Most People Do Not Change Behavior After At-Home Genetic Tests, Study Finds

Few People Change Diet, Exercise or Get Additional Screening After Seeing Results
Breast Cancer News
November 20, 2017
By: 
Eric Fitzsimmons, Copy Editor and Content Coordinator
Reviewed By: 
Robert Cook-Deegan, MD

A study published in the Journal of Clinicalinfo-icon Oncologyinfo-icon found that most people do not change their behavior after getting information on their hereditaryinfo-icon breast cancer risk from an at-home genetic testinginfo-icon company.

Background

Genetic testing helps people identify if they face a higher risk of breast and other cancers because of mutations in certain genes. Test results often allow people make more informed decisions about cancer treatment and preventioninfo-icon.

Usually, genetic testing is done if you have been diagnosed with breast or ovarian cancerinfo-icon, at a young age, if there have been multiple cases in your family, or if someone in your family has already tested positive for a geneinfo-icon mutationinfo-icon related to inheritedinfo-icon risk of cancer. The results are usually shared with you by a geneticinfo-icon counselor, a healthcare professional trained to weigh the benefits of testing and discuss your results.

But recently, genetic tests have become more accessible for people to order directly to their home without having to go through a doctor or genetic counselor — though some companies do provide access to a genetic counselor along with the test.  

Healthcare professionals worry about people getting sensitive information about their health — such as risk of cancer that might lead to removal of breasts, ovaries, or parts of their large intestines — without speaking to someone trained in interpreting the results. People may not know the science behind some tests, the degree of accuracy of the test, or most importantly, what the results really mean in terms of cancer risk. Some experts believe at-home tests may convince people they need procedures that may not help them lower their risk at all.

Design

The Impact of Personal Genomicsinfo-icon (PGen) Study looked at what people did after they got the results of an at-home genetic test.

People buying their first tests from the companies 23andMe and Pathway Genomics were invited to participate in the study. They were

  • men buying tests for prostate cancer risk
  • women buying tests for breast cancer risk
  • men and women buying tests for colorectal cancer risk

None of the participants were diagnosed with cancer, and none had previously gotten genetic testing.

Participants completed one survey before they received their genetic test results, did another survey 2 weeks after seeing their results, and did a third and final survey 6 months after initially getting their results. The surveys asked about different areas of behavior that people might change after hearing about their risk of developing cancer

  • diet
  • exercise
  • health and estate planning
  • vitamin and supplement use
  • cancer screenings

The researchers sorted participants into two groups

  • people found to have a higher risk of cancer
  • people found to have an average risk of cancer, or lower

For Pathway Geneticsinfo-icon, the higher risk group included everyone who had a test that showed uncertain link to cancer, a probable link to cancer or a gene mutation that has been linked to cancer. For 23andMe it was anyone found to have a risk of cancer at least 20 percent higher than average.

Results

Researchers found that people who were told they had a higher risk of developing cancer were not more likely to change their behavior in the 6 months after receiving a score than people found to have an average or lower risk. Likewise, women who had a higher risk of breast cancer were less likely than those of average or lower risk to change their diet or their use of vitamins and supplements. Just over 25 percent of women with a higher risk score changed their exercise habits, which was about the same as women who did not have a higher risk score. 

Women with a higher risk of developing breast cancer were less likely than those classified as average or lower risk to get a mammograminfo-icon between getting their results and the 6 month follow up:

  • 18 percent of women with average or lower risk got a mammogram.
  • 11 percent of women with a higher risk of cancer got a mammogram.

 Only one category showed people with a higher risk of cancer as more likely to change a behavior than people with an average or lower risk: Men with a higher risk of prostate cancer were more likely to change their use of vitamins and supplements.

The study only asked about behaviors up to 6 months after people received their test results. It did not ask about other screeninginfo-icon methods, considerations that may have delayed screening or other actions that could have been taken, like genetic counselinginfo-icon or surgeryinfo-icon.

What This Means for You

If you have been diagnosed with breast cancer you may have spoken about genetic risk with your doctor.  It may have been suggested if you were diagnosed at a young age or have several people in your family who had breast cancer, especially if any were men.   

At-home genetic testing gives more people quick access to information, even if there is no sign of a genetic change linked to cancer in your health history. But test results are just a part of your cancer risk and your treatment decisions. While some genes, like BRCA1info-icon and BRCA2info-icon, have been studied thoroughly, doctors are studying many other genes that may, when there are certain variations, increase your risk of getting breast cancer. Some of these have not been identified yet. Working with a genetic counselor may help you learn about other possible genetic risks and help doctors identify genetic changes for the future.  

This study found most people do not change their lifestyle or health decisions after getting an at-home genetic test. This may ease some concerns for policy makers and make it more likely at-home tests will continue to be available directly to the public. But the study also found people were not more likely to get a cancer screening even if the test said they had a higher risk.

You may have heard about at-home genetic tests from a friend and wondered if you should try it. Before ordering one of these tests, ask your doctor if you can speak with a genetic counselor or for other resources on genetic cancer risks to learn more about what these tests can actually tell you and what they do not. And if you’ve been diagnosed with cancer already, your genetic test results could lead you toward treatment decisions to lower your risk of a second cancer. Deciding whether to have additional treatment like surgery can be overwhelming. Your care team is there to help you figure it out.

If you have concerns about a specific disease, a knowledgeable doctor or genetic counselor can speak to you about your risk and if testing is appropriate. And if you do get tested through a healthcare providerinfo-icon, they can speak with you about other factors that affect risk and what actions are appropriate for your test scores and health history. You can learn more about genetic testing in LBBC’s Guide to Understanding Genetics and Family Risk.

Gray S., Gollust, S., Carere, D., et al. Personal Genomic Testing for Cancer Risk: Results From the Impact of Personal Genomics Study. Journal of Clinical Oncology. February 2017. doi: 10.1200/JCO.2016.67.150

You must have Javascript enabled to use this form.

More In Genetic Tests

Media: Audio
audio
October 16, 2018
Article August 31, 2015
Additional Related Topics 
DIAGNOSIS