Scientists at a prominent cancer lab at Columbia University retracted four studies and a stern note was added to a fifth that accused it of “serious abuse of the scientific publication system,” the latest result of allegations of research misconduct recently leveled against several top cancer scientists. .
A scientific researcher in Britain last year uncovered discrepancies in data published by the Columbia lab, including the reuse of photographs and other images in various documents. The New York Times reported last month that a medical journal in 2022 quietly retracted a stomach cancer study by researchers after an internal investigation by the journal found ethics violations.
Despite the removal of that study, the researchers — Dr. Sam Yoon, head of a division of cancer surgery at Columbia University Medical Center and Changhwan Yoon, a more junior biologist there — continued to publish studies with questionable data. Since 2008, the two scientists have collaborated with other researchers on 26 papers that the whistleblower, Sholto David, publicly flagged for misrepresenting the results of the experiments.
One of those articles was retracted last month after The Times asked the editors about the allegations. In recent weeks, medical journals retracted three additional studies that described new strategies for treating stomach, head and neck cancer. Other labs had cited the articles in about 90 papers.
A major scientific publisher also attached a blunt note to the article it had initially removed without explanation in 2022. “This reuse (and in part, falsification) of data without proper attribution represents a serious abuse of the scientific publishing system.” he said.
However, these measures affected only a small fraction of the lab’s suspect documents. Experts said the episode demonstrated not only the extent of unreliable research by top labs, but also the tendency of scientific publishers to respond slowly, if at all, to major problems once they are identified. As a result, other labs continue to rely on dubious work as they funnel federal research money into studies, allowing errors to accumulate in the scientific record.
“For every one paper that gets retracted, there are probably 10 that should,” said Dr. Ivan Oransky, co-founder of Retraction Watch, which maintains a database of more than 47,000 retracted studies. “Journals are not particularly interested in correcting the record.”
Columbia Medical Center declined to comment on the allegations facing Dr. Yoon. It said the two scientists remained at Columbia and the hospital “is fully committed to upholding the highest ethical standards and strictly maintaining the integrity of our research.”
The lab website was recently taken offline. Columbia declined to say why. Neither did Dr. Yoon nor Changhwan Yoon could be reached for comment. (They are not related.)
Memorial Sloan Kettering Cancer Center, where the scientists worked when much of the research was done, is investigating their work.
The Columbia scientists’ retractions come amid growing attention to questionable data based on some medical research. Since the end of February, medical journals have retracted seven papers by scientists at Harvard’s Dana-Farber Cancer Institute. This followed investigations into data problems made public by Dr David, an independent molecular biologist who looks for anomalies in published images of cells, tumors and mice, sometimes with the help of artificial intelligence software.
The spate of misconduct allegations has drawn attention to the pressures placed on academic scientists—even those like Dr. Yoon, who also work as doctors — produce reams of research.
These studies often require robust images of experimental results. Their publication helps scientists win prestigious academic appointments and attract federal research grants that can pay dividends for themselves and their universities.
Dr. Yoon, an expert in robotic surgery noted for treating stomach cancer, has helped bring in nearly $5 million in federal research money over the course of his career.
The latest retractions from his lab included articles from 2020 and 2021 that Dr. David said contained blatant irregularities. Their results appeared to include identical images of tumor-bearing mice, despite the mice supposedly undergoing different experiments involving separate treatments and types of cancer cells.
The medical journal Cell Death & Disease retracted two of the latest studies, and Oncogene retracted the third. The journals found that the studies had also reused other images, such as identical images of constellations of cancer cells.
The studies that Dr. David pointed out as having imaging problems were largely overseen by the more senior Dr. Yoon. Changhwan Yoon, an associate research scientist who has worked alongside Drs. Yoon for a decade, was often the first author, which generally designates the scientist who conducted most of the experiments.
Kun Huang, a scientist in China who oversaw one of the recently retracted studies, a 2020 paper that did not include the more senior Dr. Yoon, attributed the problematic portions of this study to Changhwan Yoon. Dr. Huang, who made the comments this month on PubPeer, a website where scientists post about studies, did not respond to an email seeking comment.
But the most senior Dr. Yoon has long been aware of problems in the research he published with Changhwan Yoon: The two scientists were notified in January 2022 of the removal of their stomach cancer study that was found to violate ethics guidelines.
Research misconduct is often associated with more junior researchers conducting experiments. Other scientists, however, place more responsibility on senior researchers who run labs and oversee studies, even as they juggle jobs as doctors or administrators.
“The research world is realizing that with great power comes great responsibility, and in fact, you are responsible not only for what one of your direct reports did in the lab, but also for the environment you create,” Dr. Oransky said.
In the latest public retraction announcements, medical journals said they had lost faith in the results and conclusions. Imaging experts said some of the irregularities Dr. David bore signs of deliberate manipulation, such as flipped or rotated images, while others could have been sloppy copy-and-paste errors.
A journal’s little-noticed removal of the stomach cancer study in January 2022 underscored the policy of some scientific publishers not to disclose reasons for retracting papers as long as they have not yet formally appeared in print. This study had only appeared online.
Roland Herzog, the editor of the journal Molecular Therapy, said the editors had drafted an explanation they intended to publish at the time of the article’s removal. But Elsevier, the journal’s parent publisher, advised them that such a memo was unnecessary, he said.
It was only after the Times article last month that Elsevier agreed to publicly explain its removal of the strongly worded article. In an editorial this week, the editors of Molecular Therapy said that in the future they would explain the removal of any articles that had been published online only.
However, Elsevier said in a statement that it did not consider the online articles “to be the final published articles in history”. As a result, company policy continues to advise that such articles should be removed without explanation when found to contain issues. The company said it allowed editors to provide additional information where appropriate.
Elsevier, which publishes nearly 3,000 journals and generates billions of dollars in annual revenue, has long been criticized for its opaque removals of online articles.
Articles by the Columbia scientists with data discrepancies that remain unclear were widely distributed by three major publishers: Elsevier, Springer Nature and the American Association for Cancer Research. Dr. David alerted several journals to the data discrepancies in October.
Each publisher said it was investigating the concerns. Springer Nature said investigations take time because they can involve consulting experts, waiting for authors’ responses and analyzing raw data.
Dr. David has also raised concerns about independently published studies by scientists who collaborated with the Columbia researchers on some of their recently retracted papers. For example, Sandra Ryeom, an associate professor of surgery at Columbia, published an article in 2003 while at Harvard that Dr. David said contained a double picture. As of 2021, she was married to senior Dr. Yoon, according to a mortgage document from that year.
The paper had an official notice attached last week saying “appropriate editorial action will be taken” once data concerns are resolved. Dr. Ryeom did not respond to an email seeking comment.
Columbia sought to reinforce the importance of good research practices. Hours after the Times article appeared last month, Dr. Michael Shelanski, the medical school’s senior associate dean for research, sent an email to faculty members titled “Research Fraud Categories — How to Protect Yourself ». He warned that such allegations, regardless of their merit, could affect the university.
“In the months it can take to investigate an allegation,” Dr. Shelanski wrote, “funding can be suspended and donors can feel their trust has been betrayed.”
