It seems that nearly every day there’s an article somewhere about a “breakthrough” in cancer research or therapy, but we know that real breakthroughs remain elusive. When it comes to diet or lifestyle factors that may either increase or reduce risk for cancer, news reports contradict one another over and over again.
So how do we stay up to date on important developments? What are some strategies for making sense of the news we read on these subjects?
Let’s start with what we see first–the headlines. Besides the obvious effort to “sell” the news, headlines may severely distort or even contradict the real content of an article. Sometimes it’s an article worth reading, if not for the reasons suggested by the headline. An example of this is an article that appeared in TIME magazine in April 2013 with the cover title “How To Cure Cancer”, and a subtitle “Yes, it’s now possible, thanks to new cancer dream teams that are delivering better results faster.” Despite the absurdly exaggerated claim of the cover headline, the story did not in fact suggest that we now know how to cure cancer, but did provide an interesting discussion about trends in the way cancer research is conducted today.
It’s important to maintain a healthy degree of scepticism in reading any report that focuses on the findings of a single new research study, even in a well-respected scientific journal. Similarly, it’s a good idea to question any study that totally refutes the current state of knowledge on a subject. A single study looking at a particular hypothesis or potential new therapy is often contradicted by subsequent studies. A possible new therapy very often doesn’t pan out as research moves through the long journey from cell culture studies to animal models to early and later stage trials in humans.
In an article in the Columbia Journalism Review entitled “Survival of the wrongest”, David H. Freedman describes some of the numerous sources of bias inherent in scientific research and suggests that reporters have a responsibility to alert readers and to be more sceptical in their reporting. He writes:
When science journalism goes astray, the usual suspect is a failure to report accurately and thoroughly on research published in peer-reviewed journals. In other words, science journalists are supposed to stick to what well-credentialed scientists are actually saying in or about their published findings–the journalists merely need to find a way to express this information in terms that are understandable and interesting to readers and viewers.
But some of the most damagingly misleading articles don’t stem from the reporter’s failure to do this. Rather, science reporters–along with most everyone else–tend to confuse the findings of published science research with the closest thing we have to the truth. But as is widely acknowledged among scientists themselves, and especially within medical science, the findings of published studies are beset by a number of problems that tend to make them untrustworthy, or at least render them exaggerated or oversimplified.
Systematic reviews of the medical literature such as those prepared by the Cochrane Collaboration synthesize the results of numerous studies on a given medical research topic in a way that is intended to minimize bias. Systematic reviews help physicians to practice evidence-based medicine and can be a helpful resource for the current state of knowledge on a topic.
Keeping all of that in mind, here are five key things that I ask myself when I’m reading reports about new findings in cancer research:
1) How strong is the evidence in support of the new finding?
Is the new finding based on lab and animal studies only? If it’s a clinical trial, how large is the group of patients studied? Early phase clinical trials often include only small numbers of patients. These studies may result in findings that later are not replicated in the larger Phase III clinical trials that are necessary for approval of a new drug.
For studies of dietary or lifestyle risk reduction strategies, what type of study was conducted and how large was the study group? And, even if the study group was large, it’s important to remember that observational, population-based studies only point to associations between behaviors and risks. These studies may provide useful information that can be the basis for further studies or clinical trials, but they do not demonstrate cause and effect relationships.
2) What is the benefit of the new treatment or risk reduction strategy in absolute terms?
A report that describes the benefits of a new treatment or risk reduction strategy in terms of relative risk only, which is common, can give the impression that the treatment is more beneficial than it really is. It’s essential to know the starting point, or absolute risk level, that would be improved upon. For example, let’s say the risk for recurrence of disease without additional treatment is 5%. An article describes a new treatment that has been shown to reduce risk of recurrence by 50%. What that means is that the new treatment would reduce the risk of recurrence from 5% to 2.5%, a reduction in absolute risk of 2.5%.
3) What are the side effects associated with the new treatment?
Does the article address the types and likelihoods of possible adverse side effects of the new treatment? Writing in Huffington Post, Dr. Elaine Schattner discusses a report in Annals of Oncology about bias in scientific journal reports on breast cancer clinical trials. Scientific journal articles are an important source of information for reporters, and for doctors, about new treatment developments. Dr. Schattner comments that:
What’s noteworthy, or shocking — as in a wake-up call to journal editors — is the finding that two-thirds of the randomized, published clinical breast cancer studies didn’t adequately report on side effects….Details matter, and too often when I read about a new breast cancer drug I have to turn to, say, Table 4A, to learn of a new drug’s grade III effects on the gut or lungs. That takes effort, access to journals, and wanting to know.
4) How soon will the new treatment or other medical intervention be available?
If the report is about preclinical research in animal models, for example, any possible new therapy that could result is likely to be many years away. Positive findings in early stage clinical trials, as well, would still likely require years more of study in trials, followed by FDA approval if a new drug is involved, prior to becoming available in the clinic.
5) Will the new treatment or other medical intervention be affordable?
For new drug treatments or other medical interventions, another very important consideration is the cost of the treatment or procedure and whether it would be covered by health insurance, which directly impacts its accessibility. This is a critical issue that is often not mentioned in news reports.
If you’d like additional information on reading medical news reports with a critical eye, an excellent resource is the website Health News Review.org. A very helpful book on the subject is “Between the Lines: Finding the Truth in Medical Literature” by Marya Zilberberg MD, MPH.
Image courtesy of Salvatore Vuono / FreeDigitalPhotos.net