This Wall Street Journal story offers a thoughtful and thorough summary of a presentation (and related study in JAMA) about the ability of commercial prenatal blood tests to also uncover hidden cancers in pregnant women. The story makes clear that the study’s finding of “rare cases” of cancer “underscores both challenges and opportunities” for the tests, particularly those related to the tests’ potential to reveal elevated risks for future diseases. Other stories, including one from CBS News, focused more viscerally on the handful of mothers whose hidden cancers were detected by the fetal blood work. While stories focusing on such vignettes may pack a significant emotional punch, they also may leave readers with an exaggerated sense of these tests’ cancer-finding ability and the risk that most women face. As demonstrated by the WSJ coverage, there are many ethical and social issues raised by widespread DNA testing that also merit discussion.
There is increasing demand by physicians and pregnant women to perform noninvasive prenatal blood tests as a safer means of establishing fetal risk for Down Syndrome and other serious genetic abnormalities. Although professional guidelines suggest that only women at high risk of carrying fetuses with serious genetic abnormalities get these tests, they are already widely used because other procedures, such as amniocentesis, can occasionally lead to miscarriage. The discovery that in a few rare cases, the abnormalities detected in the tests have nothing to do with the fetus, but with a mother’s undiagnosed cancer instead, will likely lead to even more demand for use of these tests. That poses not only the ethical problem of whether and when to divulge incidental genetic risks also uncovered in maternal DNA (say, of breast cancer), but also a potential explosion of costs related to use of the blood tests to screen every pregnant woman to find a very small number of cancers.
Although the story does not explicitly note the cost of the two commercially available tests, it does provide substantial context about the rising popularity of the tests among clinicians and pregnant women, as well as cautionary notes about their use from both those involved in the study and an expert who wrote an accompanying editorial to the JAMA article.
The story clearly explains that the eight cases of maternal tumor DNA findings came from a collection of more than 125,000 blood samples submitted to one of the companies over a two-year period, and that about 3 percent were positive for one or more chromosomal abnormalities. It also points out that follow-up tests showed the fetus was normal in a “very small number of instances” and that among those just 10 cases of maternal cancer were suspected. Further, of the eight women featured in the published report, just three had their cancers diagnosed because of the findings.
The story earns a Satisfactory grade here. Some additional questions that could have been addressed by the coverage include:
The WSJ article very explicitly notes that there are harms from invasive prenatal tests, although it does not give rates of miscarriage; and it goes into welcome detail about the challenges of giving women genetic risk information for themselves or their infants based on the noninvasive blood test, noting “there is no consensus on when or how to inform” patients of such findings. On the other hand, the story explains, if maternal tumor DNA is detected, the need to inform the mother may be urgent and life saving.
The story gets a passing grade here. It adequately describes the study and notes appropriately that “the full implications of the new findings need further study.” Some discussion of the strengths and limitations of the study design, and what additional information is needed to inform clinical practice related to these tests, would have been welcome complements to the coverage.
The story never suggests that fetal chromosomal abnormalities or maternal cancers uncovered by the blood tests are a major threat. Unlike the CBS story, WSJ notes that the cases identified in the study were culled from more than 100,000 samples and that such findings are “rare.” The tone of the story is cautious and it quotes experts who call for further studies and conversations about the current and potential use of diagnostic prenatal blood testing.
The story importantly refers to “ongoing debates” within the medical and scientific community about the wider use of the blood tests, and quotes an editorial written by an expert who did not participate in the study itself. However, while the story notes that the study was funded by Illumina, which markets the test, it did not alert readers that Dr. Bianchi, the study author who is quoted in the piece, is a paid advisor to the company. CBS, by contrast, made note of that relationship. We reluctantly grade the story Not Satisfactory based on that omission.
The article explains nicely the major alternatives to the fetal blood tests and also mentions both companies that market the test.
Again, the story could have benefited from some cost information about the tests and whether they are covered by most insurance plans. It also would have benefited from a sentence about how women can best arrange for such testing, and how widely available they are at prenatal clinics and private practices. But it does give information about the total number of tests done in the U.S. and about their growing popularity.
The story points out that the findings are new and serendipitous, then ties them in nicely to the broader issue of maternal and fetal DNA testing and the serious debate about testing’s benefits and potential harms.
There was a JAMA release on the study, but the story also appears to be solidly based on a presentation at a scientific society meeting and the JAMA article and accompanying editorial.
Systematic, Criteria-Driven
@garyschwitzer has been a trailblazer in protecting us from bamboozled health reporting. Thrilled to get his endorsement here for #Malcharist, which fictionalizes problems he first helped us see. https://twitter.com/garyschwitzer/status/1310190671555375109
Major revisions + reversals of reporting about the efficacy of remdesivir and HCQ have compromised the public's trust in scientists and physicians. Complexity and caution are key to public #COVID19 communications @garyschwitzer https://ja.ma/3fzUW0M
Comments
Please note, comments are no longer published through this website. All previously made comments are still archived and available for viewing through select posts.
Our Comments Policy
But before leaving a comment, please review these notes about our policy.
You are responsible for any comments you leave on this site.
This site is primarily a forum for discussion about the quality (or lack thereof) in journalism or other media messages (advertising, marketing, public relations, medical journals, etc.) It is not intended to be a forum for definitive discussions about medicine or science.
We will delete comments that include personal attacks, unfounded allegations, unverified claims, product pitches, profanity or any from anyone who does not list a full name and a functioning email address. We will also end any thread of repetitive comments. We don”t give medical advice so we won”t respond to questions asking for it.
We don”t have sufficient staffing to contact each commenter who left such a message. If you have a question about why your comment was edited or removed, you can email us at feedback@healthnewsreview.org.
There has been a recent burst of attention to troubles with many comments left on science and science news/communication websites. Read “Online science comments: trolls, trash and treasure.”
The authors of the Retraction Watch comments policy urge commenters:
We”re also concerned about anonymous comments. We ask that all commenters leave their full name and provide an actual email address in case we feel we need to contact them. We may delete any comment left by someone who does not leave their name and a legitimate email address.
And, as noted, product pitches of any sort – pushing treatments, tests, products, procedures, physicians, medical centers, books, websites – are likely to be deleted. We don”t accept advertising on this site and are not going to give it away free.
The ability to leave comments expires after a certain period of time. So you may find that you’re unable to leave a comment on an article that is more than a few months old.
You might also like