Patients younger than 41 years with HER2+ breast cancer and no family history have low risk of carrying high risk genes, according to data from a recent study.1
The research team, based at Southampton General Hospital, UK, selected patients from a cohort study that had been diagnosed at age 40 or younger with HER2 amplified breast cancer. The genetic test utilized was either research-based using a panel of 17 breast cancer susceptibility genes (which included BRCA1 and BRCA 2) or clinical testing for BRCA1 and BRCA2. Both groups were also tested for TP53 as well.
Out of 591 patients included in the study, 133 patients had clinical testing and 263 patients had panel testing. BRCA mutations discovered in 396 patients equaled 8 BRCA2 and 6 BRCA1 mutations. Three percent (9) of the 304 patients tested for TP53 indicated a deleterious mutation. Eleven percent of of 101 patients that met clinical criteria (≥10% probability) were determined to have pathogenic BRCA mutations. For the <10% group, 4 patients (1%) had a BRCA mutation indicated. Seven TP53 mutations were discovered in the 59 patients that had TP53 tests and met the 10% threshold.
The investigators recommend both BRCA and TP53 genetic testing for individuals with a strong family history.
1. Eccles DM, Li N, Handwerker R, et al. Genetic testing in a cohort of young patients with HER2 amplified breast cancer [published online ahead of print December 17, 2015]. Ann Oncol. doi:10.1093/annonc/mdv592.