Purpose: Sequence-based cancer susceptibility testing results are described as negative, deleterious mutation or variant of uncertain significance. We studied the impact of different types of test results on clinical decision making.
Methods: Practicing physicians from five specialties in Texas completed an online case-based survey (n = 225). Respondents were asked to make genetic testing and management recommendations for healthy at-risk relatives of patients with cancer.
Results: When the patient carried a deleterious BRCA1 mutation or variant of uncertain significance, 98% and 82% of physicians, respectively, recommended testing of at-risk relatives (P < 0.0001). In both situations, comprehensive BRCA1/2 analysis was selected most with a corresponding 9-fold increase in unnecessary genetic testing costs. There was no difference in physicians with (n = 81) or without (n = 144) prior BRCA1/2 testing experience (P = 0.3869). Cancer risk management recommendations were most intense for the relative with a deleterious mutation compared with variant of uncertain significance, negative, or no testing with 63%, 13%, 5%, and 2%, respectively, recommending oophorectomy (P < 0.0001).
Conclusions: Independent of experience, or specialty, physicians chose more comprehensive testing for healthy relatives than current guidelines recommend. In contrast, management decisions demonstrated the uncertainty associated with a variant of uncertain significance. Utilization of genetic professionals and education of physicians on family-centered genetic testing may improve efficacy and substantially reduce costs.