Cancer risk distress is not different when genetic testing and delivery of results is offered without mandatory posttest counseling compared with mandatory pre- and posttest counseling in women at risk for hereditary breast and ovarian cancer.
In the 4-arm noninferiority clinical trial known as MAGENTA (Making Genetic Testing Accessible), 19% of subjects overall had very high distress at 3 months of follow-up after genetic testing (P = .0083), a rate that was noninferior (P <.025) in groups randomized to counseling available at request compared with those randomized to mandatory pre- and posttest counseling, reported Elizabeth M. Swisher, MD, Director, Gynecologic Oncology, University of Washington, and Co-Leader, Breast and Ovarian Cancer Research Program, Seattle Cancer Care Alliance, WA, at the annual American Society of Clinical Oncology 2020 virtual meeting.
“These results support use of a genetic testing paradigm providing individualized posttest genetic counseling only for patients with positive results and for those patients who request additional counseling,” said Dr Swisher.
MAGENTA evaluated electronic genetic education and results delivery alone or combined with pretest counseling only, or posttest only telephone genetic counseling, comparing them with mandatory pre- and posttest counseling (control arm) in women at risk for hereditary breast and ovarian cancer.
“The current paradigm for genetic testing includes identifying a patient based on personal or family risk factors, having them come in for genetic counseling, provide consent and sample, and then come in for a second [follow-up] appointment for posttest results and counseling,” said Dr Swisher. “This paradigm leads to a number of barriers, including inadequate recognition and referral of eligible patients by physicians, the lack of availability of genetic counselors, the lack of knowledge about the benefits of genetic information for patients and providers, inconvenience of requiring 2 visits, and cost.”
The primary end points of MAGENTA were to determine whether genetic testing can be delivered in women’s homes and how much genetic counseling is optimal.
Women were recruited online and randomized to 1 of 4 arms: no pre- or posttest education or counseling; telephone counseling only upon release of the genetic testing results; pretest electronic education and posttest counseling for all via telephone (control arm); and pretest education but no posttest counseling. In all arms, patients watched an online educational video. All participants had access to a counselor at any time if desired. All who had a pathogenic mutation received posttest counseling regardless of which arm they were in.
Women were eligible if they were aged ≥30, had no personal history of ovarian cancer and had ≥1 ovaries, and had no previous genetic counseling or testing. Some 3833 subjects who completed the baseline questionnaire were randomized.
There were 2 cohorts recruited: 3111 patients in the family history cohort had a family history of breast or ovarian cancer or personal history of breast cancer, and 711 patients in the cascade cohort had a blood relative with a breast or ovarian cancer gene mutation.
Sequencing was performed for a standard susceptibility panel for 19 breast and ovarian cancer genes. If no pathogenic mutations were identified, results were released either electronically or via a telephone counselor.
Overall, 174 patients (6.1%) had pathogenic mutations in one of the genes surveyed. The positivity rate was 5.1% in the family history cohort and 12.1% in the cascade cohort. In the family history cohort, the most commonly involved genes were CHEK2 and ATM, followed by BRIP1, BRCA2, and BRCA1. In the cascade cohort, the most commonly mutated genes were BRCA2 and BRCA1, followed by CHEK2, BRIP1, ATM, and PMS2.
Distress 3 months following receipt of the results did not differ significantly across the arms in either cohort. In addition, the change in distress was not significantly different between arms. Levels of secondary end points (anxiety, depression, and decisional regret) were also not significantly different across the arms.
“What I’ve learned is that this type of online delivery of services can be recommended by physicians, and it really can make a difference in areas of the country that don’t have accessibility to genetics programs,” commented Karen H. Lu, MD, Professor and Chair, Gynecologic Oncology and Reproductive Medicine, MD Anderson Cancer Center, Houston, TX.