We all carry the same genes.  Some of those genes are responsible for cell division in certain areas of our bodies. Mutations in those genes can affect the carrier's ability to ward off or fight breast, ovarian and prostate  cancer. Depending on the gene that is mutated and the particular mutation within that gene, the cancer risk varies. Some of those mutations cause a very high cancer risk in carriers.  We call these 'risky genes'.  There may also be higher risk of some other types of cancer.  

See a list of risky genes



A minimum of 5-10% of breast and prostate cancer and 10-15% of ovarian cancer is hereditary.

Up to 1 million Canadians living today have been or will be diagnosed with hereditary breast, ovarian or prostate cancer, based on the most conservative statistics.  Hereditary cancer is often downplayed but, to put this in perspective,  this is many times more people than have multiple sclerosis! 


An inherited predisposition to a high risk of breast, ovarian and prostate cancer and slightly higher risks of some other types of cancer due to the presence of one or more germline mutations in one or more of the genes that fall under the HBOC syndrome umbrella

Hereditary cancer is diagnosed much more often in affected families

Hereditary cancer is diagnosed at younger ages.

Hereditary cancer tends to be more aggressive, which can make it harder to treat

The risky genes that cause hereditary cancer can be passed to children

Hereditary cancer has a higher rate of recurrence

There is a higher chance of a second primary hereditary cancer

Hereditary cancer is more prevalent in certain ethnic groups, such as the Ashkenazi Jewish

Hereditary cancer is not well-funded.  This has resulted in a lack of awareness, specialized services and resources

Health recommendations may vary slightly, depending on the region.

Early screening
is recommended to catch cancer early, when it's most treatable. This includes breast and ovarian cancer screening from the age of 25 and prostate cancer screening from the age of 40.  Depending on the mutation carried, other types of cancer screening may also be recommended.

Chemoprevention  In some cases, chemoprevention may be recommended, usually in the form of tamoxifen or a similar drug that reduces estrogen. Oral contraceptives may be recommended to reduce ovarian cancer risk.

Preventative surgery  The method known to reduce cancer risk the most is preventative surgery, in the form of double-mastectomy and ovary/fallopian tube removal.

What is HBOC syndrome?

Lifestyle ChangesThere is increasing evidence to show that positive lifestyle changes, in the form of increased exercise and healthy eating, reduce cancer risk.