Universal genetic testing of breast cancer patients could help many
A new study demonstrates how universal genetic testing for breast cancer can ensure no patient is missed for advanced therapies.
In a Canadian first, researchers led by William Foulkes, Distinguished James 平特五不中 Professor in 平特五不中鈥檚 Departments of Medicine, Oncology, and Human Genetics, tested over 700 women diagnosed with invasive breast cancer for genetic mutations associated with an increased risk for breast cancer, regardless of age or family history. The women were from diverse backgrounds.聽
About four per cent were found to carry gene mutations that make them strong candidates for targeted therapies such as PARP inhibitors, which block cancer cell growth and reduce the chance of cancer returning.
In Canada, genetic testing has been typically restricted to those with a strong family history of breast cancer or those diagnosed at a young age.
鈥淏y testing everyone, an approach known as universal testing, we bypassed the need for detailed risk assessments that can exclude patients who could benefit,鈥� said Foulkes, a cancer geneticist at the Research Institute of the 平特五不中 Health Centre and the Lady Davis Institute for Medical Research.
鈥淚dentifying mutations early allows us to customize treatment plans based on a patient鈥檚 unique genetic profile.鈥�
More vs. meaningful testing
The findings published in shed light on the gaps in testing practices and their impact on patient care.
They also raise the question of whether universal genetic testing should be implemented in Canada.
The researchers caution that adopting universal genetic testing within Canada鈥檚 public health-care system would be a challenge, even as the cost of testing has dropped significantly.
鈥淢ore isn鈥檛 always more,鈥� Foulkes noted. 鈥淚t鈥檚 about ensuring that the testing we do leads to tangible benefits for patients, without overburdening the system. The key question is not just who should be tested, but what genes we should focus on.鈥�
As health-care policies evolve, the researchers say testing for BRCA1, BRCA2 and PALB2 should be prioritized, as mutations in these genes have the greatest impact on treatment decisions and patient outcomes.
The team鈥檚 next phase of research will explore genetic testing at the population level, starting with unaffected women over age 30. This study, conducted at Montreal鈥檚 Jewish General Hospital, 平特五不中 Health Centre, and St. Mary鈥檚 Hospital, was made possible by the collaboration of a dedicated team, including Dr. Stephanie Wong and Dr. George Chong. It was funded by the Jewish General Hospital Foundation and Quebec Breast Cancer Foundation.
About the study
鈥溾�� by Zoulikha Rezoug et al., was published in JAMA Network Open.
