What is Mainstreaming Cancer Genetic testing in BC?
“Mainstreaming” is a technical term for a new genetic testing approach for individuals with a cancer diagnosis that meets a specific set of criteria (see below). It allows those from your cancer care team (e.g. oncology NP, oncologist, surgeon, or any other doctor) to order genetic testing directly, rather than through a genetic counsellor at the BC Cancer Hereditary Cancer Program (HCP), which can delay the process. Genetic testing through mainstreaming is done with a blood test, which may help your team figure out the cause of your cancer. A gene change (mutation) typically is being looked for in the BRCA genes, and other genes.
Why Do We Need Mainstreaming?
Mainstreaming was put in place so genetic testing could become part of a cancer patient’s routine care. Mainstreaming also means that a referral to the BC Cancer Hereditary Cancer Program (HCP) for genetic testing may not be required for patients with cancer. This can help alleviate long wait times for an appointment. Having mainstreaming in place means that you can go through the genetic testing process with your cancer care team who you are already familiar with. Plus, sometimes a genetic test result may be needed in a timely manner to assist with cancer care decisions.
Who is Eligible?
There is a specific list of criteria that identifies who is recommended to have genetic testing as part of the mainstreaming approach.
These include:
Breast Cancer that is HER2-negative
Breast cancer diagnosed before age 35
Two primary breast cancers, with at least one diagnosed before age 50
Triple negative (ER-PR-HER2-) breast cancer diagnosed before age 60
Breast cancer diagnosed or colorectal cancer before age 50 AND no family history known (due to adoption)
Ovarian, fallopian tube or peritoneal cancer diagnosis
Male breast cancer diagnosis
Pancreatic cancer diagnosis
Prostate cancer that has spread or is spreading to other parts of the body (metastatic)
Ashkenazi Jewish ancestry with a breast, ovarian, pancreatic, or prostate cancer diagnosis, either personally or in the family
It is important to remember that this list of recommended criteria will likely change as more research is done and we learn more about the role hereditary cancer mutations in the development and treatment of cancer.
Do I Have to Participate in Mainstreaming if I Have Cancer?
In short, No! The decision to have genetic testing is always yours to make. Your cancer care team will provide information about why the testing can be helpful and then you can decide if genetic testing is right for you.
How Does it Work?
Genetic testing through mainstreaming is done using a blood sample and the results take about 8-10 weeks to receive. Your cancer care team will share the results directly with you. If you carry a genetic mutation, you will receive a referral to the BC Cancer Hereditary Cancer Program. The timeframe for this appointment can vary and generally is based on the urgency of the situation. Most appointments with HCP are done by phone and take between 15 and 45 minutes. You will receive more information and future cancer risk management options at this appointment, as well as referrals to any necessary screening clinics.
How Likely is it that my Cancer is Caused by a Genetic Mutation?
Most people who have cancer do not have a genetic mutation that is passed down (inherited) in a family. Currently, we believe that 5-10% of cancers are caused by gene change (aka mutation). If you are found to carry a mutation, this information can sometimes help you and your cancer care team plan your cancer treatment. It will also give you information about your risk of future cancers and help guide your cancer screening or risk-reducing options. Finally, it also gives your family members the option to have genetic testing to learn if they also have a higher risk of cancer and this can help guide their cancer screening and risk-reducing options as well.
Final Thoughts: Mainstreaming Genetic Testing is Not for Everyone
The main takeaway is that mainstreaming is only for those who have a cancer diagnosis.
If you do not have a cancer diagnosis, but there is a family history of cancer in multiple family members at young ages or a known cancer gene mutation is in the family, then a referral to the BC Cancer Hereditary Cancer Clinic (HCP) is available and can be made by a primary care practitioner (like a GP or NP) or through self-referral. Those with Jewish ancestry, with or without a family history of cancer, can also currently (until March 2026) access free testing from the GET WISE pilot program at BC Cancer. If you aren’t eligible for any of these programs, but would still like to get tested, private and research-based testing options are also available. BRCAinBC offers an overview of options on our website.
Further Reading and Resources on Mainstreaming
Video on Hereditary Cancers by HCP
Overview of Mainstreaming
https://cancergeneticslab.ca/genes/hereditary-cancer-panel/
https://cancergeneticslab.ca/hereditary/#MAINSTREAMED_HEREDITARY_CANCER_TESTING -
Overview of Genetic Testing from HCP
Mainstreaming – Positive Result Info Sheet
https://cancergeneticslab.ca/wp-content/uploads/2023/11/Mainstreaming_PositiveResultInfoSheet.pdf
BC Cancer Hereditary Cancer Program
http://www.bccancer.bc.ca/our-services/services/hereditary-cancer#Eligibility
BC Cancer High Risk Clinic
http://www.bccancer.bc.ca/health-professionals/clinical-resources/hereditary-cancer/high-risk-clinic -
BC Cancer HCP – What to Expect
http://www.bccancer.bc.ca/our-services/services/hereditary-cancer#What--to--Expect
Mainstreaming Genetic Testing Requisition Form for Healthcare Providers
References
Bouras A, Guidara S, Leone M, Buisson A, Martin-Denavit T, Dussart S, Lasset C, Giraud S, Bonnet-Dupeyron MN, Kherraf ZE, Sanlaville D, Fert-Ferrer S, Lebrun M, Bonadona V, Calender A, Boutry-Kryza N. Overview of the Genetic Causes of Hereditary Breast and Ovarian Cancer Syndrome in a Large French Patient Cohort. Cancers (Basel). 2023 Jun 29;15(13):3420. doi: 10.3390/cancers15133420. PMID: 37444530; PMCID: PMC10341368.
BC Cancer. (2024). Mainstreamed Genetic Testing. BC Cancer. http://www.bccancer.bc.ca/health-professionals/clinical-resources/hereditary-cancer#Resources
BC Cancer. (2024). Mainstreamed Hereditary Cancer Testing. Cancer Genetics and Genomics Laboratory BC Cancer. http://cancergeneticslab.ca/hereditary/mainstreamed-testing/
Monaghan, A., Copson, E., & Cutress, R. (2024). Hereditary genetic testing and mainstreaming: A guide for surgeons. The Annals of the Royal College of Surgeons of England, 106(4), 300-304. https://doi.org/10.1308/rcsann.2024.0029