More than 40% of journal papers about cancer trials are now being written by commercial medical writers rather than researchers, according to a new study that raises concerns the practice could result in conflicts of interest.

The study found the use of professional medical writers (PMWs) – also known as ‘ghostwriters’ – was especially common for industry-sponsored trials, and in studies that led to subsequent FDA approvals of oncology drugs.

The US and German researchers examined clinical trial registry data on 600 oncologic phase III randomised controlled trials conducted between 2003 and 2018 that had published primary endpoint results.

They examined the published papers to identify disclosures about the use of professional assistance in writing the manuscript – a disclosure that is required by some, but not all medical journals.

In all, 260 (43.3%) of the 600 papers disclosed that they had used a professional medical writer – “strikingly higher” than a 2006 report which found writing assistance was used in just 6% of publications, they wrote.

The study found 54% of industry-funded trials used PMWs compared with 3% of non-industry trials, that there was more likely to be writer assistance in trials that successfully met primary endpoints (53% vs 33%) and for those studies that led to subsequent FDA approvals (63% vs 36%).

Writing in The Oncologist, the authors said the figures may underestimate the true extent of PMW use because disclosure of writer assistance was still not universally mandated.

In almost all the trials that used ghostwriters (95%), the industry sponsor provided the writer with financial support, and the authors said there were concerns about potential conflicts of interest when papers were written by PMWs.

“Although prior data suggest that the use of PMWs may improve manuscript quality, others have raised concerns that PMWs may have a disproportionate effect in shaping the conclusions in industry-sponsored trials and therefore sway acceptance of trial data,” they wrote.

Distinguished cancer researcher Professor Stephen Ackland, Conjoint Professor in the School of Medicine and Public Health, University of Newcastle, said the increasing use of ghostwriters for oncology papers was a global phenomenon.

“I think it is an ever-increasing trend,” he said, adding that the rate of 6% cited from 2006 was likely an underestimate.

He said the use of PMWs was concerning because the way the data was interpreted may be biased in favour of the study sponsor.

Industry sponsors often used PMWs rather than waiting for busy clinicians to write research papers in order to expedite the publication of findings, in a bid to get their drugs to market more quickly, he said.

“Certainly when a sponsor is involved, they want the study published as quickly as possible because that’s how they make money.”

Professor Ackland, who is Editor-in-Chief of the Asia-Pacific Journal of Clinical Oncology, said PMWs were more commonly used when authors were from countries where English wasn’t the first language. The study showed that was the case, with PMWs used in 59% of trials where the first author was from an institute in a non-English speaking country compared with 34% in English speaking country first authors.

Transparency around use of PMWs could be enhanced by extending guidelines such as the International Committee of Medical Journal Editors (ICMJE) guidelines for medical journals, which state that non-author contributors should be acknowledged, Professor Ackland suggested.

He said oncologists and others reading papers on clinical trials also needed to consider whether a ghostwriter was used.

“It really behoves the reader to be aware this is happening …. and to consider it when appraising the value of the research.”

He also suggested all researchers should take responsibility for scientific communication of their findings.

“I think everybody should participate in the publication of their research, particularly of clinical trials,” he said. “I think there is a dereliction of that responsibility by some triallists to have involvement in the publication – if they let PMWs do it, they can put their own spin on it.”