Routine germline genetic testing in 3552 unselected NHS breast cancer patients: evidence informing testing criteria and implementation of a 'BRCA-DIRECT' mainstreaming pathway.
Level 4 - case-series / case-control
Prospective uncontrolled implementation cohort study
PubMed 42426004 · doi:10.1038/s41523-026-01000-4
What was done
The North Thames Mainstreaming of Breast Cancer Genetic Testing (NT-MBGT) programme evaluated a clinician-light 'BRCA-DIRECT' pathway across 14 NHS breast oncology units in newly diagnosed, unselected breast cancer patients. The intervention involved postal saliva testing, remote consent using written and digital materials, and a genetic counsellor telephone helpline. The study assessed the pick-up rate across seven breast cancer susceptibility genes (BCSGs: BRCA1, BRCA2, PALB2, CHEK2, ATM, RAD51C, and RAD51D), evaluated provider/patient satisfaction, and modeled the sensitivity of standard NHS criteria versus proposed simplified testing criteria.
What was found
Across 3,515 successfully tested patients, 166 germline pathogenic variants (gPVs) were identified (4.7% pick-up rate). Standard NHS eligibility criteria would have offered testing to 20.6% of the cohort, detecting only 49.2% of high-penetrance BCSG variants (BRCA1/BRCA2/PALB2) and 18.2% of intermediate-penetrance variants (CHEK2/ATM/RAD51C/RAD51D). A newly designed 'ultra-simple' criteria increased testing to 49.7% of patients and improved detection sensitivity to 81.1% for high-penetrance and 70.4% for intermediate-penetrance variants. Patient and oncology healthcare professional satisfaction was high, and genetics teams reported decreases in referral workload.
Why it matters
Standard risk-based genetic testing guidelines miss approximately half of clinically actionable high-penetrance cancer variants in newly diagnosed breast cancer patients. A clinician-light, direct-to-patient saliva testing model substantially increases variant detection while minimizing clinical workforce burden.
Limits
The abstract lacks quantitative data for patient and provider satisfaction metrics. It relies on a single regional NHS network without a randomized control arm comparing workflow efficiencies directly against conventional genetic counseling pathways.
Cited by
- supports Fewer than 5% of women who get breast cancer carry an identified cancer-causing genetic mutation.