This is a story about a study that found that aspirin decreased the incidence of colorectal cancer in a group of individuals with a specific genetic mutation that predisposed them to develop this cancer.
While the story meets many of our criteria, we find two gaping holes:
Although a precise cost was not mentioned in the story, aspirin was described as ‘cheap’. That’s OK; we’re confident that people know this.
The actual rates of colon cancer were not given. Circuitously, readers might be able to piece this together – if we can assume that half of the 1,000 people studied got aspirin and half got placebo pills. So one might assume that six people in about 500 on aspirin got colon cancer versus 16 in about 500 in the placebo group.
But the abstract of the talk which we found online stated that "long term followup data have been accumulated on 628 of the cohort" – so we don’t actually know what the rates were that were presented in the talk.
This is one of the weaknesses in reporting on studies presented at meetings but not yet published.
The story needn’t be circuitious and needn’t make readers assume or make them do the math.
Why not just spell out the actual rates and the actual numbers?
Although there was no mention of any harms of taking aspirin that were seen during this particular study, the story did mention that "Aspirin can cause significant side effects if not used as directed by a doctor" and the fact that "it can irritate the stomach and intestines and cause major bleeding."
The story didn’t make clear that the results haven’t yet been evaluated by the scientific community. And because the story is based on a talk at a scientific meeting, we could only find an abstract online – an abstract which raises questions in our mind about the actual rates of cancer found – something not made clear in the story. See criterion for "Quantification of Benefits of Treatment" below.
The story included this quote: "This doesn’t mean that everyone should start taking aspirin if they’re worried about bowel cancer," said Henry Snowcroft of Cancer Research United Kingdom.
The story included comments from clinicians and researchers who were not involved in the study reported.
The story did not mention the lack of options for colorectal cancer prevention. The guidelines about frequency of screening in this particular cohort or the general public were not discussed as part of this story.
The story appropriately reminds readers that "aspirin has been used widely for years to treat minor aches and to alleviate fevers."
At the end of last year, the same group of investigators (J Burn, first author) published a paper in the New England Medical Journal which found aspirin had no effect on incidence of colorectal cancer in apparently the same group of individuals with Lynch Syndrome.
It should have been mentioned that the outcome at 4 years failed to show differences between the group whereas an examination of the data at a later time point may suggest a benefit from the treatment. "May suggest" is an important point here because it is not clear that the investigators accounted for the fact that the difference reported may have arisen simply by chance.
Because numerous sources were interviewed, it’s safe to assume the story did not rely solely or largely on a news release.