Uptake of pre-symptomatic testing for BRCA1 and BRCA2 is age, gender, offspring and time-dependent

J Med Genet. 2020 Apr 30:jmedgenet-2019-106544. doi: 10.1136/jmedgenet-2019-106544. Online ahead of print.

Abstract

Background: Genetic testing for BRCA1 and BRCA2 pathogenic variants (PVs) has been available in North West England since 1995. We assessed uptake of pre-symptomatic testing in 1564 families with PVs over a 24.5year follow-up (FU) period.

Methods: First-degree relatives (FDRs) in families with BRCA1 or BRCA2 PVs were eligible from date of index family report if unaffected by a relevant cancer and alive at report date. FDRs were censored as not having undergone a pre-symptomatic test at diagnosis of a relevant cancer, date of death, age 93 or 30/03/2019. Time to uptake of pre-symptomatic testing was assessed by Kaplan-Meier curves, by gender and children.

Results: 2554 male and 3115 female FDRs were eligible. Overall uptake was 775 (30.3%) in men and 1935 (62.1%) in women. This increased at 15 years to 33.6% and 67.9%, and continued to rise until 24 years (p<0.001). For women, the 29-year to 39-year age group had the highest uptake at 10 years FU (72.5%; p<0.01), whereas the 50-year to 59-year age group was highest in men (37.2%; p<0.01). Women <18 years at the time of familial variant identification had lower initial uptake, but this rose to >80% by 15 years. Uptake was higher in parous women (p<0.001) and in men with daughters (p<0.0001).

Conclusion: Uptake of BRCA1/2 pre-symptomatic testing is age, gender and time-dependent, and higher in women with children and men with daughters.

Keywords: BRCA 1/2; genetic register; pre-symptomatic testing.