is a rare mesenchymal tumour of the digestive tract. It arises from the interstitial cells of Cajal, the pacemaker cells that coordinate gut movement, and most commonly develops in the stomach or small bowel.

  • How is GIST diagnosed?

    Diagnosis usually starts with a CT scan and upper GI endoscopy, then an endoscopic ultrasound guided biopsy. Specialist sarcoma pathology confirms the diagnosis using CD117, DOG1, CD34 and SMA, and molecular testing for KIT, PDGFRA, SDH and BRAF guides treatment.

  • Is GIST cancer?

    GISTs are considered malignant tumours with a variable risk of spread. Risk is estimated using size, mitotic count, location and whether the tumour ruptured. Small, low mitotic gastric GISTs may behave almost like benign lesions, while larger small bowel tumours have a much higher risk of recurrence.

  • What is the main treatment for GIST?

    For localised disease the mainstay is complete surgical removal with clear margins and no tumour rupture. High-risk tumours receive three years of adjuvant imatinib. Advanced or metastatic disease is treated with a sequence of tyrosine kinase inhibitors, starting with imatinib.

  • What if imatinib stops working?

    Second-line treatment is sunitinib, third-line is regorafenib and fourth-line is ripretinib. Avapritinib is used for tumours with the PDGFRA D842V mutation, which is resistant to imatinib. Choice is guided by molecular profile and previous tolerance.

  • Are paediatric and SDH-deficient GISTs different?

    Yes. SDH-deficient GISTs, which include most paediatric cases and syndromes such as Carney triad and Carney-Stratakis, arise through a different mechanism. Imatinib is often ineffective, and care needs a specialist commissioned centre with genetic screening for SDH-B, C and D.

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