Medical professionals do not know exactly what causes most gastrointestinal stromal, or GIST, tumors, according to the American Cancer Society. However, there are certain factors that can increase the risk of getting a GIST tumor. One risk factor for a GIST tumor is a family history, though this is rare.
Scientists do know that some GIST tumors come about because of changes in the genes, specifically the c-kit or the PDGFRA genes, but not both, says the American Cancer Society. Other GIST tumors do not show any changes in either of these genes.
Risk factors for GIST tumors include being older, says the American Cancer Society. These tumors rarely strike people who are younger than 40 and are seen in people who are middle-aged to elderly. People who have neurofibromatosis type 1, or von Recklinghausen disease, are also more at risk for GIST tumors. These people often have benign tumors over their bodies as well as cafe au lait spots. They are also at higher risk for other sorts of cancers.
People who have the rare disease Carney-Stratakis syndrome are also at higher risk for GIST tumors, as well as tumors called paragangliomas, reports the American Cancer Society. These tumors affect the nervous system. Unlike most GIST sufferers, people with Carney-Stratakis syndrome contract GIST tumors while they're still in their teens and 20s.