Uptake of BRCA1/BRCA2 predictive genetic testing in an Irish population is low: a missed opportunity

Ir J Med Sci. 2022 Oct 19. doi: 10.1007/s11845-022-03176-7. Online ahead of print.

Abstract

Introduction: Predictive testing for BRCA1 or BRCA2 allows at-risk individuals to engage with appropriate screening and treatment services if a pathogenic mutation is identified. Previous studies have shown uptake of predictive testing to most commonly range between 20% and 40% (Table 2). This represents a missed cancer prevention opportunity. Possible explanations for this low uptake include lack of disclosure of at-risk status to relatives, lack of awareness of cancer genetics services, or patient preference. The goal of the current study was to investigate the uptake of BRCA1 or BRCA2 predictive testing in an Irish population.

Methods: We performed a multicentre, retrospective analysis of 63 pedigrees from two Irish tertiary referral hospitals over a five-year period (2012-2017). Family pedigrees were reviewed to identify at-risk family members eligible for predictive BRCA1 or BRCA2 mutation testing as per international guidelines, and testing rates were determined.

Results: A total of 1048 eligible individuals were identified, 318 (30.4%) proceeded to BRCA1 or BRCA2 germline testing including [215 (37.5%) females and 99 males (21.5%)]. Women were significantly more likely to test than men (T = 3.7, p < .0002). Uptake of testing was significant higher amongst first-degree relatives 45% (150/323) compared to 20% (50/258) amongst second degree relatives, and 10 % (33/317) amongst more distant relatives (F = 25.32, p < 0.00001).

Conclusions: Uptake of BRCA1 OR BRCA2 mutation testing in Ireland is suboptimal, particularly amongst Irish males and distant relatives. Further research is needed to identify strategies which may improve uptake within current legal and ethical frameworks.

Keywords: Breast cancer; Cancer genetics; Ovarian cancer; Predictive testing.