Study: Some Cancer Clinical Trials Being Spun in a Positive Light at Meetings Despite Negative Results

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Study: Some Cancer Clinical Trials Being Spun in a Positive Light at Meetings Despite Negative Results

 

A recent study published in JAMA Oncology found that although about a third of cancer clinical trials failed to meet their primary endpoints, at oncology meetings they tend to be spun in a positive light. For example, in 91 negative cancer trials presented at the American Society of Clinical Oncology (ASCO) and European Society for Medical Oncology (ESMO) meetings, 29% of the presenters gave positive conclusions, typically focusing on positive subgroup data or some numerical advantage in the cohort receiving the drug.

“Presentations at medical meetings have great resonance within the scientific community, especially following the diffusion of social media,” wrote the authors, led by Massimo Di Maio of Ordine Mauriziano Hospital in Turin, Italy. “Oral presentations are not subject to peer review, and some authors’ conclusions may not be completely justified by the results.”

The study found that clinical trials run by nonprofit organizations were slightly more likely to do this, 30% compared to 26% by industry-sponsored trials. This has also been seen in cancer journal publications, “wrongly emphasizing borderline significance,” the authors stated.

It’s possible that commercial organizations may be concerned about the appearance of stock manipulation by putting a positive spin on things, although it’s also possible that the researchers do think there is value in presenting positive results for small populations in hopes of continuing further research in that direction.

About 50% of the time, the authors suggest a non-significant advantage in the drug arm of the trial was highlighted in the conclusions of studies, with a positive subgroup finding or secondary endpoint was emphasized in 46% and 38% of cases, respectively.

“Positive subgroup analysis of negative trials can be misleading, should not support treatment adoption, and, at best, should be hypothesis generating,” Di Maio and his colleagues wrote. “In some cases, however, such as the STAMPEDE trial testing prostate radiotherapy in patients with advanced prostate cancer, methodological strengths and weaknesses of the subgroup analysis were correctly discussed by the study presenter.”

The STAMPEDE trial was sponsored by the Medical Research Council, and evaluated novel approaches to treating prostate cancer.

The study found that about 27% of the time, researchers interpreted negative trial data post hoc as being noninferior.

“When a trial is designed to test the superiority of an experimental treatment, post hoc interpretation of noninferiority is methodologically debatable,” the authors wrote. “The noninferiority hypothesis should be prospectively planned, with a clear definition of the margin acceptable to define noninferiority.”

The researchers evaluated 208 oral presentations of Phase III clinical trials that were presented at the ASCO and ESMO trials from 2017 to 2019. They did not include noninferiority trials. The oral abstracts presented at ASCO in 2019, the authors cite, had more than 55% of negative trials spun to have some sort of non-negative conclusions. The worst year in general was 2019, with 47% of negative studies presented with non-negative conclusions, and the best year 2018 with 13%, followed by 2017 with 22%.

 

BioSpace source:

https://www.biospace.com/article/positive-spin-on-cancer-trial-presentations