Systematic evidence review and meta-analysis of outcomes associated with cancer genetic counseling

Abstract

Purpose: Genetic counseling (GC) is standard of care in genetic cancer risk assessment (GCRA). A rigorous assessment of the data reported from published studies is crucial to ensure the evidence-based implementation of GC.

Methods: We conducted a systematic review and meta-analysis of 17 patient-reported and health-services-related outcomes associated with pre- and post-test GC in GCRA in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

Results: Twenty-five of 5393 screened articles met inclusion criteria. No articles reporting post-test GC outcomes met inclusion criteria. For patient-reported outcomes, pre-test GC significantly decreased worry, increased knowledge, and decreased perceived risk but did not significantly affect patient anxiety, depression, decisional conflict, satisfaction, or intent to pursue genetic testing. For health-services outcomes, pre-test GC increased correct genetic test ordering, reduced inappropriate services, increased spousal support for genetic testing, and expedited care delivery but did not consistently improve cancer prevention behaviors nor lead to accurate risk assessment. The GRADE certainty in the evidence was very low or low. No included studies elucidated GC effect on mortality, cascade testing, cost-effectiveness, care coordination, shared decision making, or patient time burden.

Conclusion: The true impact of GC on relevant outcomes is not known low quality or absent evidence. Although a meta-analysis found that pre-test GC had beneficial effects on knowledge, worry, and risk perception, the certainty of this evidence was low according to GRADE methodology. Further studies are needed to support the evidence-based application of GC in GCRA.

Keywords: Cancer genetics; GRADE; Genetic counseling; Health services; Outcomes; PRISMA.