Merck Manual

Please confirm that you are a health care professional

honeypot link

Gastrointestinal Stromal Tumors (GISTs)

By

Minhhuyen Nguyen

, MD, Fox Chase Cancer Center, Temple University

Last full review/revision Mar 2021| Content last modified Mar 2021
Click here for Patient Education

Gastrointestinal stromal tumors are tumors of the gastrointestinal tract derived from mesenchymal precursor cells in the gut wall.

Gastrointestinal stromal tumors (GISTs) result from mutations of a growth factor receptor gene, C-KIT. Some are caused by previous radiation therapy to the abdomen for other tumors.

Tumors are slow growing, and malignant potential varies from minimal to significant. Most (60 to 70%) occur in the stomach, 20 to 25% in the small bowel, and a small number in the esophagus, colon, and rectum. Average age at presentation is 50 to 60.

Diagnosis of GISTs is usually by endoscopy, with biopsy and endoscopic ultrasonography for staging.

Treatment of GISTs is surgical removal. The tyrosine kinase inhibitor imatinib can be used when tumors are positive for the KIT protein CD117; it is effective for patients with unresectable and/or metastatic malignant GISTs and also as adjuvant treatment following resection in adults (1 Treatment reference Gastrointestinal stromal tumors are tumors of the gastrointestinal tract derived from mesenchymal precursor cells in the gut wall. Gastrointestinal stromal tumors (GISTs) result from mutations... read more ). For imatinib-refractory tumors, sunitinib and regorafenib can be used.

Avapritinib, another tyrosine kinase inhibitor, should be used as first-line therapy for patients with a platelet-derived growth factor receptor alpha (PDGFRA) exon 18 mutation, including PDGFRA D842V mutations.

Treatment reference

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read
Test your knowledge
Hemorrhoids
A 32-year-old woman who is at 30 weeks’ gestation comes to the office because she has had pain on defecation during the past week. She says she also has had pain when attempting to cleanse the anal region as well as pain when sitting. Based on these findings, which of the following types of hemorrhoid is most likely to be noted on further evaluation of this patient?  
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
 

Also of Interest

 
TOP