Adjuvant Therapy for GIST

Edwin Choy, MD, director of the Sarcoma Program at the Division of Hematology Oncology at Massachusetts General Hospital, a founding member of Mass General Brigham, associate professor of medicine at Harvard Medical School, discusses adjuvant treatments for patients with gastrointestinal stromal tumors (GIST).

To determine the overall risk value for a patient with GIST, Choy looks at 3 factors, including tumor size, tumor grade, and tumor location.

While not many tyrosine kinase inhibitors typically used to treat GIST have been well studied, Choy also notes that data has shown overall survival can improve for patients with GIST by using imatinib (Gleevec) adjuvant therapy for 3 years.

Transcription:

0:08 | We have a lot of data on how patients do after their GIST is resected. We are able to understand that their risk of developing either a recurrence or metastasis is based on 3 factors based on tumor size. Larger than 5 centimeters is high-risk. Tumor grade, which is largely graded on mitosis, if you see more than 5 mitoses, then we will consider that high-grade. And then tumor location. The best risk for GIST is located in the stomach. But for GISTs that are located in the small bowel or rectum or elsewhere, they have a higher risk of developing metastasis and recurrence.

1:06 | We combine those 3 characteristics to give an overall risk value for a patient. If we find that the risk of developing a recurrence or metastasis is high, given the tumor size, grade, and location, then there is data showing that we can improve overall survival by giving them adjuvant therapy for 3 years of imatinib.

1:38 | The other tyrosine kinase inhibitors typically used to treat GIST have not been as well studied as adjuvant therapy. However, if you do the mutation testing and you show that it does not have typical mutations that are sensitive to imatinib, then, there is less data for using imatinib in those situations.