This story is about a study of a new test for pancreatic cancer. It covered a lot of ground in a short space. It included many voices and a lot of good background about pancreatic cancer. It missed some big areas, though, including the potential costs of the tests and treatments for the disease, the quantification of the benefits, and any explanation of harms that would come from widespread screening for pancreatic cancer. It was stronger than a competing story from the Houston Chronicle about this study, and similar in quality to a competing LA Times piece.
Pancreatic cancer is a deadly cancer that often presents insidiously. By the time of diagnosis the cancer is often advanced and incurable. There are no current screening tests for detecting early-stage cancer. A tumor marker that can both detect early cancer and monitor treated patients for cure/recurrence would potentially have great value.
There is no mention of costs in this story. No costs for the test. No costs for the downstream treatments and surgeries. If a researcher is going to be quoted as saying a clinical test could be on the market in a year, there should be some mention of costs.
The story does not actually quantify the benefits of this screening test. It skirts the issue by saying that the test detected cancer in 100% of the people who were known to have cancer. That description isn’t inaccurate, but it doesn’t fully (or fairly) convey what would be the true value of a screening test: detecting cancer at an early — potentially curable — stage. The story suggests that the test might have saved the life of Dr. Teresa Flippo-Morton, a prominent breast surgeon from Charlotte, N.C., whom we presume has died of invasive pancreatic cancer (although this is never explicitly stated, and the story later suggests her life could still perhaps be saved). That’s problematic, because while the test identified all of the people known to have cancer, only 5 patients in the study had early stage cancer. (The story states, erroneously it would seem, that there were 7 such patients.) That’s a very small sample from which to draw conclusions about the value of the test. In addition, while patients who are able to undergo early treatment might be cured of the disease, the NCI cancer summary points out that the 5-year survival rate for patients who underwent complete resection for small pancreatic tumors that were confined to the pancreas (the target for screening) was still only 18 to 24%. So, patients may still face long odds even when their tumors are caught early — context the story could have provided.
The harm from screening and treatment is an important issue — these are major surgeries (which are best performed by skilled surgeons at high-volume centers) that are associated with mortality rates of around 4% and multiple morbidities. While the test was 100% sensitive and specific in the study, in the real world there will be false negatives and false positives–and possibly indeterminate results. We also do not know whether there is any risk of overdiagnosis (detecting cancers that would never cause a problem).
But there was no mention in the story of the potential harms. The logical extension of the approach advocated in this piece is that all people should be screened for pancreatic cancer. If that is what the researchers and the other commentators in the piece believe, then they should also address the issue of unnecessary surgeries, side effects from treatments, and the anxieties caused by mass screening. A more reasonable point of discussion in the piece might have been to suggest developing a screening protocol for populations known to be at risk. For example, people who smoke, are obese, or who have diabetes are all more likely to be diagnosed with pancreatic cancer. An effective and cost-effective screening program would need to determine which people to target (including whether a person is healthy enough to undergo surgery) and at what age.
The story earns credit for including skeptical comments from Dr. Wolpin about the limited applicability of the results. He notes that “In this study the patients were known to have cancer or not to have cancer. In this kind of sample sensitivity and specificity tend to look good.”
But while those comments are on-target, they come at the very end of the story and feel bit like an afterthought to the strong language throughout the rest of the piece, essentially heralding this test as a possible cure for cancer. The very first sentence says, “With just a drop of blood doctors may one day be able to detect pancreatic cancer in its early stages, before it has become deadly, a new study suggests.” Then later it says, “But, by good fortune, the protein turns up in exosomes only when there is cancer, so its presence could be an early, and testable, marker for the disease.” The story even suggests that the test could have saved the life of a prominent surgeon. Such enthusiasm is a bit out of balance with the quality of evidence on display here, some of which was based on mouse models. This test is far from ready for use in clinical practice.
We wish more stories took the time to explain to readers how common or rare a condition is. This story gets high marks for pausing to say, “For perspective, over the course of a lifetime, 1.5 percent of Americans will develop pancreatic cancer.”
We give the story a pass here because there are multiple voices in the piece. But it should be noted that there was only one dissenting opinion, at the very end, from Dr. Brian Wolpin, of the Dana Farber Cancer Institute. He brought up the point that should have been in the second paragraph of the story: “In this study the patients were known to have cancer or not to have cancer. In this kind of sample sensitivity and specificity tend to look good.”
There is no mention of alternatives in this story or whether other research has gone in this direction and failed to yield a marketable test. While there really aren’t any good screening tests, there is another tumor marker (CA 19-9) that has been used for screening, but it does not readily detect the early-stage cancers. The study actually compared the new test with CA 19-9.
We were surprised to see mention in the story that a clinical test could be available within a year. Given that the test will need to be further validated in a much larger group of study subjects, we think that’s very unlikely. The story does frame the comment as “just speculation” and notes that additional research will be needed. We’ll give the benefit of the doubt.
The findings are presented as novel, but novelty is not established. There’s no discussion of whether there has been other research into tests for pancreatic cancer and how the new test builds upon those previous efforts. We can infer that this is new, but the context is not established.
The story does not rely on a news release.