Study: Patient experiences with genetic testing

IN DEPTH REVIEW OF RESEARCH

Study background:

Genetic testing is becoming increasingly available and more affordable. In the past few years, panel tests identifying mutations in multiple genes that increase a person’s risk for cancer have become widely available. Twenty years ago, genetic testing only identified whether an individual’s DNA had changes in the BRCA genes. Now, panel testing simultaneously searches for mutations in more than 20 different genes that are associated with increased cancer risk.  This study looks at breast cancer patients’ experiences with genetic testing in this new environment.

Allison Kurian and colleagues from Stanford University and other institutions published work in the Journal of the American Medical Association in February 2017; they collected data on breast cancer patient preferences and experiences with genetic testing.

Researchers of this study wanted to know:

What are breast cancer patients’ experiences with genetic counseling and testing?   

Population(s) looked at in the study:

The study included 2,529 women between the ages of 20 and 79 who were diagnosed with stages 0-II breast cancer between July 2013 and September 2014. These women were identified from the Surveillance Epidemiology and End Results (SEER) data registries from Georgia and Los Angeles County.

Women in the study were mailed surveys that questioned them about:

• how much they wanted genetic testing
• whether they talked about genetic testing with any “doctor or other health professional”
• whether they had a session with a genetic counseling expert
• whether they had genetic testing

Women from this population were categorized as high risk for carrying a mutation in a gene that increases cancer risk if they met one or more of the following criteria:

• Were under 45 years old at breast cancer diagnosis
• Had bilateral breast cancer (breast cancer in both breasts)
• Had triple-negative breast cancer diagnosed at 60 years old or younger
• Had a relative with ovarian cancer, sarcoma, or male breast cancer
• Had 2 or more first-degree relatives with breast cancer
• For patients who were diagnosed at age 50 or younger, those who were classified as high risk or had 1 or more first-degree relatives with breast cancer, Ashkenazi Jewish ancestry, or a family history of a mutation in a BRCA gene or other gene that increases cancer risk

All other women were classified as having an average risk of carrying a mutation in a cancer risk-increasing gene.

Study findings: 

1. 31% of the total study population were classified as being at high risk for carrying a gene mutation associated with increased cancer risk.
2. Among women who were diagnosed with breast cancer and were at high risk for carrying a gene mutation associated with increased cancer risk:
   • about 81% wanted genetic testing
   • about 71% talked about testing with a doctor or other health professional
   • about 40% had a session with a genetic counseling expert
   • about 53% had genetic testing.
3. Among women who were diagnosed with breast cancer, had a high risk for carrying a gene mutation associated with increased cancer risk, and were tested:
   • about 62% had a session with a genetic counseling expert.
4. Patients who were at high risk for carrying a gene mutation associated with increased cancer risk reported that they did not pursue testing because:
   • “my doctor didn’t recommend it” (about 56%)
   • “too expensive” (about 14%)
   • “I did not want it” (about 11%)

Individuals who were older or of Asian ethnicity were less likely to have genetic testing.

Limitations:

Because this study used self-reported survey results, the chance for error and bias exists. Additionally, only patients from Georgia and Los Angeles County were included in this study, so it is unknown if the results can be generalized more broadly. Finally, for the reasons why genetic testing was not pursued, this study only included the patient perspective and did not get the perspective from the healthcare provider.                         

Conclusions:

This study suggests that patients want genetic counseling and testing, but various reasons keep many of them from getting these services. Only 53% of women from this study who were at high risk for carrying a mutation in a gene associated with increased cancer risk had genetic testing. Also of note: only 40% of women at high risk for having a mutation had genetic counseling. More work needs to be done to understand why this occurs and how access to genetic counseling and testing can be improved. Meanwhile, patients who are concerned about carrying a mutation in a gene that increases cancer risk should talk to their healthcare providers and/or a genetics expert.

Posted 3/7/17

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