A healthy 37-year-old woman approaches her doctor because she is concerned about her risk of breast cancer. Her mother, maternal aunt, and maternal grandmother had breast cancer, although they were all diagnosed after the age of 50. To help address her concerns, the doctor uses her clinical history and family history to estimate her lifetime breast cancer risk at 18.9%. Professional society guidelines recommend annual mammograms starting at age 40 for average risk women, including those whose lifetime breast cancer risk is less than 20%.1
However, because of the woman’s concern about her family history, the doctor decides to order Myriad myRisk®, a 35-gene hereditary cancer panel. The myRisk test ultimately identifies a pathogenic mutation in the CHEK2 gene. Studies show that a CHEK2 mutation increases a woman’s breast cancer risk to 20-31%.2 This wide range of risk can lead to confusion for patients in understanding their true risk and can cause uncertainty for patients and providers in determining what the most appropriate management may be.
However, the woman’s myRisk panel also evaluates 86 genetic markers that have been associated with breast cancer. This additional analysis, called riskScore®, allows for a more individualized breast cancer risk estimate of 30.1%. The woman and her doctor now have a better understanding of her lifetime breast cancer risk and can plan their next medical management steps accordingly.
- NCCN Clinical Practice Guidelines in Oncology. Breast Cancer Screening and Diagnosis (Version 1.2019). https://www.nccn.org/professionals/physician_gls/pdf/breast-screening.pdf. Accessed August 20, 2020.
- Kurian A, et al. Breast and Ovarian Cancer Penetrance Estimates Derived from Germline Multiple-Gene Sequencing Results in Women. JCO Precision Oncol. 2017.