Inherited cancer syndromes
Inherited cancer syndrome occurs in 5 to 10 percent of all cancer cases in those who inherit a mutation that increases the risk of cancer.
Mutations and Syndromes Discussed in Cancer Care:
BRCA1 and BRCA2 gene mutations
A woman who inherits the BRCA gene mutation (Breast Cancer) has an increased risk of breast and ovarian cancer syndrome. A person who inherits a BRCA mutation has an increased risk of breast and prostate cancer.
Heriditary leukemia and hematologic malignant syndromes
In recent years, researchers have discovered dozens of inherited genetic conditions that can lead to leukemia and related blood diseases, such as myelodysplastic syndrome, acute myeloid leukemia, and aplastic anemia. Large-scale studies in patients with leukemia have not been completed, however, doctors estimate that between 5% and 10% of all cases of leukemia are inherited. Leukemia patients with a family history of the disease should consider genetic testing to determine if they have a hereditary component to their disease. This information affects the patient’s treatment plans. Our hereditary leukemia clinic must care for MD Anderson patients suspected of having one of these conditions.
This syndrome is the result of mutations in the PTEN gene. A woman with this syndrome has an increased risk of breast and cervical cancer. Mutations Women and men are also at increased risk for thyroid cancer.
Familial adenomatous polyposis
This syndrome is caused by mutations in the APC gene. These mutations increase the risk of colon cancer. They also increase the risk of soft tissue tumors and brain tumors.
Most people with Li-Fraumeni syndrome, a rare genetic disease, have mutations in the TP53 gene, which increase the risk of many types of cancer. Soft tissue sarcomas (tumors of fat, muscles, nerves, joints, blood vessels, bones, or deep skin), breast cancer, leukemia, lung cancer, brain tumor, and cancer of the adrenal glands.
Also known as hereditary nonpolyposis colorectal cancer (HNPCC), this syndrome increases the risk of colon cancer due to mutations in mismatched DNA repair genes known as MLH1, MSH2, MSH6, or PMS2. Variations in these mutations can also lead to Muir Torre syndrome or Turquoise syndrome, which in turn increase the risk of certain skin cancers or brain tumors.
Multiple endocrine neoplasias (MEN)
Multiple endocrine neoplasia (MEN) syndromes get their name because they cause people to develop tumors of the endocrine glands. The endocrine system secretes hormones into the bloodstream that regulate many processes in the body. The endocrine system is crucial for regulating mood, growth and development, and metabolism, as well as the processes of sexual function and reproduction. There are two types of MEN syndrome: MEN1 is caused by a mutation in the gene. MEN2A and MEN2B are caused by mutations in the RET gene. All three mutations increase the risk of endocrine system cancer.
Von Hippel-Lindau disease
This disorder, which is caused by mutations in the VHL gene, causes abnormal blood vessel growth (known as hemangioblastomas or angiomas) and increases the risk of kidney and other cancers.
How risk is inherited
As you may recall from science class, the nucleus of every cell in our body contains 23 pairs of chromosomes, which are genes that we say we are. One chromosome in each pair comes from our father, Another came from our mother.
Each chromosome is made up of thousands of genes, which are coded sections of DNA. A change in the order of the DNA that makes up the gene causes the gene to stop working normally. These genetic changes are called mutations.
If your parents have a genetic mutation, that doesn’t mean you definitely have it. Likewise, if you have a genetic mutation, it doesn’t mean your child has it. The odds in each case are 50/50. Each person has two copies of each gene: one inherited from the father (they have two copies of the gene) and one from the mother (there are two copies of the gene). Parents who have a copy of the mutation will check for the mutated gene or the normal gene. A child’s chance of getting a modified version or a normal version is like flipping a 50/50 coin. If the parents have a second child, the child also has a 50/50 chance of inheriting a genetic mutation. Parents have a genetic mutation and increase their risk even if they never developed cancer. A child who does not inherit an abnormal transformation cannot cross it.
If you inherit a mutation that increases your risk of cancer syndrome, it does not mean that you have decided to have cancer. This means that your risk is higher than average. Knowing you have a mutation creates opportunities to lower your risk through cancer screening and other risk reduction measures.
Hereditary cancer syndrome tests
Knowing that you have cancer syndrome or that a close relative is suffering from it, you may want to go online and request one of the genetic tests you read or post. That is not a good idea.
The first thing to do is make an appointment to speak with a genetic counselor, who will discuss your family history and help you determine if the test is right for you. By consulting a genetic counselor, you can be sure that the correct tests will be ordered and the results will be explained correctly.
Genetic testing usually involves a sample of blood or saliva. A specialized analysis in the laboratory can detect changes in the DNA that indicate a mutation. The goal of the test is not just to get the result, but to get the information you use to help reduce your risk of cancer syndrome. For this reason, testing usually begins with a person with this disease. If your relative does not have a hereditary mutation, there is no reason to test your children. If you have a genetic mutation, it can be tested on other members of the family. While genetic testing does not always give a simple yes or no, it is important to consult a genetic counselor.
Children should not be tested if they are not old enough when it makes sense to start cancer screening with a mammogram or colonoscopy or to have surgery to reduce the risk of this disease.