BRCA1 and BRCA2 Hereditary Breast and Ovarian Cancer Syndrome

Breast cancer is relatively common in the general population (12% lifetime risk) and the majority of cases occur sporadically.  About 5-10% of breast cancer is due to an inherited gene change.  Mutations in the genes BRCA1 or BRCA2 are the most common cause of hereditary breast and ovarian cancer (HBOC) and BRCA1 and BRCA2 mutation carriers have a significant increased lifetime risk for breast and ovarian cancer in addition to other cancers. Risk-reducing surgeries and, for some women, chemoprevention, can reduce mortality from breast and ovarian cancers in both BRCA1 and BRCA2 carriers. Individuals with family histories of breast or ovarian cancer that are at high risk (generally >10%) to carry a BRCA1 or BRCA2 gene mutation can be offered referral to genetics services for a discussion of the benefits, harms and limitations of genetic testing, while women whose family histories suggest a low risk of carrying a BRCA1 or BRCA2 gene mutation can be reassured and offered screening following provincial guidelines. (For more information see the comprehensive GEC-KO Messenger or the concise GEC-KO on the run)

This point of care tool has two parts. Part I of this tool is used to predict which individuals should be referred for genetic counselling due to increased risk for a hereditary breast cancer syndrome including but not limited to hereditary breast and ovarian cancer (HBOC) syndrome caused by mutations in BRCA1 and BRCA2 genes.  Part II of this tool is used to identify individuals who are at high risk to carry a mutation in BRCA1 or BRCA2 genes.

Links to your provincial breast screening program can be found here.

GEC-KO aims to aid the practicing non-genetics health professional by providing informed opinions regarding genetic/genomic conditions, services and technologies that have been developed in a rigorous and evidence-based manner with periodic updating.  The content on the GEC-KO site is for educational purposes only.  No resource should be used as a substitute for clinical judgement.  GEC-KO assumes no responsibility or liability resulting from the use of information contained herein.