What is The Screen Project?
The Screen Project is a Canadian National initiative to make BRCA1 & BRCA2 screening available to all Canadians over 18 years of age at an accessible price. As part of The Screen Project, you will also help our team of researchers at the Familial Breast Cancer Research Unit of Women's College Hospital evaluate the benefits of population-based genetic testing. We hope that our study will reduce the mortality from breast, ovarian, prostate and other cancers.
Why Should You Care?
Breast cancer is the most common cancer among Canadian women and affects approximately 1 in 9 women and ovarian cancer affects another 1%. In men, prostate cancer will affect about 1 in 7 men. We do not understand the cause of most cancers, but approximately 5-10% of all breast and ovarian cancers are hereditary and due to a mutation in a gene that is passed down from one generation to the next.
Two genes, BRCA1 and BRCA2, are strongly associated with breast, ovarian and prostate cancers. Everyone has two copies of the BRCA1 and BRCA2 genes, which we inherit from each of our parents. Their function is to help prevent cancer in specific parts of the body. If the BRCA1 or BRCA2 gene is not working properly (due to genetic change or mutation), then there is an increased risk for cancer. BRCA mutations predispose women to a higher lifetime risk of breast (up to 80%) and ovarian cancer (up to 20 - 40%). Men with a BRCA mutation are at increased risk of developing prostate (up to 35%) and other cancers. It is estimated that one in every 200 Canadians carries a mutation in one of the two BRCA genes. However, members of several groups are more likely to have a mutation than the average Canadian. These groups include:
- Women with a recent or past history of breast or ovarian cancer
- Women with ductal carcinoma in situ (DCIS)
- Men with prostate cancer
- Men and women with pancreatic cancer
- Women and men with a family history of breast or ovarian cancer.
Knowing if you have a BRCA gene mutation can help you, and your doctor better understand your risk of developing certain types of cancers. There are also many management options available to reduce the risk of developing cancer, detecting cancer at an early stage, as well identifying more targeted treatments. It is also important information for your family members, and in many cases cancer can be prevented.
Genetic testing through the Screen Project is based on a saliva sample that is provided to Invitae, our genetic testing partner (details about this process are available in the consent form). Your sample will initially be tested for the BRCA1 and BRCA2 genes. However, you will have the option to request additional testing once you receive your BRCA test results.
Typically, if someone decides to have genetic testing, you can get one of three types of result for each gene:
1. Negative – means the gene looks as it should (i.e. normal) and no changes or mutations were found in the genes tested. This does not mean that you cannot develop cancer and any future cancer screening recommendations should be based on your personal and family history.
2. Positive – means a significant, cancer-causing change (called a ‘pathogenic’ mutation) has been found in the gene and is thought to cause it not to function properly. This is believed to increase cancer risk in those who carry the mutation, but there are management options.
3. Variant of Uncertain Significance (VUS) – means there is a minor variation found in the gene, but it is not clear at this time whether this particular variation causes an increased risk of cancer in those who carry it, and if so, by how much. We all carry minor genetic changes in our genetic information, therefore, most VUSs are not cancer-causing, but it is possible that over time a VUS may be reclassified. Typically, for people with a VUS in a gene, their medical management is based on their personal and family history.
If someone is found to carry a mutation in the BRCA1 or BRCA2 genes (ie. tests positive), this may help explain why they got cancer or explain their family history of cancer. This will also mean that they could be at increased risk of developing cancer in the future. It is important to know that testing positive is not a diagnosis and it does not mean you will get cancer. Armed with this genetic information, BRCA1 and BRCA2 gene mutation carriers can make informed decisions about how they would like to manage this increased risk of cancer. All participants found to carry mutations will speak with the study genetic counsellor to discuss their cancer risks and management options. Our clinical research team will also refer all newly identified BRCA1 and BRCA2 gene mutation carriers to their local genetics clinic to further review the cancer risks, management options and for future follow-up.
If someone is found to carry a mutation in one of the genes, this can also have implications for family members. Any biological children or siblings (both male and female) will have a 50/50 chance of carrying the same genetic mutation and predisposition to cancer. However, this does not mean that they will get cancer. Having a positive mutation result also likely means that one of the parents of the participant must have carried the same gene mutation, as may some of their relatives. Genetic testing is typically available to all adult, at-risk family members through a local genetics clinic.
To learn more about hereditary breast cancer and understanding the genetic testing results, you can watch the below short videos on YouTube:
Credit: Jewels in Genetics
What are the study benefits?
The benefits include receiving a genetic test that most Canadians are not eligible to receive under their provincial programs. Furthermore, this genetic information may allow you to better manage your health and understand your risks for developing specific types of cancers. BRCA mutation carriers identified through the study will receive standard, one-on-one genetic counselling and be given information about their cancer risk and the most current management options, and they will have access to long-term genetic care locally. Being identified as a gene mutation carrier may mean access to intensified screenings, taking medications to reduce cancer or preventative surgery that was not previously available. The study may also benefit family members by helping to clarify the level of cancer risk in the family, as well as give relatives the information so they too can make informed decisions about their health. In addition, should you wish to have testing for additional genes (other than BRCA1 and BRCA2) related to hereditary cancers, this option is available through the Screen Project at no extra cost, after you receive your BRCA1 and BRCA2 genetic testing results. For more information regarding this additional testing, please see the study consent form.
Are there any harms in participating?
It is also important to be aware that there are potential risks from participation in the study. The main risks are primarily of a psychological nature. For instance, those who receive a positive results and are at an increased risk of cancer, may feel a host of different emotions. However, getting an uninformative result can also leave people feeling uncertain and worried. Counselling will be provided individuals who are identified as BRCA mutation-carriers through Women’s College Hospital. Counselling for those who receive a negative or inconclusive result will be provided by Invitae or Women’s College Hospital as requested by the individual.
There are also potential non-medical implications from your genetic test result. In the past, there had been concern about the impact of a positive genetic test result on future insurability and/or employability. As of May 4, 2017, the Genetic Non-Discrimination Act (GNA), formerly known as Bill S-201 was passed into law in Canada. This law protects individuals from the use of genetic test results for means of discrimination by potential or existing insurers. Under GNA, insurance providers cannot request or require that a person undergo genetic testing or disclose previous and/or future genetic test results in the clinical or research setting. However, GNA does not prohibit insurers from using information about pre-existing or previously diagnosed medical conditions. Family history is also not protected by GNA. Therefore, there may be circumstances that are not covered by the Act, as well as the rules and protections may be different in other countries.