Readers of this story gets a fairly detailed description of a study that looked at medical records of prostate cancer patients to see if the use of anticoagulant drugs, including aspirin, was associated with any differences in outcomes. However, readers also get a headline and lead that leap to the conclusion (unsupported by this study) that aspirin may cause death rates to drop. The story also misleads readers by failing to point out that what the researchers reported were differences in deaths from prostate cancer, not deaths overall.
The caution about the relative lack of peer review scrutiny of studies presented at medical meetings is welcome.
Is there some important difference between prostate cancer patients who take aspirin or other anticoagulants and those who don’t? And could that difference explain some or all of the differences in death rates? This type of study can’t answer that question. This story should have, but didn’t, highlight that limitation.
A story that says that aspirin seemed to account for more benefit than far more expensive drugs certainly should address the cost differential between the inexpensive "ubiquitous…pedestrian" drug and others. Cost was never mentioned.
When reporting the results of observational studies, it is important to avoid saying the results show cause-and-effect, when such studies can only identify associations. This story flunks that test by saying the study suggested that aspirin and other anticoagulants “may cut the risk of dying.” Indeed, the story quotes the researcher saying it would be premature to recommend treating prostate cancer patients. The story should have put that caveat near the top of the story, rather than burying it.
The story further errs by stating that those who were taking anticoagulants had lower death rates. What the researchers actually reported was only the death rates from prostate cancer, not how many of the men overall were still alive after several years.
On the plus side, this story tells readers how many men were included in this research analysis. It also reports the actual differences in death rates, not just the relative differences (though as noted above, the researchers actually reported differences in death rates from specifically prostate cancer only.) Still, the story emphasized relative risk reduction twice in the story – "risk of dying from cancer was reduced by more than half" and "this translates to a risk reduction of about 50 percent." That seems pointless when you’ve already provided the absolute numbers.
The story does mention that aspirin comes with risks, including stomach bleeding, so it might barely meet this criterion. However, the mild warning minimizes the risks in some frail or elderly individuals, where gastrointestinal bleeding can be lethal. The story left out a comment from the researcher that anticoagulants increase the potential for rectal bleeding in patients treated with radiation, which seems like an important consideration for men diagnosed with prostate cancer. Calling aspirin "pedestrian" in the first line is inadequate in the context of potential harms. There’s nothing "pedestrian" about the catastrophic bleeding that may occur in some people.
This is one of the areas in which this story was on the doorstep of a satisfactory score, when it stated that "Retrospective studies…looking for associations are not as reliable as prospective trials." But it never went any further to explain why and to explain that such studies CAN’T establish causation. It failed to make clear the tentative and limited nature of the conclusions and the vital questions that this type of study is incapable of answering. The story erroneously reported that the researchers reported differences in death rates, when actually they reported only the differences in death due to prostate cancer. There were no figures released about other causes of death.
This study looked only at the medical records of patients (including anticoagulants prescribed for other health conditions) and was not a randomized trial. Readers should have been clearly alerted that there may be important differences between the patients who were taking anticoagulants and those who weren’t… and that those differences might affect or explain the observed differences in prostate cancer outcomes.
The story should not have used the comment from the researcher about men who already take asprin perhaps getting an additional benefit without also including the rest of his comment during the news briefing: that first this study needs to be followed up by prospective studies to see if the findings hold up… and if so, what type, dose, and duration of medication might be best.
This story does include a cautionary note at the end that studies presented at scientific meetings do not go through the same kind of peer review used by leading medical journals. It also includes a comment from the researcher that it is premature to recommend aspirin as standard therapy from prostate cancer patients.
The story was clear that this study involved only men who had been diagnosed with prostate cancer and that it was in those with the highest-risk tumors where the differences were most apparent between those who were on anticoagulants and those who weren’t. It would have been a good idea for this and the competing WebMD story to state how many men are diagnosed each year with prostate cancer and how few actually die of the disease; most men diagnosed with prostate cancer are not destined to die of their prostate cancer.
The story does not quote any independent sources.
The researchers say it would be premature to recommend the use of anticoagulants in prostate cancer patients, because the benefits and risks have yet to be clearly identified… and so it is also premature to expect comparisons to alternatives.
The study looked at the use of available anticoagulant medications.
The story notes that lab tests and other clues about cancer and blood coagulation have suggested that anticoagulants might have some effects, but that there has been little work that looks at these questions in people who have tumors that have not spread beyond the prostate.
The story uses quotes from a news conference, not just what was written in the news release. However, it repeats the inaccurate wording of that news release in saying the study showed aspirin and other anticoagulants may cut the risk of prostate cancer death, when the researchers were careful to note that they only identified an association between anticoagulant use and lower prostate cancer death rates, not whether one caused the other.