Comparison of proactive and usual approaches to offering predictive testing for BRCA1/2 mutations in unaffected relatives.

Abstract

There have been few studies addressing uptake of predictive testing for BRCA1/2, only one comparing a proactive with usual family networking approach to dissemination. We report uptake of predictive genetic testing after directly offering BRCA1 presymptomatic genetic testing to 100 individuals in two generations of 5 large BRCA1 families compared with service testing of 196 families since that time. Uptake was significantly higher in the first generation (group 1), who were directly offered testing, and much higher in females. Seventy-four percent of unaffected women in the first generation proceeded to testing, 42% of men. This decreased to 44% of women in the second generation (group 2) and 9% males (p = 0.0003). Uptake in unaffected individuals in the final group (group 3) with no proactive approach was significantly lower than that in the first group. Overall uptake after 10 years was 56% (95% confidence interval, CI, 50-62%) for group 1 and 36% (95% CI 34.3-37.7%) for 1084 group 3 individuals (p = 0.0003). Among women, uptake was 74% (95% CI 67-81%) in group 1 at 10 years compared with 51.5% (95% CI 49-54%) in 552 group 3 women (p = 0.023). In men, uptake was 42% (95% CI 33-52%) in group 1 and 21.1% (95% CI 18.1-23.1%) among 532 men in group 3 (p = 0.0098). Although these results are not from a randomized trial, they show particularly among men a substantially higher uptake of genetic services with a direct approach. Importance should be given to more proactive approaches to ensure that men in BRCA1/2-positive families receive the appropriate information.