Abstract
BACKGROUND: Patients are commonly referred to cancer genetics services when all affected family members are deceased. This makes genetic testing and risk assessment more difficult, reducing the benefit from screening and prophylactic treatment. METHODS: Observational, retrospective, cohort study of 508 randomly selected patients referred to a regional cancer genetics unit, using review of case notes to explore whether a simple clinical "3, 2, 1" family history rule could have been used to improve timely and appropriate referrals for genetic assessment. The 3, 2, 1 criteria are: three affected relatives with the same/associated cancers, across two generations, with at least one person affected age <50 years. RESULTS: Most (71% [362]) genetic risk assessment referrals were in unaffected individuals and 22% (80) of these were referred after all affected family members had died, including 24% (19) who lost their last remaining affected relative in the previous year. Most (59% [301]) referrals met all 3, 2, 1 criteria, and 67% of these could have been made earlier in clinical practice. A further 23% (115) met two of the three criteria. CONCLUSION: Using a simple "3, 2, 1" family rule in cancer care and particularly in palliative care could enable earlier cancer genetic risk assessment for unaffected relatives, improving the potential to benefit from targeted screening and intervention.