Gastrointestinal stromal tumor medical therapy

Medical Therapy
Most small GISTs (<5 and especially <2 cm) with a low rate of mitosis (<5 dividing cells per 50 high-power fields) are benign and,after surgery, do not require adjuvant therapy.

Larger GISTs (>5 cm), and especially when the cell division rate is high (>6 mitoses/50 HPF), may disseminate and/or recur.

Until recently, GISTs were notorious for being resistant to chemotherapy, with a success rate of <5%. Recently, the c-kit tyrosine kinase inhibitor imatinib, a drug initially marketed for chronic myelogenous leukemia, was found to be useful in treating GISTs, leading to a 40-70% response rate in metastatic or inoperable cases.

Patients who become refractory on imatinib may respond to the multiple tyrosine kinase inhibitor sunitinib (marketed as Sutent).