This brief article announces the discovery of a potential new and highly effective way to detect pancreatic cancer by looking for the presence of a certain type of protein in the blood. The article would have been much stronger had it included interviews with independent sources, and provided attribution for some of the statistics provided. Like the competing NBCNews.com and Los Angeles Times stories that we reviewed, this story passes along the claim that this test is 100% accurate. However, unlike those competing stories, this piece doesn’t in any way try to qualify that claim or address the study’s important limitations. That probably shouldn’t come as a surprise given evidence that the story leaned heavily on a news release.
Editor’s note 6/29/15: The story we reviewed herein was complemented by a more complete story published by the Houston Chronicle hours later. One thing that was better in the later piece was the addition of an independent perspective. That piece also went beyond the news release and included interviews with key experts. We wish the newspaper had alerted online readers that another version would be forthcoming. Even after learning of the later version today — 5 days after it was published — we revisited the original story and there’s still no mention of, nor link to, a later, more complete story. (At 11:48 a.m. on June 29, the newspaper did finally add a link at the top of the first story, reading, “An updated version of this story is available here.”)
Health news stories should attempt to critically analyze the results they report on, especially when those results involve extraordinary claims such as “100% accuracy” in a screening test. But it’s hard to provide critical evaluation when the coverage is based on a news release and independent sources are not consulted.
The study includes no mention of costs for the screening test. While it’s noted that the test has not yet been developed, it would be possible to give a ballpark figure based on similar screening tests.
The benefits of the tests are presented only in vague terms. The expert quoted claims that earlier diagnosis of pancreatic cancer would reduce death rates, but in the next sentence he states that a new screening tool also offers an “unprecedented opportunity” to design “potential curative surgical options.” That doesn’t give us a lot of confidence that curative surgical options currently exist. As we discussed in the competing NBC and LA Times reviews, patients whose cancers are caught early may still face long odds for survival. And the 100% accuracy figure touted in the story is based on a very small number of subjects. The story didn’t hint at any of this context.
Not only does the story neglect to mention harms, it asserts that the still-to-be-developed test is 100 percent accurate. But as the competing stories on this study pointed out, that figure is based on testing in a very small number of people under favorable conditions. We now know from many decades of increased use of screening tests that these tests are fallible and there’s no reason to to expect a new test would not offer up false positives and negatives when used in a broader population. Inconclusive and incorrect tests can lead to more invasive tests, increased patient anxiety and expensive and debilitating surgeries.
The story is bereft of any details of the study and its findings. It doesn’t tell us how many patient and control volunteers were in the study, volunteer demographics, what type of study it was, or any potential limitations of the research.
The story does not promote disease mongering.
The only expert quoted in the story is a coauthor of the study. We think it’s always prudent to consult an independent third party to vet claims. In addition, while the story includes some background on the prevalence and outcomes of pancreatic cancer, these reviewers were disappointed to see that these statistics were not sourced. There are a couple reasons why attributing sources of claims and statistics is important. Obviously, readers may want to do additional reading and providing a source points them in the right direction. Another reason it’s important to provide attribution is that statistics have been known to vary among advocacy groups, medical associations, companies, foundations and government institutions. It’s not unheard of for groups pushing for more awareness and funding to select a higher number – among those available – to further their cause.
The article refers to “various markers” that are used to detect pancreatic cancer in a blood test but calls them too unreliable for widespread screening. The article is consistent with others in stating there currently is no reliable test available.
The article is clear that the test is not yet available. In reporting on the finding, the story states that “If such a test were developed, it would likely be used first to test patients at high risk for pancreatic cancer” and adds that it still needs to be shown that the screening would improve outcomes for patients with pancreatic cancer. The story contains a lot of conjecture for a test not yet developed.
The story suggests that if the screening test were developed, it would be a more effective tool for detecting pancreatic cancer. Again, it’s a big “if,” but the story doesn’t hide that fact – to its credit.
Because the story quotes just one source, the chair of MD Anderson’s Cancer Biology department (the institution that issued a news release for the study), and those quotes can be found in the news release, we believe the story relied too heavily on the release.