The Need to Improve the Clinical Utility of Direct-to-Consumer Genetic Tests: Either Too Narrow or Too Broad

Direct-to-Consumer Genetic Tests and Canadian Genetic Counselors: A Pilot Exploration of Professional Roles in Response to Novel Biotechnologies

The role of genetic counselors is evolving in response to health-related direct-to-consumer genetic tests (DTC-GT). While there is consensus in the literature that pre- and post-DTC-GT genetic counseling would benefit consumers, genetic counselors have reservations about DTC-GTs, and there is a paucity of research on providing DTC-GT counseling. This pilot quantitative survey is the first study to examine Canadian genetic counselors' views on DTC-GTs and how this disruptive biotechnology affects their role, and consumer informed consent and privacy. Canadian genetic counselors are cognizant of the harm to informed consent and privacy associated with DTC-GT, but are hesitant to engage directly, wary of misusing clinical time and resources. However, counselors are open to producing educational materials on DTC-GTs and collaborating with other stakeholders and the DTC-GT industry to support consumers. In this study, practical considerations for DTC-GT counseling sessions are discussed, including the unique needs of DTC-GT patients and the challenges posed by DTC-GTs to the genetic counseling duty to inform. This research benefits genetic counselors and physicians by examining how best to utilize genetic counselors' skills in the DTC-GT context, to minimize burdens on the healthcare system and support DTC-GT consumers.

Time Trends in Receipt of Germline Genetic Testing and Results for Women Diagnosed With Breast Cancer or Ovarian Cancer, 2012-2019

PURPOSE

Genetic testing is important for breast and ovarian cancer risk reduction and treatment, yet little is known about its evolving use.

METHODS

SEER records of women of age ≥ 20 years diagnosed with breast or ovarian cancer from 2013 to 2017 in California or Georgia were linked to the results of clinical germline testing through 2019. We measured testing trends, rates of variants of uncertain significance (VUS), and pathogenic variants (PVs).

RESULTS

One quarter (25.2%) of 187,535 patients with breast cancer and one third (34.3%) of 14,689 patients with ovarian cancer were tested; annually, testing increased by 2%, whereas the number of genes tested increased by 28%. The prevalence of test results by gene category for breast cancer cases in 2017 were BRCA1/2, PVs 5.2%, and VUS 0.8%; breast cancer-associated genes or ovarian cancer-associated genes (ATM, BARD1, BRIP1, CDH1, CHEK2, EPCAM, MLH1, MSH2, MSH6, NBN, NF1, PALB2, PMS2, PTEN, RAD51C, RAD51D, STK11, and TP53), PVs 3.7%, and VUS 12.0%; other actionable genes (APC, BMPR1A, MEN1, MUTYH, NF2, RB1, RET, SDHAF2, SDHB, SDHC, SDHD, SMAD4, TSC1, TSC2, and VHL) PVs 0.6%, and VUS 0.5%; and other genes, PVs 0.3%, and VUS 2.6%. For ovarian cancer cases in 2017, the prevalence of test results were BRCA1/2, PVs 11.0%, and VUS 0.9%; breast or ovarian genes, PVs 4.0%, and VUS 12.6%; other actionable genes, PVs 0.7%, and VUS 0.4%; and other genes, PVs 0.3%, and VUS 0.6%. VUS rates doubled over time (2013 diagnoses: 11.2%; 2017 diagnoses: 26.8%), particularly for racial or ethnic minorities (47.8% Asian and 46.0% Black, v 24.6% non-Hispanic White patients; P < .001).

CONCLUSION

A testing gap persists for patients with ovarian cancer (34.3% tested v nearly all recommended), whereas adding more genes widened a racial or ethnic gap in VUS results. Most PVs were in 20 breast cancer-associated genes or ovarian cancer-associated genes; testing other genes yielded mostly VUS. Quality improvement should focus on testing indicated patients rather than adding more genes.

Direct-to-Consumer Genetic Testing: Value and Risk

Although the explosive growth of direct-to-consumer (DTC) genetic testing has moderated, a substantial number of patients are choosing to undergo genetic testing outside the purview of their regular healthcare providers. Further, many industry leaders have been expanding reports to cover many more genes, as well as partnering with employers and others to expand access. This review addresses continuing concerns about DTC genetic testing quality, psychosocial impact, integration with medical practice, effects on the healthcare system, and privacy, as well as emerging concerns about third-party interpretation services and non-health-related uses such as investigative genetic genealogy. It concludes with an examination of two possible futures for DTC genetic testing: merger with traditional modes of healthcare delivery or continuation as a parallel system for patient-driven generation of health-relevant information. Each possibility is associated with distinctive questions related to value and risk.