Purpose: Multigene panels (MGPs) are increasingly being used despite questions regarding their clinical utility and no standard approach to genetic counseling. How frequently genetic providers use MGP testing and how patient-reported outcomes (PROs) differ from targeted testing (eg, BRCA1/2 only) are unknown.
Methods: We evaluated use of MGP testing and PROs in participants undergoing cancer genetic testing in the multicenter Communication of Genetic Test Results by Telephone study (ClinicalTrials.gov identifier: ), a randomized study of telephone versus in-person disclosure of genetic test results. PROs included genetic knowledge, general and state anxiety, depression, cancer-specific distress, uncertainty, and satisfaction. Genetic providers offered targeted or MGP testing based on clinical assessment.
Results: Since the inclusion of MGP testing in 2014, 395 patients (66%) were offered MGP testing. MGP testing increased over time from 57% in 2014 to 66% in 2015 (P = .02) and varied by site (46% to 78%; P < .01). Being offered MGP testing was significantly associated with not having Ashkenazi Jewish ancestry, having a history of cancer, not having a mutation in the family, not having made a treatment decision, and study site. After demographic adjustment, patients offered MGP testing had lower general anxiety (P = .04), state anxiety (P = .03), depression (P = .04), and uncertainty (P = .05) pre-disclosure compared with patients offered targeted testing. State anxiety (P = .05) and cancer-specific distress (P = .05) were lower at disclosure in the MGP group. There was a greater increase in change in uncertainty (P = .04) among patients who underwent MGP testing.
Conclusion: MGP testing was more frequently offered to patients with lower anxiety, depression, and uncertainty and was associated with favorable outcomes, with the exception of a greater increase in uncertainty compared with patients who had targeted testing. Addressing uncertainty may be important as MGP testing is increasingly adopted.