Interventions to support decision making in people considering germline genetic testing for BRCA 1/2 pathogenic and likely pathogenic variants: A scoping review.

Abstract

Pathogenic and likely pathogenic variants in BRCA1 and BRCA2 (BRCA1/2) are medically actionable and may inform hereditary breast and ovarian cancer (HBOC) treatment and prevention. However, rates of germline genetic testing (GT) in people with and without cancer are suboptimal. Individuals' knowledge, attitudes, and beliefs may influence GT decisions. While genetic counseling (GC) provides decision support, the supply of genetic counselors is insufficient to meet demand. Accordingly, there is a need to explore the evidence on interventions that aim to support BRCA1/2 testing decisions. We conducted a scoping review of PubMed, CINAHL, Web of Science, and PsycINFO using search terms related to HBOC, GT, and decision making. First, we screened records to identify peer-reviewed reports that described interventions to support BRCA1/2 testing decisions. Next, we reviewed full-text reports and excluded studies that lacked statistical comparisons or enrolled previously tested individuals. Finally, we extracted study characteristics and findings into a table. All records and reports were reviewed independently by two authors; decisions were tracked in Rayyan, and discrepancies were resolved through discussion. Of 2116 unique citations, 25 met the eligibility criteria. Articles were published between 1997 and 2021 and described randomized trials and nonrandomized, quasi-experimental studies. Most studies tested technology-based (12/25, 48%) or written (9/25, 36%) interventions. Nearly half (12/25, 48%) of interventions were designed to complement traditional GC. Of the interventions compared to GC, 75% (6/8) increased or had a noninferior effect on knowledge, and 67% (4/6) decreased or had a noninferior effect on decisional conflict. Intervention effects on GT uptake were mixed, which may reflect evolving eligibility criteria for GT. Our findings suggest novel interventions may promote informed GT decision making, but many were developed to complement traditional GC. Trials that assess the effects of decision support interventions in diverse samples and evaluate implementation strategies for efficacious interventions are warranted.