How Genetic Testing Impacts Breast Cancer Treatment Decisions

Steven J. Katz, MD, MPH and Reshma Jagsi, MD, DPhil
Published: Tuesday, Nov 10, 2015
University of MichiganSteven J. Katz, MD, MPH
Steven J. Katz, MD, MPH
Director, Socio-Behavioral Program
University of Michigan Comprehensive Cancer Center
Professor, Medicine and Health Management and Policy
University of Michigan
Reshma Jagsi, MD, DPhil
Reshma Jagsi, MD, DPhil
Associate Professor, Radiation Oncology
University of Michigan Medical School
Ann Arbor, MI
Dr. Catherine M. Diefenbach
As genetic testing becomes increasingly available, there will be a growing gap between the wide availability of testing and the relative importance of results to treatment decisions. In the current environment, there’s more promise in precision medicine than practical applications in the exam room. Multigene panel testing is increasingly available, but we don’t fully understand how to best incorporate results into treatment recommendations for patients with breast cancer.

As a result, patients newly diagnosed with breast cancer and their doctors face a conundrum in the exam room: how to efficiently incorporate increasingly complex clinical information into treatment decision making.

The demand is growing for genetic testing. More than a quarter of patients newly diagnosed with breast cancer undergo genetic testing now. That rate has been increasing, and recent studies suggest it could be even higher.

Our study of 1536 breast cancer survivors published this year in the Journal of Clinical Oncology found that 35% of patients had a strong desire for genetic testing.1 Many of the women who reported strong interest were at low risk of having a mutation and might not be typical candidates for a discussion about genetic testing.

Stepwise Approach Needed

But whether results of genetic testing show a mutation or not, what does it mean for physicians recommending treatment options to patients and for patients trying to understand complex treatment options and risk to decide how to treat their cancer? We need to change both the way genetic tests results are reported and, more importantly, how results are incorporated into treatment deliberation for patients newly diagnosed with breast cancer. After diagnosis, patients face a rapid escalation of treatment decisions navigated by different specialists. We need to allow more time for deliberation and a better way to incorporate increasingly more complex genetic and genomic information into the process.

Germline genetic testing often requires discussions with genetic counselors. Patients need a stepwise approach to deliberation and ought not to rush the process. We don’t honor enough the process and time patients need for treatment decision making.

CPM Rates Illustrate Knowledge Gap

This can be seen in the recent uptick in women choosing contralateral prophylactic mastectomy (CPM). A 2014 study in JAMA Surgery found that 70% percent of women who have CPM have no clinical indications, such as a family history of breast or ovarian cancer or a mutation found on genetic testing.2 In fact, many of these women were candidates for breast conservation. It’s striking that so many women are receiving much more extensive surgery than needed to treat their disease.

Women diagnosed with breast cancer are naturally eager to do everything in their power to fight the disease. So many patients confide that they just want to do everything they can to be there for their children. It is up to us, as doctors, to make sure they understand which treatments are really going to do that, and which actions might seem heroic but are actually not expected to improve the outcomes for a typical woman with early-stage breast cancer.

View Conference Coverage
Online CME Activities
TitleExpiration DateCME Credits
Community Practice Connections™: How Do We Leverage PARP Inhibition Strategies in the Contemporary Treatment of Breast Cancer?May 31, 20191.5
Community Practice Connections™: A Better Way to Stop Pain: Paths Toward Responsible Postsurgical Pain Management for Patients With Breast CancerMay 31, 20191.5
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