Recurrent Metastatic Gastrointestinal Stromal Tumor - Episode 2
Jonathan Trent, MD, PhD: The use of neoadjuvant or preoperative imatinib in patients with gastrointestinal stromal tumor is presented by a number of studiesMcCullough et al—that support the use of neoadjuvant, as well as adjuvant therapy in patients with gastrointestinal stromal tumor. In my practice, we use preoperative imatinib therapy fairly frequently, and the duration is not written in stone. We typically will treat the patient to maximum tumor shrinkage, which ends up being 6 to 9 months. About 5 months in this case might be a little early, but the patient clearly had substantial tumor regression. At that point in time, proceeding to surgery is very reasonable.
Adjuvant therapy with a primary tumor is supported by the SSG study that found both a recurrence-free survival benefit, and overall survival benefit for patients treated for 3 years versus 1 year. In this specific situation, the patient has a solitary liver metastasisthis would require longer duration therapy, perhaps a lifetime.
For patients in the metastatic setting, there seems to be little benefit in treatment at higher doses than 400 mg per day, if the patient has anexon 11mutation. So, if this patient, in this case, indeed had anexon 11mutation, I would have initiated therapy with a 400 mg per day dose of imatinib and continued that postoperatively.
In August 2016, after 2 years, this patient was found to have multiple peritoneal implants and a new solitary liver lesion by CT scan of the abdomen and pelvis. This patient still had a reasonable quality of life, was able to perform his activities of daily living, and was only limited really in strenuous activity. The patient was initiated on therapy with sunitinib 37.5 mg continuous daily dosing.
Transcript edited for clarity.