Resources on genetic and genomic testing

Genetic and genomic testing are common terms you hear when discussing breast cancer risk and treatment options. The two terms sound very similar but mean different things. Below you will find information on what these two testing options are, how they affect you and your family, and how these tests are accessed across Canada.

Genetic testing

What is genetic testing?

Are there any mutations in your DNA that cause you to be at a higher risk of developing breast cancer?

Genetic testing for breast cancer looks at your genetic risk of developing breast cancer. The most well-known genetic mutation is the BRCA mutations: BRCA1 & BRCA2, but in reality, there are 14 different genetic mutations linked to breast cancer.

Receiving a positive result for a breast cancer related gene mutation means you have an increased risk of developing breast cancer and possibly other types of cancer as well. If you have a gene mutation and you develop breast cancer, it is commonly known as hereditary breast cancer.

Hereditary gene mutations are part of your DNA and therefore can be passed down through your family. If you have a positive gene mutation it means that your family members may also have the same mutation and therefore may also be at a higher risk of developing cancer.  

Accessing genetic testing in Canada

Accessing genetic testing in Canada can be challenging. Each province has its own set of eligibility criteria for people looking to receive genetic testing. Factors include your personal and family history of cancer. Find your province’s criteria here to see if you are eligible for genetic testing.  

Genetic testing is usually performed using a blood sample or cheek swab. While the test is simple, wait times to see a genetic counsellor and receive testing can take anywhere from 1 to 3 years. Once you do, it can take anywhere from 1 to 6 months to get the results of your test.

Accessing private genetic testing

There are many private genetic testing options available to individuals. These are often called “direct-to-consumer” tests. But not all direct-to-consumer tests are created equal. Some popular ancestry-based tests are marketed for healthcare genetic testing, but they are often not as in-depth as medical testing. This means that the results may not be accurate.

If you are considering seeking genetic testing privately, it is important to find a company that offers access to a qualified genetic counsellor. There are currently two companies that offer qualified health-related genetic testing for a fee: Invitae and Color.

What does a genetic counsellor do

A genetic counsellor will discuss all your questions and concerns about what a positive result can mean for you and your family’s risk. See our questions for genetic counselling here.

Choosing to get a genetic test is a personal choice. Your counsellor will talk about the benefits and drawbacks of genetic testing. They will also explain what will happen next if you do receive a positive genetic test.

Resources and information about genetic mutations and testing

Here are more resources and information about genetic testing in Canada:

Genomic Testing

What is genomic testing?

While genetic testing looks at your risk of developing cancer, genomic testing looks at features that can provide information about the cancer itself. It can look at specific markers or mutations within the tumour that may be helping drive its growth. Knowing more about these features can help inform what treatments will work best for your cancer.

What types of genomic testing is available?

Treatments for breast cancer are becoming more personalized as we begin to understand some of the common features and mutations that make up the tumour’s DNA.

Tests like Oncotype DX™, Prosigna ™, EndoPredict ™ and MammaPrint ™ all look at the activity of specific genes within the tumour to predict the likelihood of cancer recurrence. Your score can help inform whether your oncologist will recommend further chemotherapy after your surgery. These tests focus specifically on early-stage hormone receptor (HR) positive breast cancers.

Genomic testing can also be used to identify whether newer breast cancer treatment drugs will be effective for your type of cancer. For example, alpelisib (Piqray) is a newer breast cancer drug that is used to treat HR+, HER2- metastatic breast cancers that have a PIK3CA mutation. More and more treatment drugs are being developed that can precisely target these features within the cell of the cancer. Knowing whether you have these mutations is important in determining whether the treatments will work for you.

Accessing genomic testing

Oncotype DX and other recurrence predictor tests are funded by various Canadian provinces. For more information on these tests, read our Advocacy Guide: Accessing Genomic Testing in Canada.

Genomic testing for new drug therapies is still in its infancy and it may be a challenge to get the proper testing for these new treatments. To learn more, read our report “Precision Oncology and Breast Cancer: Considering Canada’s approach in an evolving landscape”.