A strong story that describes in clear terms the findings as well as the strengths and weaknesses of this study. It covered potential biases that could not be controlled, mentioned harms, and was overall very cautious. It would have been even stronger had it mentioned that the study was observational in nature and therefore not capable of telling us whether the aspirin, or some other factor, is responsible for the benefit that was seen. It also did not mention alternatives for colorectal cancer prevention such as proven effective screening practices. But these are relatively minor omissions in coverage that was otherwise quite exemplary.
Though evidence has long indicated that low-dose aspirin was associated with a reduced incidence of the disease, this is the first report to say how long the regimen needs to be followed.
No mention was made of costs, but anyone who has been to a drugstore knows that aspirin is cheap.
The story cites a 27 percent decrease among low-dose aspirin users who had taken the drug for five years or more. It also notes the incidence of the disease among different populations, and even gives readers a link to a risk calculator to determine their individual risk.
Of course, we almost always prefer stories to use absolute risk reductions over the relative risk reduction reported here (technically an odds ratio — not a “risk” reduction per se). But in a case-control study such as this one, the issue can be complicated. We’ll give the benefit of the doubt.
The story is straightforward in saying that all NSAIDs carry risks.
“Long-term use can cause gastrointestinal bleeding, for example, so the potential reduction in colon cancer risk needs to be balanced against potential side effects, the authors warn.”
It would have been easy to also mention cerebral vascular bleeds, but that’s a minor point.
The story cites “several limitations” of the study, including the fact that the researchers did not include patients who bought their aspirin or other NSAIDs without a doctor’s prescription, and that the authors were not able to adjust for some risk factors, such as obesity, diet, alcohol use and family history of colorectal cancer.
The study type (retrospective case control) could also have been mentioned along with the relative weakness of this type of study compared with a randomized controlled trial. In addition, the story in several places uses language suggesting a cause and effect relationship between aspirin and colon cancer — e.g. “taking low-dose aspirin continuously for at least five years appeared to reduce the risk of colorectal cancer” — and it quotes an independent source who says flatly that aspirin “reduces the risk of colorectal cancer.” Such a strong statement wasn’t justified by anything we saw in this study — and the paper didn’t point to any other definitive evidence that would warrant such a statement.
But despite these concerns, we think that the story overall did enough to merit a Satisfactory rating here.
There is no attempt to inflate the incidence or severity of the disease. If anything, the severity of the disease was underplayed by not mentioning death rates.
The story includes comment from Dr. Gurpreet Singh-Ranger, who apparently was not involved with the study, so we’ll give it a pass. The story would have been stronger had it told the reader what made him an authority on the topic.
The story makes no reference to colonoscopy as a means of identifying and removing polyps before they become cancerous. Other screening approaches that could have been mentioned include sigmoidoscopy and fecal blood tests.
The ubiquity of low-dose aspirin is so well known that it did not need to be mentioned.
High up in the story, the reader is told what is new about this study: “Earlier studies had suggested that aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen may help protect against colorectal cancer, but it wasn’t clear how much had to be taken, and for how long, to achieve those benefits.”
The fact that the story includes comments made directly to Reuters Health shows that it does not rely on a news release.