Researchers at the University of Cambridge have criticised a recent study which called for extended genetic testing for all breast cancer patients.
In a recent issue of Journal of Clinical Oncology, Beitsch et al argue for expanded panel testing in all patients with a diagnosis of breast cancer (BCa). Their argument rested on the finding that of patients who met US guideline criteria for testing, 9.39 per cent had a pathogenic/likely pathogenic variant; 7.9 per cent of patients who did not meet guidelines also had one of these variants.
However, in a letter published in the same journal, Dr Marc Tischkowitz from the Department of Medical Genetics at the University of Cambridge and Dr Amy Taylor from Cambridge University Hospitals claim the study is flawed.
Drs Tischkowitz and Taylor say the study included many variants that have no definite proven association with an increased risk of BCa. They re-analysed the data, focusing only on variants with definitive evidence on risk. This brought the proportion of patients with a pathogenic/likely pathogenic variant down to 6.47 per cent for those who met guidelines and 3.75 per cent for those who did not.
Furthermore, they point out that a third of the 27 study authors are employees of or receive honoraria, research funding or indirect support from diagnostic laboratories that are heavily involved in marketing gene panels, which could result in a significant conflict of interest when interpreting of the results of the study.
