A news release from the University of Texas MD Anderson Cancer Center describes a journal article about a study that found patients with epithelial ovarian cancer (EOC), the most common form of ovarian cancer, had better overall survival times if they were taking beta-blockers — a fairly common medication used to reduce blood pressure. However, the study doesn’t seem to support the sweeping claim of the news release headline that the heart medication was “shown to prolong ovarian cancer patients’ survival.” There’s no mention of any of the limitations of the study design or the potential harms associated with the use of beta blockers. Our review details these concerns and provides some suggestions for improvement.
[Editor’s note: we also looked at Wall Street Journal story about this study to see if the problems we found in the release were evident in the story. Our review has the details.]
Ovarian cancer is the eighth most common cancer for women in the United States, and is diagnosed in approximately 20,000 women each year. It is responsible for about 14,000 deaths each year. It is, in short, all too common and can be all too deadly. Evidence that a drug already on the market could prolong life for EOC patients is certainly worth reporting. However, it’s important to clearly define the limitations of that evidence. In matters of life and death, patients and their families are often willing to grasp at straws. Hope is a precious commodity, and it is important that EOC patients and their families not be given false hope. Misleading news releases can lead to misleading media coverage, and research institutions need to be sure they are writing about research findings responsibly.
The release doesn’t mention cost at all. Beta-blockers are currently available, and a monthly prescription can run patients from 10 to hundreds of dollars. The non-selective beta-blockers mentioned in the release are all available as a generic product and are relatively inexpensive as compared to the selective agents
The news release provides an understandable summary of the benefits seen in this retrospective review. “The release reports that EOC patients nonselective beta antagonists (NSBBs — a type of beta blocker) had a median overall survival of of 94.9 months. That’s compared to 42 months for EOC patients who did not take beta blockers, and 38 months for those receiving beta-1-adrenergic receptor selective agents (SBBs — another type of beta blocker).” But we think a few words about a couple of important provisos which we comment on under Quality of evidence should have been included.
The release doesn’t address harms at all. Side effects can range from diarrhea to depression, may trigger asthma attacks in asthmatic patients, and can cause complications for patients with diabetes. Some of these side effects may seem relatively inconsequential when compared to EOC mortality, but they’re worth mentioning.
The release does a fair job of describing the study — but fails to make clear what that study design means in terms of its limitations. For example, in addition to its very bold headline claim, the first sentence of the release states that researchers have demonstrated a benefit in overall survival among EOC patients receiving beta-blockers. Most readers would draw the conclusion that the study has found a clear cause-and-effect relationship between the use of beta blockers and prolonged survival in EOC patients. Not so fast. As the release itself makes clear, further down, some beta blockers — the SBBs — actually were associated with decreased survival. And even for NSBBs, what was found was a correlation, not clear evidence that the NSBBs were responsible for the prolonged survival. For one thing, the cohort of EOC patients who had taken NSBBs was only 76 people. Not a huge sample size. And as is noted in the paper, those who were treated with non-selective beta blockers had a smaller body mass index and had a higher percentage of “optimal cytoreduction.” Both have been show to improre survival. As the related journal article notes, “The current study is limited by its retrospective design and the resulting inability to document the duration of beta-blocker use and dosages used by patients with EOC.” The paper also points to two ongoing clinical trials incorporating both conventional chemotherapy and beta blockers, the results of which will inform the development of future “adequately powered, prospective, randomized clinical trials to determine whether NSBBs can improve outcomes for patients with EOC.” In other words, the paper itself makes clear that, while the use of NSBBs in EOC treatment is worth additional research, we don’t yet know whether beta blockers actually prolong EOC patients’ survival.
No disease mongering here.
The release includes an exhaustive list of funding sources and notes that one of the journal article’s co-authors has received funding from two pharmaceutical companies.
The relevant research is based on evaluating the use of beta blockers in conjunction with conventional chemotherapy, not as an alternative to chemotherapy or other courses of treatment. As such, we’ll rate “Compare Alternatives” as not applicable.
This is a close one. Yes, the release notes that beta blockers are already in widespread use. Yes, the release mentions the two ongoing clinical trials and how they’ll be used to design additional clinical trials. But the information on clinical trials is in the penultimate paragraph and the ramifications aren’t necessarily clear to lay readers — it will be years before researchers can determine whether beta blockers should be incorporated into clinical treatment of EOC patients.
Several previous studies have examined the impact of beta blocker use on EOC patients, and did not find the same prolonged survival rates that are reported on in this release. The journal article addresses this by noting that those studies did not appear to distinguish between SBBs and NSBBs — and that the different modes of action for those drugs has a significant impact on how they affect EOC patients during treatment. But the idea of evaluating the impact of beta blockers on EOC treatment is neither new nor limited to the researchers at MD Anderson.
The headline and lead paragraph reach further than the journal article can support. The rest of the release is much better, but it’s hard to make up for a misleading first impression.