Gastrointestinal stromal tumors (GISTs) are sarcomas that are found in parts of the digestive system. Sarcomas are types of cancer that grow in bone or soft tissues.
New cancer treatments have shown promising results for many people with GISTs. Researchers are focusing on targeted therapies and tumor genotyping. Clinical trials are also available for people interested in experimental therapies.
Targeted therapy is a type of treatment that better identifies and attacks cancer cells. Instead of destroying all of the body’s cells, targeted therapies pinpoint specific proteins that are either overactive or underactive. As a result, the healthy cells remain largely intact while the unhealthy or cancerous cells are destroyed.
Some targeted therapies are already available. Others are currently being studied in clinical trials. These drugs mostly target the KIT or PDGFRA proteins.
Targeted therapies that are tyrosine kinase inhibitors (TKIs) have been particularly useful. Drugs currently being used as targeted therapies for GISTs include:
- imatinib (Gleevec)
- sunitinib (Sutent)
- regorafenib (Stivarga)
- ripretinib (Qinlock)
Some of the clinical trials combine a drug that’s already available with a new drug. Other trials are looking at how specific new drugs work alone in treating GISTs.
Medications currently being studied for GISTs include:
- sorafenib (Nexavar)
- nilotinib (Tasigna)
- dasatinib (Sprycel)
- pazopanib (Votrient)
- ponatinib (Iclusig)
- binimetinib (Mektovi)
Some treatments have been shown to stop working over time, and researchers are trying to determine why and what factors they could change to prevent this. Possible factors include:
- duration of the targeted therapy
- order in which you the take medicine and have surgery
Though some very small tumors (usually 2 centimeters across or less) may not grow and only need regular monitoring, many larger tumors will need to be removed with surgery.
Before surgery, doctors usually perform a biopsy to test for mutations in the KIT and PDGFRA genes. This helps determine which therapies may work best alongside surgery, if needed.
If there is a risk of tumors recurring, further treatments such as targeted therapies may also be needed.
If the tumor is much larger or is located in an area that makes it harder to remove, surgery may not be the first line of treatment.
The goal of immunotherapy is to stimulate the body’s immune system to help fight the cancer. Two main types of immunotherapy being tested for use with GISTs include immune checkpoint inhibitors and monoclonal antibodies.
Immune checkpoint inhibitors
Cancer cells may use immune system checkpoints to avoid being detected and attacked. Inhibiting these checkpoints can alert the body that something is wrong and start an immune response.
Two of these are currently being tested for use with GISTs: nivolumab (Opdivo) and ipilimumab (Yervoy).
Monoclonal antibodies mimic the body’s own immune system proteins. They attach to cancer cells and bring them to T cells (a type of immune cell) to alert the body that it needs to begin an immune response.
Researchers are making steady progress toward developing treatments for gastrointestinal stromal tumors. They are studying new targeted therapies to address more genetic mutations and helpful proteins. This also includes tumor genotyping.
Researchers have started to find connections between the genetic makeup of GISTs and how they react to certain targeted treatments. They’re investigating how to use these genotype profiles to find better treatments.
Certain clinical trials are only recruiting people with particular mutations. Others are studying treatments in people with a particular mutation in their GIST versus those without that mutation.
Clinical trials evaluate how well a new treatment works before it’s released to the general public. If you enroll in a clinical trial, you can receive experimental therapy for your condition. Clinical trials may also study prevention and screening strategies, procedures, or other methodologies.
Clinical trials also offer new options to people who may not have had success with available treatments. Before you decide to enroll in a clinical trial, you should know that the results are unknown. Still, it’s important to remember that all standard therapies were once clinical trials.
Finding a clinical trial
If you’re thinking about participating in a clinical trial, talk with your doctor and healthcare team. They may know of a trial or be able to help you find one.
Many websites can also help you find clinical trials that are right for you, including:
Research into gastrointestinal stromal tumors has been ongoing with many positive steps. Treatment of this type of cancer is improving, as is the outlook for people living with it.
If you’re living with GISTs, talk with your doctor about your goals, treatment options, and potential to join a clinical trial.