Approximately 1 in 4 lung cancer clinical trials registered on ClinicalTrials.gov before 2016 remain unpublished, according to a new study.1

This lack of publication raises a “concern of publication bias in the field of thoracic oncology,” according to the study researchers.

In this analysis, the researchers identified 1294 phase 2 or phase 3 clinical trials involving patients 18 years or older with recruitment status listed as completed (1038 trials; 80.2%) or terminated (256 trials; 19.8%).

Using a database search, the researchers found that 67.6% of trials had results published and 32.4% were unpublished. To examine this further, they sought contact information for trial investigators, which was found in 54.5% of the unpublished trials.

Of these responses from trial investigators (102 responses from investigators across 183 trials for which investigators could be located), 51 reported peer-reviewed publication of their trials and 51 confirmed that the data were not published.

In all, among completed trials included in this study, 72.5% (753 trials) of trials were published and 27.5% (285 trials) were not.

The researchers found that compared with industry-sponsored trials, trials sponsored by the National Institutes of Health (NIH) was more than twice as likely to be published (odds ratio, 2.27) and trials sponsored by academic institutions were 1.5 times (OR, 1.55) more likely to be published.

Additionally, trials with more than 500 patients enrolled were 3 times (OR, 3.43) more likely to be published compared with studies with fewer than 100 patients enrolled.

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Of the 256 trials listed as terminated on ClinicalTrials.gov, 71.9% remained unpublished.

“Timely publication of clinical trial findings is instrumental in informing oncology practice and future research. Also, the ethical standards set out in the Declaration of Helsinki obligate researchers to report the results of their work regardless of the results,” the researchers wrote. “Clinical trials rely on the willingness of patients to risk exposure to unproven interventions. Reporting trial results is our obligation and responsibility to trial participants.”

Disclosure: Dr Kim reported receiving grants from AstraZeneca, Novartis, Tesaro, Regeneron, and Karyopharm outside the submitted work. For a full list of disclosures, please refer to the original study.

Reference

Al-Shbool G, Latif H, Farid S, et al. Publication rate and characteristics of lung cancer clinical trials. JAMA Netw Open. 2019;2(11):e1914531. doi: 10.1001/jamanetworkopen.2019.14531