Clinician-Reported Impact of Germline Multigene Panel Testing on Cancer Risk Management Recommendations

Background: With increased adoption of multi-gene panel testing (MGPT) for hereditary cancer, management guidelines now include a wider range of predisposition genes. Yet little is known about whether MGPT results prompt changes to clinicians' risk management recommendations and whether those recommendations adhere to guidelines. Methods: We assessed cancer risk management recommendations made by clinicians ordering MGPT for hereditary cancer at a diagnostic laboratory using an internet-based survey. We received paired pre- and posttest responses for 2172 patients (response rate- = 14.3%). Unpaired posttest responses were received in 168 additional patients with positive results. All tests were 2-sided. Results: Clinicians reported a change in risk management recommendations for 76.6% of patients who tested positive for a pathogenic or likely pathogenic variant, with changes to surveillance being most common (71.1%), followed by surgical (33.6%), chemoprevention (15.1%), and clinical trial (9.4%) recommendations. Clinicians recommended risk-reducing interventions more often for patients with pathogenic variants in high-risk than moderate-risk genes (P < .001), whereas surveillance recommendations were similar for high-risk and moderate-risk genes. Guideline adherence was high for surveillance (86.3%) and surgical (79.6%) recommendations. Changes to risk management recommendations occurred in 8.8% and 7.6% of patients with uncertain and negative results, respectively. Conclusions: Clinicians report frequent changes to cancer risk management recommendations based on positive results in both high-risk and moderate-risk genes. Reported introduction of interventions in patients with inconclusive and negative results is rare and adherence to practice guidelines is high in patients with positive results, suggesting a low probability of harm resulting from MGPT.