The efficacy of genetic counseling for familial colorectal cancer: A meta-analysis

Genetic counseling has been proven to be effective for several conditions in relation to outcomes such as risk perception and knowledge. By statistically combining data from individual studies, a meta-analysis can provide a precise estimate of an intervention's overall effect. The aim of this quantitative meta-analysis was to assess the efficacy of genetic counseling for familial colorectal cancer and to explore characteristics that might influence the direction or magnitude of the relationship between the intervention and the outcome. We conducted an electronic search of literature published until March 2024. This identified 3150 articles, 30 of which met the inclusion criteria. Effect size parameters and sample sizes for all variables in each study were included. Results showed that genetic counseling has an overall statistically significant effect size of small magnitude (d = 0.234). Results indicate that genetic counseling is effective for affective (d = 0.162), cognitive (d = 0.298), and behavioral outcomes (d = 0.539); for individuals with a personal and/or family history; whether testing is diagnostic or predictive; and, with the exception of uncertain/uninformative results (4 studies), regardless of the testing results. Also, clinical/research teams that included a genetic counselor generated a significantly larger effect compared to teams without a genetic counselor. Our analysis showed that genetic counseling is effective for familial colorectal cancer. These results should encourage theoretical analyses and empirical studies exploring the process and rationale of genetic counseling from a more programmatic perspective.