What is the impact of genetic counselling in women at increased risk of developing hereditary breast cancer? A meta-analytic review.

Meta-analytic methods were used to determine the impact of genetic counselling on women with a family history of breast cancer. Published studies with prospective designs and randomized controlled trials were included in the review, and the psychological outcomes assessed were generalized psychological distress, generalized anxiety, depression, and breast cancer anxiety. Other outcomes investigated were the accuracy of perceived risk of developing breast cancer, breast cancer genetics knowledge and breast cancer screening uptake. A meta-analysis was performed to estimate effect size, where sufficient data were available. A total of 12 studies, most of which measured several outcomes, met at least one of the inclusion criteria. A sufficiently large number of studies were available to assess the magnitude of effects on three outcomes: generalized psychological distress, generalized anxiety and accuracy of perceived risk of developing breast cancer. The quantitative synthesis showed that genetic counselling leads to statistically significant decreases in generalized anxiety, with an average weighted effect sizes of r = - 0.17 (p<0.01). In contrast, the reduction in psychological distress exhibited a trend towards statistical significance only, with r = -0.074 (p = 0.052). The impact of genetic counselling on the accuracy of perceived risk was associated with an effect size of r = 0.56 (p<0.01). Thus in this meta-analysis, we demonstrated the efficacy of genetic counselling in meeting two of its objectives: reducing women's anxiety levels and improving the accuracy of their perceived risk. This review highlighted that most research so far focused on generalized distress and anxiety and accuracy of perceived risk, to the exclusion of other, perhaps equally important, types of outcomes. Future studies are likely to lead to more comprehensive assessments if additional emotional, cognitive and behavioural outcomes are included in the assessment.