Suspicious citation numbers found in high-impact journals

The likely manipulation of citation numbers by research paper mills in high-impact cancer journals has been uncovered by an international team of researchers. Their findings, published in PNAS, point to an organised campaign to inflate citations on paper mill-produced journal articles published in established molecular oncology journals.

As explained by corresponding author Professor Adrian Barnett, from QUT, “Research paper mills are fraudulent organisations that produce and sell manuscripts and publishing services of faked research.

“Just as likes and shares indicate social media influencers’ audience engagement, citations from other researchers are an important academic measure for evaluating scientists’ research impact.

“Because citation counts are now a key measure of academic performance, they can incentivise journals and researchers to maximise citations counts.”

Paper mill papers are not genuine scientific contributions, Barnett emphasised, and so highly manipulated citation counts reflect artificial amplification rather than genuine scientific engagement.

“A danger is that artificially inflated citation counts may distort the evidence base by misinforming future research and clinical translation,” he said.

Co-researcher Baptiste Scancar, from L’Institut Agro in France, said the team evaluated the impact of paper mills on citation patterns in 33,159 articles published in 20 high-impact journals of molecular oncology between 2012 and 2023.

“Applying our previously developed detection model, we flagged a total of 4085 articles as potentially associated with paper mills, based on their textual similarity to the titles and abstracts of retracted paper mill articles,” Scancar said.

Suspected paper-mill articles received 50–100% more citations than non-flagged articles within one to three years of publication. However, flagged articles received fewer readers and online access counts compared with non-flagged articles.

“Having more citations but fewer readers makes no sense, as citations come from readers,” Scancar said.

Flagged articles disproportionately cited and were cited by other flagged articles and were clustered in journals known to be targets of paper mills — including the Journal of Experimental & Clinical Cancer Research and Molecular Cancer — whereas other journals were only marginally affected, Scancar claimed.

According to Barnett, the documented pattern suggests widespread, coordinated manipulation of citation counts by paper mills, which could inflate journal impact factors, amplify unreliable findings and slow scientific progress. The good news is, the team’s findings point to measurable signatures of citation manipulation that could support article- and journal-level screening.

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