Gastrointestinal Stromal Tumors Treatment

In general, treatment is planned according to the following factors:

• Whether the tumor can be completely removed by surgery(resectable)
• Whether the tumor cannot be completely removed by surgery(unresectable)
• Whether the tumor has spread to other parts of the body(metastatic), or the tumor has come back after initial treatment(recurrent).

Surgery is the current standard treatment for tumors that are resectable and have not spread to other parts of the body. GIST tumors that are well-circumscribed and easy-to-access can even be safely and successfully removed laparoscopically by a skilled surgeon.

Targeted therapy is the form of treatment that specifically targets cancer cells using drugs. This treatment is especially useful in case of unresectable and metastatic/recurrent tumors. Tyrosine kinase inhibitors(TKIs) are examples of drugs that are currently employed to treat GISTs, namely, imatinib(Gleevec®) and sunitinib. Targeted therapy is sometimes used preoperatively to shrink a GIST tumor(downstaging) so that it becomes small enough to be removed surgically.

For tumors that are very likely to recur after surgery, doctors now recommend giving imatinib for at least 3 years or until the patient can no longer tolerate the side-effects of the drug.

Tumors that have spread to the liver can usually be treated using Radio Frequency Ablation(RFA), chemoembolization or local ethanol injection.

GIST Prognosis and Staging

The vast majority of GIST tumors are mostly benign carrying an excellent long-term prognosis. There are some cases, however, that the tumor can carry a high malignant transformation potential, meaning that it can be cancerous. 

Sometimes, It may be hard for the doctor to determine how aggressively a GIST will behave. There are certain factors that may predict the tumor’s malignant behavior, namely:

1. Large initial size (>2cm in diameter)
2. Increased mitotic count, that is, number of dividing cells
3. Tumor spreading to distant areas of the body
4. If tumor cannot be completely removed by surgery