This video offers general information about hereditary cancer and genetic testing.

Your body is made of millions and millions of cells.

There are around 20,000 genes inside each cell.

Each gene has a special job and tells your body how to grow and how to function.

Some genes determine your eye color, your hair color or how tall you are.

Other genes protect your body from developing cancer.

If these genes are working properly, they help protect you from cancer.

If they are not working properly, you have a higher chance of developing cancer.

Cancer is common.

More than 40% of Canadians will get cancer in their lifetime.

Because cancer is common, it's not unusual to have some family members with cancer.

70 to 80% of cancers happen by chance.

These cancers are caused by things like age, lifestyle, and environment, and are called sporadic cancer.

About 15 to 20% of cancers have a familial cause.

Familial cancers can also be caused by age, lifestyle, environment and chance, just like sporadic cancers.

But, small genetic factors may also play a role in developing familial cancer.

Unfortunately, we cannot test for the genetic factors that cause familial cancer.

Only 5 to 10% of cancers have a hereditary cause.

These cancers happen because of a gene that is not working properly and can be passed along in a family.

Genetic testing can be used to find out if the cancer in your family has a hereditary cause.

Clues that the cancer in your family might be hereditary are: cancer diagnosed at a young age; rare types of cancer, such as breast cancer in men or ovarian cancer in women; more than one type of cancer in the same person; a pattern of cancer in many generations of the family; belonging to certain ethnic groups; or, a family member that has an abnormal – positive genetic test result.

Genetic testing to look for a hereditary risk factor for cancer is usually done by taking a blood sample and looking for a change in genes that causes the type of cancer in your family​

Sometimes other samples, like cheek swabs or saliva, are needed for genetic testing.

Rarely, testing is done on a tumor sample.

If you have already had cancer, genetic testing might tell you why you got cancer.

If you are still being treated for cancer, it might be used to make treatment decisions.

It might also tell you if you have a high chance of getting other types of cancer and if there are ways to lower your chance of getting cancer or finding it early.

If a hereditary cause for cancer is found in your family, other family members can also be tested to find out if they have a high chance or average chance of developing cancer, and if there are ways of lowering that chance or finding it early.

If you have had cancer and have a normal negative genetic test result, this might mean you have a familial or sporadic cancer.

Depending on your personal and family history, your doctor will determine what type of cancer

screening is right for you.

It is important to know you do not have to have genetic testing.

You might feel that finding out if you have a hereditary cause for cancer is helpful for you or your family.

Or you may not want to have this information and decide not to have testing.

Genetic testing is a personal decision.

We hope that this video has helped to explain some information about hereditary cancer

 and the option of genetic testing.