This is another one of those stories that will leave readers’ heads spinning. In the opening sentence, we learn that takings NSAIDs “appears to significantly lower the risk for developing several major forms of skin cancer.” And throughout the story, there is reinforcement of the message that higher-dose users “appeared to benefit from the strongest protective effect.” But then in the last sentence, the story seems to take it all back by claiming that the study “did not prove a cause-and-effect relationship” between NSAIDs and cancer.
So which part of the story should we believe — the part that consistently uses cause-and-effect language to describe the relationship between NSAIDs and skin cancer, or the out-of-context line at the end that tells us there was no such relationship? The message would have been a lot clearer if the story had avoided using cause-and-effect language– “may help prevent”…”lowers risk”…”appeared to benefit” — throughout.
The absence of discussion of harm is a second major drawback.
It would be great if we could add skin cancer prevention to the list of benefits associated with regular use of anti-inflammatory pain drugs. These drugs are cheap, widely available, and many people are already taking them for prevention of cardiovascular disease. The evidence presented here, however, is far from the final word on the matter.
NSAIDs also have potential for serious harm in the form of bleeding risk. All meds should be taken with caution, and there are other very effective ways of reducing skin cancer risk.
The cost of NSAIDs is not in question.
The story cites statistics appropriately, but mischaracterizes what the data mean. The story tells us that skin cancer risk “fell” or “dropped” in those taking NSAIDs, suggesting that that we know that the lower risk came after the subjects took NSAIDs. With this type of study design, however, we can’t be sure of the timeline. All we know is that the researchers tracked NSAID prescriptions and cancer diagnoses — we don’t know if the cancer developed before or after the subjects took the pills. Which is why it’s inappropriate to suggest that cancer risk “fell” in the subjects who used NSAIDs, because we don’t know for sure if the NSAIDs had anything to do with it.
There was no discussion of the harms associated with long-term use of aspirin, including bleeding in the gastrointestinal tract and brain. The suggestion that “most” people are already taking aspirin for cardiovascular disease prevention is also potentially misleading, since regular aspirin use is recommended primarily for those at higher risk of heart disease.
There were some efforts to inject caution into the reporting, but not enough to overcome the passages that oversold the findings and drew conclusions that this study can’t support. The story provides no sense of where this study, which features a fairly weak case-control design, sits in the hierarchy of medical evidence.
By the time the appropriate final line rolls around – “While the study found an association between skin cancer risk and NSAIDs, it did not prove a cause-and-effect relationship” – the story had already used causal langauge throughout, such as:
Each of these statements required editing or quotes required counter-explanation about the limitations of observational data.
An independent expert was quoted, although unfortunately his comments tend to reinforce the story’s exuberance rather than restrain it. Why this private practice dermatologist was chosen as the one independent expert is unknown. Does he have a research background? The quote doesn’t offer any evaluation of the evidence.
The story mentions sun protection as a key method of preventing skin cancer.
The availability of NSAIDs isn’t in question.
The story mentions previous research suggesting that these drugs may have anti-cancer effects.
The story includes interviews with one of the study authors and an independent expert. It was not based on a press release.