Treatment Choices for Gastrointestinal Stromal Tumor Based on Tumor Spread

Treatment for gastrointestinal stromal tumors (GISTs) depends mainly on the size of the tumor, where it is, how far it has spread, and how quickly it is growing (its mitotic rate).

Localized, smaller (resectable) tumors

Most small GISTs will need to be treated. But for some very small tumors (less than 2 centimeters across) that are not causing any symptoms, one option may be just to watch the tumor carefully with endoscopy once or twice a year. If it is not growing, you might not need further treatment.

Surgery is the main treatment for most small tumors. The need for further treatment depends on the risk of the GIST coming back after surgery.

Tumors that are small and are not growing quickly typically have a low risk of coming back, so often no further treatment is needed.

The risk of a GIST coming back after surgery is higher if the tumor is larger, if it did not start in the stomach, or if the cancer cells are dividing quickly (have a high mitotic rate). If the doctor thinks that the cancer has an intermediate or high risk of coming back based on these factors, adjuvant treatment with the targeted drug imatinib (Gleevec) is typically recommended for at least a year after surgery. For tumors that are highly likely to come back, many doctors now recommend at least 3 years of imatinib.

Localized, larger (marginally resectable) tumors

Tumors that are larger or in places that make them harder to remove (resect) completely might require more extensive surgery, which could cause health problems later on. Because of this, surgery is not typically the first treatment.

Before starting treatment, it’s important to be sure that the tumor is in fact a GIST, so a biopsy is needed. Once a biopsy is done, treatment with the targeted drug imatinib is usually started to try to shrink the tumor. It is continued at least until the tumor stops shrinking.

If the tumor shrinks enough, surgery might be done if the doctor thinks he or she can remove it safely. Imatinib will likely be continued after surgery to help lower the chance that the cancer will come back.

If the tumor doesn’t shrink enough to make surgery possible, imatinib is often continued for as long as it seems to help. If it's no longer working, sometimes upping the dose can be helpful. If this is no longer helpful, or if the side effects are too severe, the targeted drug sunitinib (Sutent) may be tried instead. If sunitinib is no longer working, regorafenib (Stivarga) may help some patients.

Tumors that are not removable or have spread to distant sites (unresectable tumors)

Treatment options for GISTs that cannot be removed with surgery or have spread (metastasized) depends on why they are unresectable and, if they have spread, how extensive the spread is.

Surgery is not typically the first treatment for these tumors, so before starting treatment, it’s important to confirm that the tumor is in fact a GIST with a biopsy. 

Once a biopsy is done, the targeted drug imatinib is typically the preferred first treatment. It is continued as long as the tumor doesn’t grow (and the patient can tolerate the side effects of the drug). If the tumor starts to grow again, it may respond to increasing the dose of imatinib. If the tumor continues to grow or the side effects from imatinib are too severe, a switch to sunitinib may be helpful. If sunitinib is no longer working, regorafenib may help some patients.

If the tumor shrinks enough with targeted therapy, surgery may then be an option for some patients. This might be followed by more targeted therapy if it is still effective.

If the cancer has spread to only 1 or 2 sites in the abdomen (such as the liver), the surgeon may advise removing the main tumor and trying to remove these other tumors as well. If this is the case, be sure to talk with your doctor about what the goals of treatment are (whether it is to try to cure the cancer, to help you live longer, or to prevent or reduce symptoms), as well as its possible benefits and risks. Usually this should be considered only for tumors that are slow growing or those causing complications such as uncontrollable bleeding.

Other options to treat cancers that have spread to the liver include ablation and embolization to try to destroy these tumors.

Cancers that are no longer responding to the targeted drugs discussed above can be hard to treat. Some doctors may recommend trying other targeted drugs, such as sorafenib (Nexavar), dasatinib (Sprycel), nilotinib (Tasigna), or pazopanib (Votrient), although it’s not yet clear how helpful these drugs are.

Standard chemotherapy drugs are usually not very effective. Taking part in a clinical trial of a newer treatment may be a good option for some people.

Recurrent tumors

When a cancer comes back after treatment, it is called a recurrence. If the cancer comes back (recurs) in or near the place it started, it is called a local recurrence. If it recurs at other sites (like the lungs or liver), it is called a distant recurrence. Treatment options for recurrent GISTs depend on the location and extent of the recurrence.

For most recurrences, treatment with the targeted drug imatinib is probably the best way to shrink any tumors, as long as it is still effective and the patient can tolerate taking it. If the starting dose of imatinib doesn't work, the dose can be increased. Another option is to try other targeted drugs, such as sunitinib or regorafenib.

If the cancer comes back as one or more well-defined tumors, removing or destroying the tumor may be an option. Doctors are still not certain if removing GISTs that come back after treatment helps people live longer. You should discuss the risks and benefits of this treatment with your doctor and family.

If the targeted drugs mentioned above are no longer helpful, some doctors may recommend trying other targeted drugs, such as sorafenib (Nexavar), dasatinib (Sprycel), nilotinib (Tasigna), or pazopanib (Votrient), although it’s not yet clear how helpful these drugs are.

Because these cancers are often hard to treat, you may want to consider taking part in clinical trials of newer treatments as well.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Casali PG, Dei Tos AP, Gronchi A. Chapter 55: Gastrointestinal Stromal Tumor. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 10th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2015.

National Cancer Institute. Physician Data Query (PDQ). Gastrointestinal Stromal Tumors Treatment. 2017. Accessed at www.cancer.gov/types/soft-tissue-sarcoma/hp/gist-treatment-pdq on April 17, 2017.

National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Soft Tissue Sarcoma. V.2.2017. Accessed at  www.nccn.org/professionals/physician_gls/pdf/sarcoma.pdf on April 17, 2017.

Last Medical Review: May 17, 2017 Last Revised: May 17, 2017

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