Concern Raised about 'Cancer Publication Bias'
DURHAM, N.C., Sept. 15 /PRNewswire/ -- Less than 20 percent of registered clinical trials of cancer treatment are eventually published in medical journals, according to a study published online today by the journal "The Oncologist."
Drs. Scott Ramsey and John Scoggins of University of Washington and Fred Hutchinson Cancer Research Center, Seattle, searched the National Institutes of Health's ClinicalTrials.gov registry to identify 2,028 registered research studies of cancer treatment. Major medical journals now require that all studies considered for publication be registered in a publicly accessible database like ClinicalTrials.gov .
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. "We find that less than 1 in 5 completed trials registered since the inception of ClinicalTrials.gov are listed in the registry or PubMed as published manuscripts," Drs. Ramsey and Scoggins write.
The publication rate was particularly low for "industry-sponsored" studies, such as those funded by pharmaceutical companies -- just 5.9 percent, compared to 59 percent for studies sponsored by collaborative research networks.
Of published studies, nearly two-thirds had "positive" results-the study 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.
This finding raises concern about "publication bias" in cancer treatment trials. The researchers suspect that the rate of negative results is much higher in the studies that have gone unpublished. Drs. Ramsey and Scoggins write, "It is likely that many unpublished studies contain important information that could influence future research and present practice policy."
There are several reasons why registered trials may not be published. Some trials may fail to meet recruitment or follow-up goals. If the trial is completed and the results are negative, researchers may feel that negative studies do little to advance scientific understanding, or to enhance their professional reputation. Sponsors may not encourage researchers to publish negative results. For their part, medical journal editors may be less enthusiastic about negative studies.
However, publication of negative studies is important for several reasons -- not only to avoid repeating negative trials, but also for what can be learned from the lack of response. "Unpublished trials may have special importance in oncology, due to the toxicity and/or expense of many therapies," the researchers add. The fact that so much cancer research goes unpublished raises concerns about the completeness of available information on present and future cancer treatments.
A pair of accompanying editorials comment on the underpublication of cancer treatment studies, and suggest some approaches to addressing the problem. Dr. James H. Doroshow of the National Cancer Institute (NCI) reports on efforts to develop a database of administrative and outcomes data for all studies performed at NCI-supported institutions.
Drs. Gregory A. Curt and Bruce A. Chabner, Senior Editor and Editor-in-Chief of "The Oncologist," echo the call for increased NCI involvement in ensuring publication of funded studies. Meanwhile, the editors of "The Oncologist" are considering publication of a new, peer-reviewed, fully searchable venue for cancer treatment studies that would otherwise go unpublished. "There is a need for a new venue for publishing all well-executed trials that fail to meet positive endpoints: 'negative' in a sense, but valuable nonetheless," Dr. Curt comments.
The article entitled "Practicing on the Tip of an Information Iceberg? Evidence of Underpublication of Registered Clinical Trials in Oncology," and the accompanying editorials, to be published in the September issue of "The Oncologist," are freely available online at:
(article by Drs. Ramsey and Scoggins);
(editorial by Drs. Curt and Chabner);
(commentary by Dr. Doroshow).
About AlphaMed Press
AlphaMed Press publishes the internationally renowned journals, "Stem Cells" and "The Oncologist." "Stem Cells," now in its 26th year, is the oldest and one of the world's top-tier peer-reviewed monthly journals in the fast-paced area of stem cells and regenerative medicine. "The Oncologist," in its 13th year, is a premier peer-reviewed monthly journal dedicated to physicians entrusted with the care of cancer patients. View AlphaMed Press journals at http://www.alphamedpress.org.
Contact: Dr. Martin J. Murphy, Executive Editor: 919.402.8750, Martin.Murphy@TheOncologist.com
|SOURCE AlphaMed Press|
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