KEY TAKEAWAYS
- The study aimed to evaluate the prevalence of germline pathogenic variants in breast cancer susceptibility genes among newly diagnosed women.
- Researchers found 7.3% GPV prevalence, with 5.3% B1B2P2 positive; one-third were eligible for PARP inhibitors.
Between 5% and 10% of breast cancer are hereditary, linked to inherited genetic mutations. Traditional genetic testing methods often miss a portion of these cases.
Zoulikha Rezoug and the team sought to evaluate the prevalence of germline pathogenic variants (GPVs) in breast cancer susceptibility genes (BCSGs) in a diverse group of women newly diagnosed with invasive breast cancer.
The study was conducted at 3 Montreal hospitals from September 2019 to April 2022. All women with a new diagnosis of invasive breast cancer within 6 months were offered genetic counselling and testing. The testing included a primary panel of BRCA1, BRCA2, and PALB2 genes (B1B2P2) and an optional secondary panel of 14 additional BCSGs.
Of the 805 eligible patients, 729 (90.6%) consented to testing. The study found GPVs in 53 patients (7.3%), with 39 patients (5.3%) testing positive for B1B2P2 and 15 (2.1%) for other BCSGs. Notably, 33.3% of B1B2P2-positive patients were eligible for poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors, a targeted therapy for hereditary cancers.
The study revealed a significant prevalence of GPVs in a diverse cohort of women with newly diagnosed invasive breast cancer. The findings suggested that expanding genetic testing criteria could be beneficial in identifying patients who may benefit from targeted therapies like PARP inhibitors, ultimately improving treatment outcomes.
This work was funded by a grant from the Jewish General Hospital Foundation and the Quebec Breast Cancer Foundation to Dr Foulkes and award 309854 from the Fonds de Recherche du Quebec Santé to Dr Wong.
Source: https://pubmed.ncbi.nlm.nih.gov/39226054/
Rezoug Z, Totten SP, Szlachtycz D, et al. (2024). “Universal Genetic Testing for Newly Diagnosed Invasive Breast Cancer.” JAMA Netw Open. 2024;7(9):e2431427. Published 2024 Sep 3. doi:10.1001/jamanetworkopen.2024.31427
