Intestinal Cancer Prevention
| What Are the Risk Factors for Gastrointestinal Stromal Tumors? |
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A risk factor is anything that affects a person's chance of getting a disease such as cancer. Different cancers have different risk factors. For example, exposing skin to strong sunlight is a risk factor for skin cancer. Smoking is a risk factor for cancers of the lung, mouth, larynx, bladder, kidney, colon, and several other organs. But risk factors are not absolute. Having a risk factor, or even several risk factors, does not mean that a person will get the disease. And many people who get the disease may not have had any known risk factors.
Currently, there are very few known risk factors for GIST.
In rare cases, GISTs have been found in several members within the same family. These family members inherited a gene mutation that leads to GIST (see next section). But most GISTs are sporadic (they are not passed down from generation to generation), and their cause is unknown.
Neurofibromatosis is a disease that usually runs in families and is characterized by many neurofibromas (benign tumors that form in nerves under the skin and in other parts of the body), as well as many tan or brown spots on the skin, including their underarm area which is an unusual location for moles in most other people. Some people with this condition also develop brain tumors and GISTs.
Familial gastrointestinal stromal tumor syndrome is a rare, inherited condition leading to increased risk of developing one or more GISTs. The mutated gene passed from one generation to the next in the familial gastrointestinal stromal tumor syndrome is usually the c-kit gene. This is the same gene that is mutated in sporadic GISTs. But people with the familial form have a mutation in all the cells of their body, whereas only the GIST cells are affected by this mutation in the sporadic form. Very rarely, another gene, the PDGFRA gene (instead of the c-kit gene) is responsible for gastrointestinal stromal tumors in some families. People with this inherited condition tend to develop GISTs at a younger age than do sporadic GIST patients and are more likely to have multiple GISTs. They may also have skin spots similar to those in neurofibromatosis. Until recently, when tests for c-kit gene and PDGFRA gene became available, some of these people were mistakenly thought to have neurofibromatosis.
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