If GIST returns after surgery to remove a primary tumor, it is called a recurrence. A recurrence can occur near the original tumor site (a “local” recurrence), or new tumors can appear in distant sites. If this happens, these tumors are called metastases (or simply, “mets”). If GIST tumors metastasize, they usually travel to the liver, or to the peritoneum. Metastases to the lymph nodes and lungs are rare, but can occur. Metastases are usually harder to treat than primary tumors.
Gleevec is the standard treatment for unresectable or metastatic GIST. It has been approved for GIST since 2002 in many countries.
Approximately 85% of GIST patients will respond to Gleevec with either significant shrinkage or it will cause the tumors to stop growing (stability). These responses are more durable than many types of chemotherapy, but resistance will eventually develop for most patients. The duration of response depends primarily on mutation type, but also on other factors.
Caution: The Life Raft Group often hears reports of physicians wanting to stop Gleevec in patients with metastatic disease who have been stable for several years. With rare exceptions, this practice is not recommended and can result in tumor growth.
The 15% of patients that do not initially respond to Gleevec are said to have primary resistance to Gleevec. Some of these patients may respond to Sutent and other targeted treatments.