Divya Rao , Chloe Wernecke, Lisa Baron, et al. Breast J. 2026 Jan 19:2026:8670441
The Tyrer-Cuzick (TC) or IBIS risk calculator is a widely used tool to estimate the probability of developing breast cancer. The TC is commonly used to guide patients toward further diagnostic imaging, genetic testing, chemoprevention, or risk-reducing surgery. A population of 964 patients with TC was evaluated for 12 PVs and variants of unknown significance (VUS) using lab-agnostic genetic testing. This study found an average TC of 7.71%. A family history of cancer was noted in 78.30% of patients, and a personal history of cancer other than breast occurred in 20.74% of patients. 12.03% of patients were found to have a PV, with an average TC of 8.98%. The most common PVs were CHEK2, BRCA2, BRCA1, and BARD1. Out of those with PVs, 52% had non-BRCA1/2 PVs with an average TC of 5.47%. A total of 102 patients (10.58%) had a VUS, with an average TC of 8.29%. In further statistical analysis, TC were distributed significantly differently among the three groups, with differences observed between the BRCA group and negative group, as well as between BRCA and non-BRCA1/2 PVs group. A higher TC was also associated with BRCA1/BRCA2 variants compared to non-BRCA1/2 PVs. TC scores provide valuable information regarding the lifetime risk of an individual of developing breast cancer. However, the study found they were not associated with prediction of non-BRCA1/2 PVs. When choosing a genetic testing panel for breast cancer genes, TC is not as a reliable predictor on individual patient's family history, NCCN guidelines, or ASBrS guidelines.
15 Apr, 2026