Routine germline genetic testing in 3552 unselected NHS breast cancer patients: evidence informing testing criteria and implementation of a 'BRCA-DIRECT' mainstreaming pathway.
Torr B., Mansour L., Fierheller CT., Hamill M., Nolan J., Bell N., Choi S., Allen S., Muralidharan S., MacMahon S., Clinch Y., Valganon-Petrizan M., Harder H., Garrett A., Evans DG., George A., Jenkins V., Fallowfield L., Legood R., Kemp Z., Manchanda R., Turnbull C.
In the North Thames Mainstreaming of Breast Cancer Genetic Testing (NT-MBGT) programme, we piloted testing for breast cancer susceptibility genes (BCSGs) in unselected breast cancer (BC) patients, deploying a clinician-light 'BRCA-DIRECT' mainstreaming pathway; this included home saliva-testing and consent with postal return, written and digital materials, with full access to a Genetic Counsellor Telephone helpline. Across 14 National Health Service (NHS) breast oncology units, we successfully tested 3515 newly-diagnosed BC patients with high levels of patient and breast healthcare professional (HCP) satisfaction and genetics HCPs reporting decreases in service referrals. The pick-up rate of gPVs was 4.7% (166 germline Pathogenic Variants (gPVs) across seven BCSGs). Examining application of current NHS eligibility criteria to the unselected cohort, testing would have been offered to 20.6% of patients with identification of 49.2% of gPVs in high penetrance (HP)-BCSGs (BRCA1/BRCA2/PALB2) and 18.2% of gPVs in intermediate penetrance-BCSGs (CHEK2/ATM/RAD51C/RAD51D). Designing 'Ultra-simple' eligibility criteria suitable for mainstreaming, detection (sensitivity) could be improved to 81.1% and 70.4% respectively, whilst increasing testing to 49.7% of BC cases. Evidence from the NT-MBGT programme demonstrates that expanding BCSG-testing via a clinician-light pathway is acceptable and feasible, without increasing the burden on limited breast and genetics workforce, and has high satisfaction.