Hereditary Cancer

Approximately 5-10% of all cancers are hereditary. An additional 10-30% of individuals may be at increased risk because they have close family members who also had cancer, suggesting a familial link, even though no specific hereditary link was found.

There are many types of familial cancers. For example, in certain families, women have a higher propensity to develop breast and/or ovarian cancer. This is known as Hereditary Breast and Ovarian Cancer syndrome (HBOC), which is often caused by an inherited mutation in either the BRCA1 or BRCA2 gene (BRCA1/2). Harmful variants in BRCA1/2 may lead to an increased chance of developing other cancers as well, such as fallopian tube, peritoneal, melanoma, pancreas, and/or prostate cancer. More than 2,600 harmful mutations have been found in BRCA1/2.

Analysis of hereditary cancer genes involves a step-by-step look through the DNA of each gene for changes, known as mutations. Our panel looks at the 84 more common genes associated with increased risk of developing hereditary breast, ovarian, uterine, colorectal, gastric, prostate, melanoma, and pancreatic cancers.

Genetic testing is most commonly performed on blood but can also be performed on saliva, tissue, or banked DNA.

It is estimated that 1/2 of men and 1/3 of women will develop a cancer in their lifetime. 5-10% of cancers are hereditary, which means we can tell you more about your risks ahead of time.

Genetic testing may be appropriate if you or a close family member has:

• Breast, colorectal, or uterine cancer diagnosed before age 50
• More than one type of cancer
• Cancer in both of a set of paired organs (for example, both kidneys or both breasts)
• Certain types of cancer including ovarian, pancreatic, metastatic prostate, intraductal prostate, medullary thyroid, triple-negative breast or male breast cancer)
• 10+ gastrointestinal polyps
• Breast or high grade prostate cancer (Gleason score >7)
• Ashkenazi Jewish ancestry

• Once the sample is received at LifeLabs Genetics, the team will schedule a pre-test genetic counselling session for the patient and, optionally, the ordering physician
• Sample analysis by LifeLabs Genetics’ laboratory partner, Invitae, takes 4–6 weeks
• The patient is strongly encouraged to attend a post-test genetic counselling session
• Timing estimates do not include time required for healthcare provider appointments, requisitions, consent signatures, sample collection, or courier/shipping times

• Guides surveillance, prevention, and medical management decisions regarding cancer
• Provides opportunities to detect cancer early and improves potential outcome
• Clarifies risks to family members
• Facilitates important discussions with family members

NegativeSample Report
Positive Sample Report
Alternate VUS Sample Report

Results documentation includes the following: A summary of the pre-test genetic counselling session for the patient and the ordering physician

• A copy of the result with an explanatory letter for the patient^* and the ordering physician.
• Possible results include:
  • Positive: A disease-causing mutation was identified. This individual has an increased risk for specific types of cancer. Family members are at increased risk of carrying the same mutation.
  • True Negative: This individual tested negative for a mutation previously identified in the family. This individual’s risk for cancer is not expected to be increased above the general population risk.
  • Uninformative Negative: No disease-causing mutation was identified. If an individual has a personal or family history of cancer, the exact cause of the cancers in the family remains unknown. This individual’s risk for cancer remains increased based on family history assessment. If applicable, testing affected family members could be considered.
  • Variant of Unknown Significance (VUS): A VUS indicates that the pathogenicity (whether a mutation causes a predisposition to cancer) of the variant identified cannot be established. Testing other family members may help clarify the clinical significance. Over time, variants may be reclassified as pathogenic or non-pathogenic.

*Note: the ordering physician has the option to opt out of patients receiving results directly. If this is the case, the patient will be notified that their results are ready and to contact their ordering physician. 

Hereditary Cancer + Counselling Requisition Form

Hereditary Cancer + Counselling Requisition Form French 

Patient consent form English

Patient consent form French

Hereditary Cancer Panel patient brochure

Sporadic vs Hereditary Cancer info sheet

Hereditary Cancer Risks and References

Breast/Ovarian Cancer MD detail aid

Breast/Ovarian Cancer patient brochure

Growing up, Heather Gauthier realized that every woman in her family – her grandmother, mother, and aunts – had been affected by cancer. Heather was 20 years old when her mother passed away with ovarian cancer at the age of 48…

Click here to read Heather’s story..