Clinical trials are valuable in guiding evidence-based practice in medicine.1 Oncologists' decision-making regarding therapeutic regimens generally depends on information from publications in peer-reviewed journals, the main channel through which trial results are publicly disclosed and communicated.2 Thus, the reporting quality of publications is of vital importance to ensure accurate dissemination of evidence.3,4
ClinicalTrials.gov is the largest publicly accessible trial registry, and the only one with a results database.5,6 In September 2007, the FDA Amendments Act (FDAAA; section 801) was passed mandating the timely reporting of results of applicable clinical trials to ClinicalTrials.gov,7 which greatly expanded the legal requirements for the public reporting of trial results and enhanced reporting transparency. In contrast to peer-reviewed publications, which might be subject to the selective judgments of editors and reviewers, information posted on ClinicalTrials.gov goes through a quality assurance (QA) process when required information is missing or internally inconsistent.
Cancer is a major public health problem worldwide and is the leading and second-leading cause of death in China and the United States, respectively.8,9 The interpretation and accuracy of trial results are of particular concern in medical oncology, in which therapeutic regimens are often rapidly developed and prompt treatment decisions are important for saving lives. So how accurately does the published literature convey information to the oncologic community regarding the efficacy and safety of cancer drugs assessed in clinical trials?
Currently, only one study has investigated the reporting consistency between ClinicalTrials.gov result database and publications.10 However, trials included in the study were completed before January 1, 2009—2 years after the enactment of mandatory result reporting law—and only 5 trials (3%) related to oncology. The accuracy of published literature conveying information to the oncologic community on cancer drug trials remains unknown. Has reporting consistency improved in the 10 years since the mandatory reporting laws were enacted?
To address these questions, we included cancer drug trials with results posted on ClinicalTrials.gov and that were completed between 2004 and 2014. Our study had 2 objectives: to identify the degree of completeness and consistency of results reported between the ClinicalTrials.gov database and the subsequent publications, and to identify the trends of reporting quality and associated characteristics.
We would like to thank the staff members of the National Library of Medicine and NIH, and their colleagues across the United States, who have been involved with the development and maintenance of ClinicalTrials.gov. We thank the Clinical Trials Center, Sun Yat-sen University Cancer Center, for assistance in data interpretation.
The authors have disclosed that they have no financial interests, arrangements, affiliations, or commercial interests with the manufacturers of any products discussed in this article or their competitors.
This work was supported by grants from the National Natural Science Foundation of China (No. 81372409), the Science and Technology Project of Guangzhou City, China (No.132000507), the National Natural Science Foundation of China (No. 81402532), and the National Natural Science Foundation of China (No. 81572962).
See JNCCN.org for supplemental online content.
Chan AW, Altman DG. Identifying outcome reporting bias in randomised trials on PubMed: review of publications and survey of authors. BMJ 2005;330:753.
Food and Drug Administration Amendments Act of 2007. US Public Law. 2007:110–185. Washington, DC: Food and Drug Administration.
Chen W, Zheng R, Zeng H, Zhang S. The updated incidences and mortalities of major cancers in China, 2011. Chin J Cancer 2015;34:502–507.
Hartung DM, Zarin DA, Guise JM et al.. Reporting discrepancies between the ClinicalTrials.gov results database and peer-reviewed publications. Ann Intern Med 2014;160:477–483.
Patterson R, Nuttall JR. An evaluation of the risk of biopsy in squamous carcinoma: a clinical experiment. Am J Cancer 1939;37:64–68.
Common Terminology Criteria for Adverse Events (CTCAE), version 4.0. Available at: https://evs.nci.nih.gov/ftp1/CTCAE/CTCAE_4.03_2010-06-14_QuickReference_8.5x11.pdf. Accessed March 1, 2016.
National Cancer Institute. Summary Staging Guide, SEER Program. Bethesda, MD: National Institute of Health; 1981. NIH Publication No. 81.
Turner EH, Matthews AM, Linardatos E et al.. Selective publication of antidepressant trials and its influence on apparent efficacy. N Engl J Med 2008;358:252–260.
Wieseler B, Kerekes MF, Vervoelgyi V et al.. Impact of document type on reporting quality of clinical drug trials: a comparison of registry reports, clinical study reports, and journal publications. BMJ 2012;344:d8141.
Chan AW, Hrobjartsson A, Haahr MT et al.. Empirical evidence for selective reporting of outcomes in randomized trials: comparison of protocols to published articles. JAMA 2004;291:2457–2465.
Mathieu S, Boutron I, Moher D et al.. Comparison of registered and published primary outcomes in randomized controlled trials. JAMA 2009;302:977–984.
Riveros C, Dechartres A, Perrodeau E et al.. Timing and completeness of trial results posted at ClinicalTrials.gov and published in journals. PLoS Med 2013;10:e1001566; discussion e1001566.
Ioannidis JP, Lau J. Completeness of safety reporting in randomized trials: an evaluation of 7 medical areas. JAMA 2001;285:437–443.
Fu R, Selph S, McDonagh M et al.. Effectiveness and harms of recombinant human bone morphogenetic protein-2 in spine fusion: a systematic review and meta-analysis. Ann Intern Med 2013;158:890–902.
Carragee EJ, Hurwitz EL, Weiner BK. A critical review of recombinant human bone morphogenetic protein-2 trials in spinal surgery: emerging safety concerns and lessons learned. Spine J 2011;11:471–491.