Understanding Genetic Testing for Hereditary Cancers

CARP invites you to find out more about hereditary cancers and the importance of genetic screening.

Start the conversation. Talk with your loved ones about any history of cancer in your family. Speak with your doctor about the opportunity presented by genetic testing. Help prevent or detect cancers that can be handed down from one generation to the next.

Dr. Kelly Metcalfe frames the issue regarding the advancements and importance of familial genetic screening for hereditary cancer, in this segment from the CARP sponsored Life to Legacy Webinar.

Unlocking the Secrets of Genetics: Empowering Cancer Patients and Their Families

Genetic testing has revolutionized the field of cancer research, enabling scientists to identify unique genetic changes in tumors caused by both hereditary (germline) and non-hereditary (somatic) alterations. This breakthrough technology has not only paved the way for personalized treatment options but also holds immense potential for identifying specific genetic mutations linked to an increased risk of certain cancers.

When it comes to cancer, knowledge is power. The results of genetic blood testing can significantly influence treatment options, and they have the potential to impact family members who may have inherited the same genetic mutation. For those found to carry a genetic mutation associated with an elevated risk of developing a particular type of cancer, seeking advice from a genetic counselor becomes crucial. These medical professionals possess specialized training to help individuals understand the implications of genetic testing and explain what the DNA changes may mean for their health and that of their family.

Genetic testing can unlock a range of management options for those at increased risk. Regular cancer screenings are recommended to detect the disease at its earliest stages. Preventative medications may be prescribed to reduce the risk of cancer development. In some cases, risk-reducing surgeries might be considered. These proactive measures are particularly important if a specific gene mutation has already been identified in a close relative or if there is a strong history of cancer in the family.

It is vital to recognize that genetic mutations can affect both men and women in a family. Consequently, all family members should have access to genetic counseling and testing. By ensuring comprehensive evaluation, families can make informed decisions about their health and take proactive steps to manage their cancer risk.

Different genetic tests are available based on the individual’s circumstances and their cancer journey. Tumor testing is performed to identify genetic alterations specific to the cancer itself, providing valuable insights for targeted therapies. Blood testing, on the other hand, focuses on germline mutations that could be inherited within the family. Each type of test serves a distinct purpose in guiding treatment decisions and understanding familial cancer risks.

One prominent example of a hereditary genetic mutation associated with increased cancer risk is BRCA1 and BRCA2. Approximately 10% of people diagnosed with cancer have germline (hereditary) BRCA1 or BRCA2 mutations. These mutations significantly elevate the lifetime risk of developing certain types of cancer.

For individuals with BRCA1 mutations, the lifetime risk of breast cancer ranges from 37% to 62%, and the risk of ovarian cancer ranges from 11% to 23%. BRCA2 mutations carry a lifetime risk of breast cancer ranging from 60% to 90% and ovarian cancer ranging from 45% to 85%. Gentlemen, take note, there is an increased risk of male breast cancer, with a lifetime risk of 0.1% to 10% for individuals with BRCA1 and BRCA2 mutations. Metastatic cancer patients also show a higher prevalence of germline BRCA mutations. Approximately 5% of metastatic patients have germline BRCA2 mutations, while 0.8% have germline BRCA1 mutations. These mutations confer a lifetime risk of approximately 30% for BRCA2 carriers, while the risk is slightly increased for BRCA1 carriers.

Understanding familial cancer patterns is crucial for identifying individuals who may benefit from genetic testing. If one or more family members on the same side have had breast, ovarian, prostate, or pancreatic cancer, it is recommended to speak with a genetic counselor. Additionally, individuals with specific cancer diagnoses or other indicators, as outlined by medical professionals, should seek genetic counseling. Genetic counselors can help individuals weigh the pros and cons of genetic testing and provide information on the implications of DNA changes for their health and that of their family.

By starting the conversation within families and then harnessing the power of genetic testing and counseling, individuals and their families can make informed decisions about cancer management, including personalized treatment options and proactive measures to reduce the risk of cancer development. Genetic testing is an invaluable tool that empowers patients and their loved ones to take control of their health and pave the way for a brighter future in the fight against cancer.

Patient Story – Yelena Aizenberg on ‘Morning Zoom’ with Sam and Jane

Online Resources for More Information:

National

Canadian Cancer Society – Genetic Testing
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 help also help 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.

British Columbia