These findings have "informed our clinical practice, and we now offer mainstream, oncology-led genetic testing to all women diagnosed with incident invasive breast cancer younger than 50 years of age, those with triple-negative breast cancer and/or bilateral breast cancer, those potentially eligible for PARP inhibitors," as well as to men with breast cancer, the authors wrote.

The study was led by Zoulikha Rezoug, MSc, Lady Davis Institute of the Jewish General Hospital, McGill University in Montreal, Quebec, Canada. It was published online on September 3, 2024, in JAMA Network Open.

The COVID-19 pandemic resulted in a 6-month recruitment pause. Adjustments in recruitment criteria, focus on younger patients and those with triple-negative breast cancer could have overestimated prevalence of genetic pathogenic variants among women aged ≥ 70 years.

The study was supported by grants from the Jewish General Hospital Foundation and the Quebec Breast Cancer Foundation, as well as an award from the Fonds de Recherche du Quebec Santé. Two authors reported receiving grants or personal fees from various sources.