Aspirin is one of the most well-studied drugs on the planet, in terms of treating headaches, aches, and pains as well as in helping out those who are at risk of heart disease — the biggest killer of people in developed nations. This release promotes a study that looks at the common drug’s effect on the second-biggest killer, which is cancer.
The meta-analysis crunched the data of five randomized trials and 42 smaller studies that focused on colorectal, prostate, and breast cancers and — most importantly — the effect of a low-dose aspirin regimen on the survival of those patients, as well as how their cancer spread over a period of about 5 years.
The correlation is eyebrow-raising, with a reduction in death and cancer spread in the neighborhood of about 20%.
On the downside, this release doesn’t really get into what might be causing this reduction, or even define what “low-dose aspirin” means. It also doesn’t adequately discuss the risks (e.g. bleeding, allergies, and stomach ulcers) and skips over a couple of other basics that would have been helpful to journalists and readers alike.
Behind heart disease, cancer is the biggest killer of people in developed nations. Each year the disease kills about 176 in every 100,000 people in the UK, and roughly 171 in every 100,000 people in the US. Any treatment that that can improve survival — especially low-cost, non-invasive methods — deserves attention.
Aspirin is one of the best-studied drugs on the planet, and its risks and side effects are as well known as a preventative treatment for people who are at risk of heart disease, or who’ve had strokes or heart attacks before.
Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) have been studied for use in the prevention of cancer. The best data exists for low-dose aspirin and colorectal cancer prevention. The US Preventative Task Force released a final recommendation in April 2016 suggesting certain adults (ages 50-59) might reduce their risk of developing both colorectal cancer and cardiovascular disease if they undertake long-term use (10 years) of low-dose aspirin. The current study examines whether aspirin could improve survival among patients who already have cancer. The authors suggest benefit but admit that the data is limited and mainly comes from observational studies.
The release doesn’t touch on cost but because aspirin is so widely available, and its cost so minimal, we’ll mark this one “not applicable.”
We’re told that, during a given span of 5 years, a low-dose aspirin regimen in a patient with colorectal, prostate, or breast cancer is associated with a 15-20% reduction in death and spread of cancer. We generally want to see absolute (actual number of patients or volunteers) as well as relative risk reduction numbers. However, the study only provides relative risk data. Nevertheless, we think it’s incumbent upon news release writers to present benefits data in terms that are meaningful for readers. And if those results aren’t included in the study being described, news release writers should press their sources for more detailed and complete information.
The only risk of harm in the release is a passing mention of intestinal bleeding in cases of colorectal cancer.
Briefly mentioning the handful of other risks would have greatly improved this release. Even small doses (80-325 mg) of aspirin can reduce the body’s ability to clot wounds, and consequently promote bleeding. Giving aspirin to patients being treated for cancer may be presumed to increase bleeding risk, especially if the patient has low platelets as a result of chemotherapy.
Some people are also allergic to aspirin, which can complicate asthma. A regular dose of aspirin can also increase the risk of bleeding stomach ulcers.
Importantly, 21 out of 36 studies included in the meta-analysis of aspirin and the three cancer types had no data on bleeding.
We appreciated the fairness of the release. In addition to highlighting the correlation in better survival with low-dose aspirin, it also called out its weaknesses. Those included a lack of important data (e.g. on bleeding) and a need for new, randomized trials to test their hypothesis.
We found the cause-and-effect language (“could increase survival”) used was inappropriate for a study whose conclusions are based almost entirely on observational studies.
The release also doesn’t make clear when the aspirin is to be used. Is it during active treatment of the cancer with chemotherapy? Is it after the primary treatment is provided? One could imagine concern with using aspirin in regimens associated with bone marrow suppressing effects. The implication is that this should be part of standard cancer treatment, but not enough information is provided to make it clear.
In reviewing the published study, there are comments about how it was hard to perform the analyses due to differences among studies. Given the statements in the release about patients using this evidence to decide on the role for using aspirin as part of cancer treatment, we think that that these additional details should be provided.
We didn’t see any evidence of stoking fears about disease; the language is grounded and straightforward.
Funding sources and potential conflicts of interest weren’t noted in the release. The study, published in PLoS ONE, however, declares no conflicts of interest and — curiously — no support or funding, either.
But since this type of study is based on analyzing others’ results, we’ll go out on a limb to assume that the researchers’ institutions backed it in the form of their usual salaries. In any case, we want to see these items clarified in news releases.
The alternative approach to going on a low-dose regimen of aspirin — i.e. not doing so — is assumed but not made clear. But we’ll award points to the release for smartly quoting one of the study authors on seeking out the advice of a doctor before taking aspirin regularly.
The release doesn’t address availability but we know aspirin is available in pretty much any convenience store on Earth. We’ll rate this “not applicable.”
The release makes an indirect claim of novelty by summarizing the research as an effort to look at “its role in the treatment of cancer.” The novelty of the work is pretty clear: Take a whole bunch of smaller studies and, through strength in numbers and careful analysis, see how low-dose aspirin might help or hinder cancer patients. And the number that emerges is impressive. While aspirin and other NSAIDs have been proposed for use in cancer prevention, especially colon cancer, use as a treatment for cancer itself is novel.
We didn’t see anything glaring in the body of the release. The headline: “Taking aspirin could increase cancer survival by 20 percent” captures attention but might have been more faithful to the study by making it clear than only a correlation was found between aspirin and lowered cancer risk.