ICARE Social Media Post December 2020

Genetic Testing in Women with Breast Cancer

Approximately 4,000 women with breast cancer were tested for mutations in nine breast cancer genes – 6.2% had mutations in at least one of the nine genes, and 2.7% had mutations in either 𝘽𝙍𝘾𝘼1 or 𝘽𝙍𝘾𝘼2. Comparisons between women who did versus did not meet National Comprehensive Cancer Network (NCCN) guidelines for testing showed that:
 
­- Sensitivity of NCCN criteria was:
70% for any of the nine genes
87% for 𝘽𝙍𝘾𝘼1/2
 
– Sensitivity when including all women diagnosed with breast cancer at or before age 65 was:
>90% for any of the nine genes
>98% for 𝘽𝙍𝘾𝘼1/2
­
– Specificity of NCCN criteria was 53%, which dropped to 22% when including all women diagnosed with breast cancer at or before age 65.
 
These expanded criteria required testing 31% more women compared to NCCN criteria, with 21% remaining untested. This study provides us with additional information to direct the refinement of guidelines, given that we need to balance yield of testing with the added resources needed to expand testing criteria.
 
Check out the original article at: https://ascopubs.org/doi/full/10.1200/JCO.19.02190