By Diana Zuckerman, Ph.D. and Jennifer Focht
Everyone wants to find a cure for cancer, but some medical researchers are exaggerating the effectiveness of the treatments they study. In some cases, information about side effects and other risks are downplayed as well.
To find out if a treatment works, medical researchers compare patients who take the treatment to patients who take a different treatment, or take no treatment at all. The outcome that matters to patients is whether the treatment will cure them or at least help them live longer, with a better quality of life.
That isn’t always the outcome that scientists study, however. For example, a company may instead want to measure whether the treatment successfully got rid of cancer cells or slowed down the progression of cancer. These kinds of measures are called “surrogate endpoints” or “biomarkers” because they substitute for the outcome that really matters (health and survival) by evaluating things that can be studied more quickly and easily and are expected to be related to health and survival – but might not be. Unfortunately, in their desire to get more cancer treatments to market more quickly, many cancer drugs are approved by the FDA based on these preliminary kinds of findings, rather than based on improved health or survival. It may take years or even decades to find out if the new drugs really save lives or improve the quality of patients’ lives. Research published in 2015 indicates that the studies done after recent cancer drugs were approved were more likely to show they don’t save lives or improve health than to show that they do.1
For these and other reasons, published studies of cancer treatment can be misleading.
In addition to FDA lowering the standards for cancer drugs, there are other reasons why doctors and patients may not have all the information they need to help patients make the best treatment decisions. For example, medical journals prefer to publish articles about treatments that are effective, instead of treatments that are not. New, effective treatments are more exciting, but for patients, knowing which drugs don’t work well is just as important as knowing which ones are effective. If researchers learn that a treatment doesn’t actually work, they may have a very hard time getting the results published. And, if the research was funded by the company that makes the treatment, as it usually is, that company will probably not want the study to be published.
Even when researchers sincerely want to publish their study results to help patients, they may find that being completely honest about unimpressive or ambiguous results means they won’t get the study published. Publications are important to scientists, so what can they do to improve their chances of getting the study published in a major medical journal? Those researchers might find it easier to get the article published if they focus on the positive results (such as slowing down the spread of cancer) and ignore the negative results (for example, if the patients did not live longer because the toxic effects of the treatment caused them to die anyway).
Dr. Francisco Emilio Vera-Badillo and his colleagues at the University of Toronto reviewed published articles on breast cancer treatments and found that one out of three misrepresented a treatment’s overall ineffectiveness by highlighting some other benefit. For example, a study might show that patients’ quality of life improved slightly when they started the treatment in question. Feeling better is important, even if only for a short time – but it is a subjective measure that could be influenced by feeling hopeful about getting a new medication. If the purpose of the study was to determine whether or not the treatment helped patients live longer, or at least had a major health benefit from the treatment, then this secondary benefit that a few of the patients felt a little better is just that: secondary. Can a treatment be considered “effective” if it doesn’t do what it is supposed to do? Is it worth the potential risks to one’s health (most cancer drugs are highly toxic) and the costs (which may be tens of thousands of dollars) to take a drug that isn’t really effective? If the benefits of the new drug are very modest, there may be other, less dangerous and less expensive strategies that could help patients much more. And, even more important, in the same analysis, two out of three of the published articles described the results of their research in a way that glossed over negative side effects, especially when the treatment was effective.2 But negative side effects can be very harmful, or even deadly, so it is important that they be accurate reported.
A separate review of published articles on a variety of health treatments—not just cancer treatments—showed that 16% reported no data about side effects. In nearly one-third of the articles, information on side effects was reported inadequately.3 For example, when researchers found an increased risk of heart attack associated with the arthritis drug Vioxx, they changed the reported time frame of their study when they wrote up their results.4 As a result, the published article did not mention the participants who had experienced heart attacks during the last month of the trial and Vioxx seemed safer than it actually was. (When these risks became known, Vioxx was recalled in 2004.)
Information about a drug’s effectiveness and side effects are both important, and both should be reported in studies so that patients and their doctors have a full understanding of treatment options. In many areas of medicine, research tends to over-emphasize effectiveness and down-play side effects, and for cancer drugs this tendency may be even more pronounced. Many cancer researchers are calling for stricter guidelines, like standardizing reporting of results to make it more obvious when information is missing, but that will only address part of the problem.
In the meantime, what can you do to ensure the safety of the treatment you are receiving? If you have just been diagnosed with cancer, you may want to consider an older treatment over a newer one. Why? Because newer drugs are often approved on preliminary evidence and wishful thinking, and too often years pass before the true risks and benefits are known. In most cases, newer treatments haven’t been researched as thoroughly as older ones that have been sold for many years. If your doctor wants you to switch to a newer treatment, ask him or her to review each of the side effects with you and compare them to the side effects of your old treatment. If after starting a new treatment, you notice side effects—expected or unexpected—let your doctor know right away. Ask as many questions about your treatment as you want. There are no stupid questions—only stupid answers. You have the right to complete information on your treatment’s effectiveness and risks.
For information on the influence of industry funding on medical research, click here.
- Mulcahy, Nick. (October 2015). “Approved But Not Proven: What’s Up With FDA, Cancer Drugs?”. Medscape Medical News. 2015. http://www.medscape.com/viewarticle/853060 ▲
- Vera-Badillo, FE, Shapiro, R, Ocana, A, Amir, E, Tannock, IF. Bias in reporting of endpoints of efficacy and toxicity in randomized, clinical trials for women with breast cancer. Annals of Oncology. 2013; 00: 1-6. ▲
- Pitrou, I, Boutron, I, Ahmad, N, Ravaud, P. Reporting of safety results in published reports of randomized clinical trials. Archives of Internal Medicine. 2009; 169(19): 1756-1761. ▲
- Krumholz, HM, Ross, JS, Presler, AH, Egilman, DS. What have we learnt from Vioxx? BMJ. 2007; 334(7585): 120-123. ▲