Gastrointestinal stromal tumors of the rectum

Gastrointestinal stromal tumors (GIST) are rare tumors that can arise in the whole gastrointestinal tract and belong to the group of soft tissue sarcomas. They represent less than 1% of all gastrointestinal tumors and 90% of GISTs are located in the stomach and small intestine. Only 5% are found in the rectum and are therefore a rarity. In localized stages surgical resection is carried out and depending on the size and risk constellation, neoadjuvant or adjuvant systemic therapy is recommended. A mutational analysis on the tumor tissue is of central importance for treatment planning. Imatinib at a dose of 400 mg per day is the gold standard for advanced stages of disease. In patients with an exon 9 mutation the recommended dose is 800 mg imatinib per day. In imatinib-refractory disease or intolerance to imatinib, sunitinib, regorafenib, and ripretinib are further treatment options.