Looking For Published Cancer Trials? Fuggedaboutit
2 CommentsBy Ed Silverman // September 16th, 2008 // 10:26 am
Less than 20 percent of registered clinical trials of cancer meds are eventually published in medical journals, according to a reviewy published online today by the The Oncologist medical journal.
A search of the National Institutes of Health’s ClinicalTrials.gov web site identified 2,028 registered research studies of cancer treatments. Major medical journals, you may recall, require all studies considered for publication be registered at ClinicalTrials.gov or another publicly accessible database. And a subsequent search of the National Library of Medicine’s PubMed database showed that just 17.6 percent of the trials were eventually published in peer-reviewed medical journals.
The publication rate was particularly low for “industry-sponsored” studies, such as those funded by drugmakers - just 5.9 percent, compared to 59 percent for studies sponsored by collaborative research networks. Of published studies, nearly two-thirds had positive results in that the treatment worked as hoped. The remaining one-third had negative results - the outcome was disappointing or did not merit further consideration of the tested treatment, they report (look here).
The finding raises concern about publication bias in cancer treatment trials, according to the researchers, Scott Ramsey and John Scoggins of University of Washington and Fred Hutchinson Cancer Research Center in Seattle.
The researchers suspect the rate of negative results is much higher in the studies that have gone unpublished. “It is likely that many unpublished studies contain important information that could influence future research and present practice policy,” they wrote.
Of course, we know why a registered trial may not be published - some fail and a researcher may decide the result doesn’t enhance knowledge or one’s reputation. And some sponsors don’t want negative results out there. Same goes for some journal editors.
But “unpublished trials may have special importance in oncology, due to the toxicity and/or expense of many therapies,” they wrote. In other words, the knowledge base is incomplete. And who does that help?
A pair of accompanying editorials suggest some approaches to addressing the problem. One is from the National Cancer Institute’s James Doroshow, who writes about an effort to develop a database of administrative and outcomes data for all studies performed at NCI-supported institutions (here it is).
And The Oncologist editors write they are considering publication of a new, peer-reviewed, fully searchable venue for cancer treatment studies that would otherwise go unpublished (take a look).
Joana Ramos
Selective publishing of trial outcomes is also troubling in the face of the public recruitment campaigns around the globe by the clinical trials industry. Especially in the US, the take-home message for patients diagnosed with cancer is often that they will be both short-changing themselves and scientific progress if they do not enroll in a cancer trial. Trials may often be depicted, or perceived, as the only way to get the most cutting-edge i.e. effective treatment. Special recruitment marketing efforts are devoted to demographic groups that are minorities in the US, as well as to patients in specific other countries where CROs have set up shop. The US pitches emphasize that participation in trials is key to eliminating cancer health disparities. Along with patients, health care professionals, esp. nurses and social workers, are the specific
focus of trial recruiters. In many low- and middle-income countries, participation in trials might be the only way to receive hopefully effective treatment.
But almost no one wants to talk about the fact, except at the NIH Clinical Center or under other special circumstances,participation in cancer trials is limited to those who can pay for it, either via insurance or privately. Many cancer research centers, as well as community hospitals and outpatient community oncology practices, require upfront guarantee of payment as part of the screening process for admission to trials (as well as for standard care). The public funding behind many treatments in trials is likewise almost never mentioned.
With patient participation essential to trials, patients also need to be able to participate in trials if they so choose. And not to mention, to be able to find out about the outcomes of previous trials in order to make informed decisions about participation.
Gregory D. Pawelski
When an oncologist recommends a treatment the reason behind the recommendation may be complex. It can be a result of the doctor’s training and experience in combination with the investments made by the hospital or the doctors own research interests or their financial relationships with various outside entities.
In short, a patient and their family must be their own best advocate and get at the heart as to why a specific treatment regimen is being suggested. Don’t be afraid to ask questions to make informed treatment decisions!
Cancer sufferers are taking doses of expensive and potentially toxic treatments that are possibly well in excess of what they need. It would seem that pharmaceutical companies are attracted to studies looking at the maximum tolerated dose of any treatments. It is suggested by some that we make the search for minimum effective doses of these treatments one of the key goals of cancer research.
An increasing number of drug studies are developed through collaborations between academic medical centers and drug companies. In fact, pharmaceutical-industry investment in research exceeds the entire operating budget of the NIH. It is important to understand the influence that industry involvement may have on the nature and direction of cancer research. Studies backed by pharmaceutical companies were significantly more likely to report positive results.
Over the past couple of years, if you watched TV with any regularity, it would have been difficult to miss the direct to consumer advertising that touted the benefits of some drugs over others, especially for patients undergoing treatment for cancer. Even to the point that buses covered with “shrink wrapped” advertising being strategically placed outside major cancer centers for patients and their families to see (EPO anyone?).
Drugmakers are going directly to the consumer at a time when their products are indeed at the margins of evidence-based medicine. On one hand, pharmaceuticals advertise extensively and the advertising is manipulative in the extreme. On the other hand, even NCI-designated cancer centers do this sort of direct to consumer, hard sell advertising. And in cancer medicine, the media advertising is no more misleading than the one-on-one communication which often goes on between a chemotherapy candidate and an oncologist.
More must be spent on analyzing drug data, and the need for larger and more detailed studies to figure out why there is an association between pharmaceutical involvement and positive results.