Understanding Genes and Hereditary Cancer Risk

This video explains genes, hereditary cancer, and how genetic testing can help you and your healthcare providers plan your care. It also explains how genetic testing may affect your family.

When we say family, we mean family members related to you by blood.

Our bodies are made up of millions of cells. Inside each cell is our DNA. Our DNA is organized into genes, which have the spelled-out instructions for how our bodies grow and develop.

Genes come in pairs. We get one copy from each of our parents. Each gene has a specific job. Some genes help protect us from developing cancer.

When there's a change in the spelling of a gene, the gene may stop working the way it should. This is called a gene mutation.

Some gene mutations may increase your risk of developing certain cancers, but having a gene mutation doesn't mean you'll definitely develop cancer in your lifetime.

Most cancer happens by chance or is caused by aging, environmental factors, or lifestyle habits.

Only about 5 to 15% of cancers are strongly hereditary. This means they're caused by a specific mutation in a gene that can be shared with other blood relatives.

Since gene mutations can be shared with blood relatives, there are certain signs we can look for in a family to see if there's a risk for hereditary cancer.

These signs may include your blood relatives having more than one type of cancer, developing cancer before age 50, developing a rare cancer, such as breast cancer in males.

We also look for many generations of blood relatives having the same type of cancer. Sometimes, the specific type or pathology of the cancers in your blood relatives can also give us clues about your risk for hereditary cancer.

Having these signs doesn't always mean there's a gene mutation in your family that will lead to hereditary cancer, but having one or more of these signs means you may benefit from genetic testing.

If you have a gene mutation, this means your biological parents, siblings, and children each have a 50% chance of having this same gene mutation.

For most hereditary cancers, your cancer risk increases if you inherit one mutation from one of your parents. But some genes are recessive, which means you’d actually need to inherit two mutations, one from each of your parents, to have a higher risk for cancer.

People who inherit just one recessive gene mutation typically don't have a higher risk of getting cancer.

Males and females have an equal chance of inheriting and passing down gene mutations.

If you have a gene mutation and plan to have children, there are options to prevent your children from inheriting this mutation. Your genetic counselor can talk with you about these options.

Genetic testing looks at your DNA to see if you were born with a gene mutation that could lead to a higher risk for certain cancers. This is done by looking at a sample of blood or saliva. It usually takes a few weeks to get your results back.

Genetic testing can help you find out your risk for certain cancers, whether you've been diagnosed with cancer or not. It can also help you and your healthcare providers make decisions about your care, like which cancers you should screen for.

Even if you have cancer, genetic testing may be helpful for making treatment decisions or preventing future cancers.

If your genetic test shows that you do have a gene mutation, your family members may want to have their own testing done to find out if they have the same mutation. This information can let them know their own cancer risk and what they can do to manage their care.

There are also limitations to genetic testing. The current technology used for testing may not be able to find all gene mutations. It's also possible that you may have a mutation that you weren't tested for. Even with a negative result, you may still get cancer by chance.

Some people may worry about how genetic test results can be protected, and whether they'll be treated differently, or lose their health insurance based on the results of their genetic test.

Currently, there is a law in place called the Genetic Information Nondiscrimination Act, or GINA. This law protects against discrimination from health insurance or employers.

Legally, genetic test results cannot be used to deny a person's health benefits or a job. But this law doesn't apply to long-term disability and life insurance and has some exceptions.

This means it's possible that disability or life insurance companies can use genetic test results to deny you coverage or raise your premiums.

Health insurance coverage for cancer genetic testing depends on your insurance company and plan and your personal and family history of cancer.

Some insurance companies have guidelines with specific genetic testing criteria. These guidelines can usually be found on your insurance company's website. Contact your insurance company for information about your coverage.

We hope you found this information helpful. If you have any questions, call our office at 646-888-4050.