It is a new year, and unfortunately, we can expect 2016 to bring more sensational breast cancer headlines. Think of some headlines we saw in 2015: Everyone over age 30 should be tested for the BRCA gene mutation. Olive oil may help prevent breast cancer. A virus found in cattle is linked to increased breast cancer risk. How do you know what is true, what is hype and what is misinformation?
It can be overwhelming to someone who has been diagnosed with breast cancer or for someone helping a loved one navigate the maze of information surrounding this disease. Conflicting messages, oversimplification of complex studies and just plain misinformation about causes, treatment, scientific breakthroughs and "miracle" medicines can be found far and wide.
The National Breast Cancer Coalition (NBCC) wants to help you cut through the breast cancer clutter by answering the crucial question, "How do I decide what to believe?"
What should I look for in a news story about a research study?
Your introduction to a research study will likely come from a headline, a newspaper article or a story you see on the evening news. Or you will find various blogs and other sources of information on the web. Many of these are summaries of the latest in health care research and can oftentimes sound dire or too good to be true. The truth usually lies somewhere in between.
HealthNewsReview, an online reviewer of health care intervention stories, has helpful criteria they use to evaluate the news. You can take some of their criteria into consideration: Does the article exaggerate the condition? Over-sell symptoms as diseases themselves? Does the article include the cost of a new intervention? Cite the harms of the intervention? Include perspectives from the other side?
Critically reading a news account or blog of a health care "breakthrough," "warning" or other research-related finding is an important first step. And remember, sometimes you are reading objective reporting and other times a subjective analysis. Learn to tell the difference.
Who is the expert?
It depends. It is important to understand who is giving the information you are considering. A medical doctor, even a breast cancer specialist, is not necessarily an expert in conducting research or in analyzing it. Looking at the news coverage of the various mammography screening guidelines is helpful to understanding how to answer this question.
Mammography screening is a screening tool for a healthy population--most women get mammograms at some point in their lives. Medical interventions, including mammograms, are based on scientific evidence. The strongest evidence about any intervention or procedure comes from randomized clinical trials. You might assume that an "expert" when it comes to mammograms is a radiologist because she or he is the doctor who reads your mammogram results. But your radiologist is most likely just an expert in evaluating an individual mammogram.
The experts in determining population-based public health interventions such as how often and at what age women should get mammograms are the public health scientists and doctors who design and analyze the evidence about mammograms to determine if they help prevent breast cancer deaths. They then set guidelines based on that evidence.
The process and type of experts involved in determining if a new drug is an effective treatment may be different. And sometimes there are conflicts of interest that should make you question the messaging. Is the information coming from an objective expert, such as the United States Preventive Services Task Force, or is it from a medical expert or group with a subjective stake in the matter, such as the American College of Radiology?
So, not every "doctor" is necessarily an "expert" in every aspect of breast cancer.
What is a good study?
When you read about a new, "scientific" study telling us that X, Y, or Z increases our cancer risk or helps prevent us from contracting a certain disease or is a breakthrough treatment, it is important to ask questions and seek more information before assuming it is true.
Is the study a human trial or animal study? Most preliminary or basic research studies are conducted using animal models. These are important basic science studies to complete, but the results may not translate into humans. Until human clinical trials are actually performed, animal studies remain preliminary reports of what might one day impact humans. It has been said many times that we often cure cancer in mice. But that cure has yet to translate to a human being.
What type of study is it? There are many forms of human studies with varying degrees of reliability. All research results are not equal. Anecdotes, or what happened to one or a few people, are not reliable because they are biased observations, which cannot then be generalized to others. A case report documents an unusual case or outcome from treatment--but again, the results could potentially not apply to others. An observational trial looks backwards to study a treatment or forward to observe who gets a disease or condition--this is better, but, for example, you cannot control all the factors that could contribute to the development of disease. Randomized clinical trials are the gold standard for testing a new drug or intervention. Because people are randomly assigned to experimental groups or a standard of care group, and most of the bias is controlled, we are more comfortable saying the results are true and applying them to others like those in the study.
How many people were in the study? An important question to ask is how many people were in the study? There have been occasions when results were touted as important breakthroughs and looking just a bit below the surface showed that those results were based on a study of 12 people.
How do I determine what's my actual risk?
Risk, as you all know, is the chance of something happening. In medical research, there is both absolute risk and relative risk. Absolute risk is the actual risk itself. Relative risk is comparing two risks--finding out which one is more likely compared to the other. Oftentimes, you will see relative risk reported because it is the flashier of the two. But absolute risk is most important.
Take the example of Tamoxifen, a popular breast cancer drug. It is often touted as reducing breast cancer risk--that is, in a healthy but high risk population (not the average woman)--by as much as 50%. Sounds fantastic, right?
The 50% number is the relative risk reduction from Tamoxifen in that study. Reported in terms of absolute risk, Tamoxifen use "prevented" clinically detectable breast cancer in only 2% (4.3 - 2.2) of the women who took Tamoxifen. And remember that while the study population was limited to women at high risk of getting breast cancer, these were healthy women. Thus, many healthy women received a drug that has risks associated with it and that benefited only a small percentage of the total study population. And there are many other questions the trial did not answer, such as whether it prevented deaths or at what age a woman would begin to take the drug.
So who--and what--should you believe? There are no easy answers. Approach the information you find with a critical eye. Do you want to really understand the language of science and how to be a critical reader of health information? Learn about NBCC's world-renowned Project LEAD® to get trained in the science of breast cancer. Or attend our Annual Leadership Summit to learn the latest in breast cancer research, better understand the information and gain leadership skills to advocate for better breast cancer policies.
The bottom line is that scientific studies are complicated. Be willing to ask critical questions, do your research, and at the minimum, be skeptical.