Evaluating Web-Based Direct-to-Consumer Genetic Tests for Cancer Susceptibility

Madison K. Kilbride, PhD; Angela R. Bradbury, MD

Disclosures

JCO Precis Oncol. 2020;4:161-169. 

In This Article

Abstract and Introduction

Abstract

Purpose: Recent years have seen direct-to-consumer (DTC) genetic testing for cancer susceptibility change dramatically. For one, a new model now dominates the market where tests are advertised to consumers but ordered by physicians. For another, many of today's tests are distinguished from earlier DTC offerings for cancer susceptibility by their scope and potential clinical significance. This review provides a comprehensive overview of available DTC genetic tests for cancer susceptibility and identifies aspects of the DTC testing process that could affect consumers' ability to make informed decisions about testing and understand their results.

Methods: First, we provide an overview of each DTC genetic test for cancer susceptibility that includes information about cost; who orders it; whether variants of uncertain significance are returned; availability of genetic counseling; intended users; management of variant reclassifications; whether it is characterized as diagnostic, actionable, and clinically valid; molecular technique used; and Clinical Laboratory Improvement Amendments/College of American Pathologists status. Second, we identify six aspects of the testing process that could affect consumers' ability to make informed decisions about testing and interpret their results: How companies use certain terms (eg, medical grade or clinical grade); how companies use consumers' health information during the ordering process; the extent of genetic counseling provided by companies; companies' procedures for returning results; the role of company-provided ordering physicians; and companies' procedures for communicating variant reclassifications.

Results: On the basis of our review of companies' Web sites, we believe that consumers would benefit from more information about these aspects of testing.

Conclusion: Providing this information would help consumers make informed decisions about whether to use a particular DTC genetic testing service and, should they choose to pursue testing, understand the implications and limitations of their results.

Introduction

Falling costs of genetic testing in combination with growing public interest in personal genomics has driven the expansion of direct-to-consumer (DTC) genetic testing. Today's market encompasses a broad range of offerings, from tests that pair users with wines to tests that reveal serious disease risks.[1] This review focuses on one area of the rapidly expanding DTC market—genetic testing for cancer susceptibility. Within this space, DTC offerings vary considerably in size and scope. The narrowest is a test that screens for three specific mutations in two genes and the broadest is a whole-genome sequencing service that analyzes dozens of genes for mutations that could affect cancer risk.

Traditionally, DTC genetic tests were advertised—and sold—to consumers without involving a health care professional; however, in recent years, a new model of testing has come to dominate the market. In this model, tests are advertised to consumers but ordered by licensed physicians.[2–5] A number of companies even allow consumers to choose between having tests ordered by their own physician or by a company-provided independent physician.

In both the academic literature and the popular media, there is a lack of clarity about which genetic tests count as DTC offerings.[6] This uncertainty, as Hogarth et al[7] explain, stems from ambiguity about the meaning of direct-to-consumer, a term that "has been used variously to refer to both advertising and sale of genetic tests." According to the US National Institutes of Health (NIH), DTC genetic tests "are marketed directly to customers via television, print advertisements, or the Internet, and … can be bought online or in stores."[8] (p163) Under this expansive definition, tests that are advertised to consumers but ordered by licensed physicians—often referred to as the hybrid model—fall within the ambit of DTC genetic testing.[2,5]

Other than the shift toward physician-ordered testing, many of today's tests are distinguished from their predecessors by their scope and potential clinical significance. Previously, in the mid-to-late 2000s, most DTC tests used single-nucleotide variation profiling to assess cancer risk, a process that involves screening a DNA sample for single-nucleotide polymorphisms (SNPs)—single base-pair differences that occur at specific positions in the genome—that may affect cancer risk.[9,10] Single-nucleotide variation profiling, however, tends to have low predictive value for disease risk and limited usefulness in improving health outcomes (ie, clinical utility).

Today's DTC companies have largely moved away from using single-nucleotide variation profiling. Instead, they tend to analyze specific genes for mutations that increase cancer risk. Yet this change has not eliminated uncertainty in cancer susceptibility genetic testing. For many of the genes included in larger tests, a positive result may be associated with uncertain risk estimates and/or unclear medical management strategies.[11,12]

Given how the DTC genetic testing market for cancer susceptibility has changed in recent years, it is essential that health care professionals and researchers working in this space appreciate both the range of tests being offered and the challenges that consumers may face as they navigate this evolving landscape. Part I of this paper provides an overview of available DTC genetic tests for cancer susceptibility as of July 2019. For each test, we discuss cost; who orders it; whether variants of uncertain significance (VUS) are returned; availability of genetic counseling; intended users; whether consumers are recontacted about variant reclassifications; whether the test is characterized by the company as being diagnostic, actionable, and clinically valid; molecular technique used to analyze DNA; and whether the test is Clinical Laboratory Improvement Amendments (CLIA) certified and College of American Pathologists (CAP) accredited.

In Part II, we identify six aspects of the testing process that we believe could affect consumers' ability to make informed decisions about testing and understand the implications—and limitations—of their results.[13] These are: how companies use certain terms (eg, medical grade or clinical grade); how companies use consumers' health information during the ordering process; the extent of genetic counseling provided by companies; companies' procedures for returning results; the role of company-provided ordering physicians; and companies' procedures for communicating variant reclassifications. On the basis of our review of companies' Web sites, we believe that consumers would benefit from more information about these aspects of testing.

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