BRCA genes (BRCA1 and BRCA2) are normally involved in cancer suppression. Mutations on either of these genes, however, can substantially increase the risk of certain types of cancer, such as breast and ovarian cancer. A healthy female individual with a BRCA1 mutation has a lifetime risk of 75% for breast cancer and 44% for ovarian cancer, far higher than the average rates of 12% and 1.3% respectively in the general population.

Access to recommended screening and prevention measures can dramatically decrease this person’s risk of developing cancer, as well as improving their overall survival rate by up to 70%. 

An estimated 1% of the population carries a BRCA gene mutation, yet more than 95% of affected individuals are unaware of it because they have not had access to genetic testing. The current Canadian health system only funds testing for individuals with a personal or family history of cancer. Because of this, most BRCA mutation carriers never get tested, leading to many preventable cancer diagnoses. This current approach also amplifies inequity, with Indigenous and non-European people tending to be under-referred for testing. 

PBT could solve this problem by offering testing to everyone without the need for family history. Recent models based on the Canadian population indicate that PBT could prevent over 3000 breast and ovarian cancers for every 1 million women and people assigned female at birth. This strategy would also be highly cost-effective. Before PBT can be employed, however, it is important to learn if and how the public will accept it.