Examining the uptake of predictive BRCA testing in the UK; findings and implications

Predictive BRCA testing is offered to asymptomatic individuals to predict future risk where a variant has been identified in a relative. It is uncertain whether all eligible relatives access testing, and whether this is related to health care inequalities. Our aim was to analyse trends and inequalities in uptake of testing, and identify predictors of testing and time-to-receipt of testing. A database from April 2010 to March 2017 was collated. Multivariate analysis explored individual associations with testing. Predictor variables included gender, BRCA test type, cancer history, Index of Multiple Deprivation (IMD) and education status. To evaluate factors associated with time-to-testing, a Cox proportional-hazards (CP) model was used. Of 779 tests undertaken, 336 (43.1%) were identified with a BRCA variant. A total of 537 (68.9%) were female and in 83.4% (387/464) of probands, predictive testing was received by relatives. Analysis identified inequalities since decreased testing was found when the proband was unaffected by cancer (OR 0.14, 95% CI 0.06-0.33). Median time-to-testing was 390 days (range, 0-7090 days) and the CP model also identified inequalities in the hazard ratio (HR) for testing for people aged >40 was higher than for aged <40 (HR 1.41, 95% CI 1.20-1.67) and BRCA2 testing was higher than for BRCA1 testing (HR 1.39, 95% CI 1.18-1.64). Reduced testing was found when probands were unaffected by cancer and time-to-testing was found to vary by age and BRCA1/2 test. Given limited study sample size, further research is recommended to examine inequalities in predictive BRCA testing.