Compared to other stories we reviewed on a study ofthe potential benefits of aspirin for reducing cancer, this one presented an optimistic take on the potential benefits of daily aspirin and provided few caveats. Unlike the NPR Shots story, it failed to quantify the harms, and unlike the WebMD story, it failed to define the scope of cancer deaths.
The study itself nicely states the reason cautious reporting on new cancer treatments matters. “In the developed world, the lifetime risk of cancer is about 40%, and rates are increasing in the developing world. In Europe, about 3.2 million new cancers present
This story does not discuss the cost of daily aspirin intake. Because the cost to individuals is low and well-known, we won’t insist on this point. Nevertheless, were a recommendation made for everyone to begin taking aspirin daily starting at age 45 the national price tag would be substantial. Readers would also benefit from an acknowledgement that such a recommendation would lead to higher spending on treatment of bleeding ulcers and other adverse events that would offset some of the potential cancer-related savings.
The story does not adequately quantify the potential benefits. For one, the story relies to heavily on the relative differences between the aspirin group and the placebo group. As the study itself notes, for some of the cancers studied, the number of deaths in both groups was quite small – 16 versus 14, 10 versus 19, 15 versus 19. This story and the other stories reviewed should have made this clear. What’s more while the story highlights the total number of participants included in the data analysis (25,570) it doesn’t tell readers that only 674 of them died of cancer. And then for the longer-term follow-up there was a total of 1634 cancer deaths among 12,659 participants. Overall, the study that 3 percent of the patients in the control (placebo) group died of cancer during the original trials, compared to 2.3 percent of the patients who were assigned to recieve aspirin. Yes, that is a 23 percent reduction overall, but a 0.7 percent absolute reduction. Put another way, if indeed aspirin is preventive, you would need to treat 150 people to prevent one death from cancer during that time period. The way this story is written creates an inflated impression of the potential cancer prevention benefits of aspirin seen in this study.
The story did say, “But even as some experts hailed the new study as a breakthrough, others urged caution, warning people not to start a regimen of aspirin without first consulting a doctor about the potential risks, including gastrointestinal bleeding and bleeding in the brain (hemorrhagic strokes).” It could have put a number to these harms, as the NPR Shots story did.
This story includes praise for the study because it is based on randomized controlled trials, rather than observational studies. But it never tell readers that the randomized controlled trials investigated aspirin’s effects on heart disease, not cancer. The authors of this study took the patient data from several old trials and then used sophisticated statistical methods to combine the data. They also used death records to allow for a longer follow-up than was included in the original trials. The methods used for this study do have some notable advantages over previous, mostly observational, studies of aspirin and cancer; but they also have important limitations. Readers of this story would likely believe that all of the data used for this study was collected with cancer in mind. It was not. Readers should have been cautioned about the potential pitfalls and limit re-purposing scientific data.
The story does not engage in disease-mongering.
The story does quote some outside experts and includes this important comment: ““Many people may wonder if they should start taking daily aspirin, but it would be premature to recommend people starting taking aspirin specifically to prevent cancer,” said Eric J. Jacobs, an epidemiologist with the American Cancer Society.” We think that, on balance, comments like that were overshadowed by the comments from the study’s author. ““This is important as a proof of principle that a single simple compound like aspirin can reduce the risk of cancer substantially,” said the study’s lead author, Dr. Peter M. Rothwell, professor of neurology at the University of Oxford. “There’s been a lot of work over the years showing that certain compounds can increase the risk of cancer, but it’s not been shown before that we can reduce the risk with something as simple as aspirin.”” Nevertheless, it meets the basic requirement on this criterion. However, it should have noted that while there was no outside funding for this study, some of the authors have ahd consulting relationships with pharmaceutical companies.
This story does not present alternative ways of reducing cancer risk. Some other news reports specifically noted that avoiding smoking and obesity are both known to reduce cancer risk.
The story makes it clear that “Many Americans take aspirin to lower their risk of heart disease” but not necessarily for a cancer benefit.
The story establishes the novelty of using aspirin as a cancer prevention measure.
This story does not appear to rely on a news release.