Recurrent Metastatic Gastrointestinal Stromal Tumor - Episode 1
Jonathan Trent, MD, PhD: A 64-year-old Caucasian male presents to the emergency room with fatigue and abdominal pain. He has no significant past medical history other than well-controlled hypertension that is managed with a beta blocker; he has no significant family history. An abdominal CT scan is performed and this reveals a 12-cm gastric mass involving the cardia and fundus, as well as a 7-cm solitary liver tumor.
A biopsy was performed revealing a gastrointestinal stromal tumor, or GIST, that was KIT-positive by immunohistochemistry, and found to have anexon 9mutation. The tumor was also found to be high-grade, with a greater than 5 per 50 high-power field mitotic rate. The patient was initiated on therapy with imatinib at the 600 mg per day dose; this was well toleratedthe patient maintained therapy for 5 months. At that time, the patient had another CT scan performed of the abdomen that revealed decrease in size of the solitary liver metastasis from 7 cm to 4 cm, with relative stability of the gastric mass. The patient was referred to a surgical oncologist who performed an R0 resection with negative margins of both the liver metastasis and the primary tumor in the stomach. Postoperatively, the patient recovered and was placed on imatinib 800 mg per day.
Patients with gastrointestinal stromal tumors present with a variety of different symptoms, largely depending on the location of the primary tumor. This patient had a primary tumor in the stomach. The patient presented with fatigue, probably related to anemia, as well as abdominal painthis presentation is consistent with a gastrointestinal stromal tumor in this anatomic location.
This patient with GIST was initially treated with 600 mg per day of imatinib, underwent surgical resection and postoperatively was placed on 800 mg per day of imatinib. This management is supported by the GIST metaanalysis that found that patients who have anexon 9mutation benefit from higher doses than 400 mg per day of imatinib, in terms of not only progression-free survival, but overall survival as well.
Transcript edited for clarity.