Two studies presented at the recent annual meeting of the American Society of Clinical Oncology (ASCO) demonstrated the ability of the RiskScore test from Myriad Genetics, Salt Lake City, to provide personalized breast cancer risk information that enables patients and physicians to make better-informed clinical treatment decisions.
RiskScore is a clinically validated personalized medicine tool that uses clinical risk factors and genetic markers to predict a woman’s lifetime risk of developing breast cancer. It has been validated to predict breast cancer risk in women of European descent. The test incorporates data from more than 80 single-nucleotide polymorphisms identified through 20 years of genomewide association studies in breast cancer. The data are combined with a family and personal history algorithm to provide every patient with an individualized breast cancer risk score.
“We are excited to further demonstrate Myriad’s commitment to providing the best possible risk assessment tools to patients through innovation,” says Nicole Lambert, president of Myriad oncology, Myriad women’s health, and Myriad international. “The validation data we are presenting at ASCO this year will support a broader launch of RiskScore to even more women in the coming year, with more personalized information and the unique ability to modify carrier risk through a clinically validated tool.”
Summaries of the studies are as follows.
Comprehensive Breast Cancer Risk Assessment for CHEK2 Carriers.1 In this study, 358,471 women with hereditary cancer risk who were tested with a multigene panel were assessed to find 4,331 women who were carriers of deleterious CHEK2 mutations. These patients were used to develop a mathematical model to assess risk status, using family history information and Myriad’s RiskScore test. The model was then validated in an independent cohort of 459 women.
Among CHEK2 pathogenic variant carriers, significant correlations were detected of CHEK2 status with family history (p = 4.1 × 10–17), and of polygenic risk scores with family history (p= 1.7 × 10–5). Among the patients in the validation cohort, 24.0% of CHEK2 carriers were categorized as low risk (CHEK2 carriers, risk estimation incorporating a polygenic risk score and Tyrer-Cuzick model variables generated breast cancer risks greater than 50%, consistent with genes recognized as highly penetrant.
Performance of the IBIS/Tyrer-Cuzick Model by Race/Ethnicity.2 In this study, 91,893 women of differing racial identities with no personal history of breast cancer were followed for a median of 18.9 years to assess incidence of breast cancer. During that time, 6,836 new cases of breast cancer were diagnosed among the women. The Tyrer-Cuzick model was used to assess risk of breast cancer and then actual cases of breast cancer were compared to expected cases based upon the Tyrer-Cuzick risk assessment. The study found that the Tyrer-Cuzick model was an accurate predictor of breast cancer risk among various ethnicities except for Hispanic women, for whom it overestimated breast cancer risk (ratio of observed versus expected cases overall was 0.95).
For more information, visit Myriad Genetics.
1. Gallagher S, Hughes E, Kurian AW, et al. Comprehensive breast cancer (BC) risk assessment for CHEK2 carriers incorporating a polygenic risk score (PRS) and the Tyrer-Cuzick (TC) model [abstract, online]. J Clin Oncol. 2020;38(15):1504; doi: 10.1200/jco.2020.38.15_suppl.1504.
2. Kurian AW, Hughes E, Bernhisel R, et al. Performance of the IBIS/Tyrer-Cuzick (TC) model by race/ethnicity in the Women’s Health Initiative [abstract, online]. J Clin Oncol. 2020;38(15):1503; doi: 10.1200/jco.2020.38.15_suppl.1503.
Featured image: Precision breast cancer risk categorization among CHEK2 carriers. Graph courtesy Myriad Genetics.