Pathogenic Variants Lead to Better Attitudes, Engagement in Genetic Testing

“These findings suggest that patient engagement with family about genetic testing and patient report of their preventive behaviors match the clinical relevance of their test results,” according to the study authors.

Women with pathogenic variants on germline testing after a diagnosis of cancer were more amenable to testing relatives and having greater engagement with clinicians about the results compared with those who had variants of uncertain significance on tests, according to a presentation from the 2024 American Society of Clinical Oncology (ASCO) Quality Care Symposium.

The study surveyed patients who were selected from the Georgia California Genetic Linkage Initiative, focusing on all patients diagnosed with cancer between 2013 and 2019 who had a germline genetic test in those 2 states. A total of 1480 patients were surveyed who had breast, ovarian, or uterine cancers between 2018 to 2019 and had reported a pathogenic variant approximately 4 years after their diagnosis.

Additionally, there was a comparable population of 1250 patients surveyed who had been diagnosed in the same period but had only received a variant of uncertain significance results. Investigators expected the response rate from the cohorts to be 55% (n = 1500).

“These findings suggest that patient engagement with family about genetic testing and patient report of their preventive behaviors match the clinical relevance of their test results,” Steven J. Katz, MD, MPH, professor of Health Management and Policy, and professor in the Department of Internal Medicine of the University of Michigan School of Public Health, and co-authors wrote in the poster.

This study was developed because cascade testing for those with hereditary cancer relies on patients to be responsible and engage with their relatives about test results. Investigators were also concerned that patient engagement with clinicians and relatives would not match with their test results, leading to no hereditary testing and concerns over variants of uncertain significance.

The survey had patients report on their attitudes about cascade family testing, engagement with genetic counselors and relatives about results, and their preventative behaviors after diagnosis.

For patients with breast cancer, prevention and high-risk screening by pathogenic variants were identified. For those with BRCA1/2 or PALB2 or high-risk pathogenic variants, about 80% had a bilateral mastectomy, about 10% had screening only, and about 10% had neither. For those with CHEK2 and ATM mutations or lower-risk pathogenic variants, about 55% had a bilateral mastectomy, about 20% had screening only, and about 25% had neither.

Of those with other pathogenic variants, about 50% had a bilateral mastectomy, about 20% had screening only, and about 30% had neither. For those with variants of uncertain significance, about 40% had a bilateral mastectomy, about 35% had screening only, and about 25% had neither.

Patient attitudes about communication with relatives and engagement with genetic counselors were also assessed between those with pathogenic variants (n = 837) and those with variants of uncertain significance only (n = 256). Between both groups, response rates for each statement were: I wanted my family members to get genetic testing (81% vs 44%), my genetic test results are useful to my family members (88% vs 62%), and genetic testing can help prevent cancer in my family members (75% vs 56%).

When questions were asked specifically about a genetic counselor, response rates for those with pathogenic variants or variants of uncertain significance were as follows: a genetic counselor encouraged you to talk about your test results with your relatives (72% vs 56%), gave you advice on how to talk to relatives about your results (57% vs 45%), and talked directly with your relatives about genetic testing (38% vs 25%).

Additionally, the proportion of eligible relatives for whom patients shared test results were also assessed. For first-degree relatives, those with pathogenic variants shared their results about 85% of the time vs about 65% for those with variants of uncertain significance. For second-degree relatives, results were shared about 45% of the time vs about 25%.

“Compared [with] women with [variants of uncertain significance]-only test results, women with [pathogenic variants] on germline genetic testing after diagnosis of cancer had more positive attitudes about the utility of testing relatives, greater engagement with clinicians and family members about test results, and better match with cancer prevention behaviors,” the study authors concluded.

Reference

Katz SJ, Wallner LP, Hawley ST, Abrahmse P, Hodan R, Kurian AW. Attitudes and engagement about cascade genetic testing among women diagnosed with cancer. JCO Oncol Pract. 2024;20(10):313. doi:10.1200/OP.2024.20.10_suppl.313