There has been a tremendous amount of interest and opinion
expressed about the potential benefits, harms and costs associated with
personal genomic testing.
Despite being on the market for nearly a decade, direct-to-consumer
(DTC) genetic testing continues to be controversial among experts and
raises concerns among health care providers and regulatory agencies.
‘Early adopters of direct-to-consumer (DTC) genetic testing understand the limited predictive impact of DTC results and do not over-react to very modest cancer risks.’
NIH-funded "Impact of Personal Genomics (PGen) Study" addresses these
concerns by empirically measuring the perceptions and tracking the
behaviors of individuals who have received DTC genetic testing from two
separate companies. Research from this large-scale prospective study has
already generated numerous new scientific reports. These findings shed
light on who seeks testing and why, and how they respond to the results
that they receive.
The latest results from the PGen Study were published in the Journal of Clinical Oncology
This was an analysis of how customers respond to common cancer risk
information (not Mendelian cancer risks like BRCA1/2), and was led by
Stacy W. Gray, City of Hope National Medical Center with senior
author Robert C. Green of Brigham and Women's Hospital, Broad
Institute and Harvard Medical School.
In this analysis, Gray and
colleagues specifically looked at personal genomic testing for cancer
risk, and found that 12-24% of individuals received "elevated"
cancer risk estimates for prostate, breast and colon cancer. Despite
learning they were at increased risk for these common cancers, most
customers did not report changing their diet, exercise, supplement use,
advanced care planning or cancer screening in comparison to the
customers who learned they were at average or lower risk.
exception is men who received elevated prostate cancer risk estimates as
some of these men changed their vitamin and supplement use more than
those at average or reduced risk. This counter-intuitive finding may
have resulted because the increased cancer risks reported to the
customers were very modest, and because the kind of individual who
purchases DTC genetic testing may already have been very proactive about
their health and using other available screening tests for cancer.
"These results suggest that people are not over-reacting to very
modest cancer risks in DTC genetic testing. This is consistent with
some of our other findings showing that early adopters of DTC genetic
testing understand the limited predictive impact of DTC results and do
not over-react either emotionally or in terms of generating additional
and unnecessary medical expenses," said Green, director of the
Genomes2People Research Program.
The PGen Study cohort is a group of more than 1,600 consumers who
purchased personal genomic tests prior to the imposition of FDA
restrictions in 2013 from 23andMe and Pathway Genomics (Pathway has
since changed their business model and no longer provides DTC testing).
In addition to sharing their actual test results with investigators,
participants completed surveys before receiving their results and again
two weeks and six months after receiving their results. The surveys also
presented mock results to determine if consumers could accurately
Study provided us with a goldmine of data on consumer expectations, how
consumers interpret, recall and experience their results, how their
results impact their state of mind, what actions they take after
testing, and how all of these factors change over time," said Green.
"As far as many of the speculated risks and harms around
direct-to-consumer genomic testing, we have not uncovered evidence that
they are either common or severe," added Scott Roberts of the
University of Michigan's School of Public Health, and joint principal
investigator of the PGen Study with Green. "Although we have found some
areas where informed consent for testing and communication of results
could be improved, our data suggest most consumers find their results as
potentially useful in informing future health decisions and advance