When journals discover duplicated material, many choose to retract — but a cancer journal recently faced with the same dilemma involving a researcher with multiple retractions under his belt has instead decided to flag the paper with an expression of concern.
An editor told us that Cancers considered retracting the paper, by gynecologic cancer researcher Noriyuki Takai, but decided not to because the paper
contains some novel content that is of interest to the scientific community.
“Epigenetic Therapy in Human Choriocarcinoma,” published in 2010, has been cited once, according to Thomson Reuters Web of Science, and self-plagiarizes from other publications by Takai and his co-author, Hisashi Narahara. Both are researchers at Oita University in Japan.
Here’s the expression of concern:
We wish to make readers aware that text in  has been taken from other publications by the same author. In particular, much of Section 1, the first part of Section 2 and the first sentence of Section 3 are copied verbatim from . Table 1 and the second part of Section 2 are taken from . The main novel contribution of  lies in Section 3. We regret that these issues were not picked up before publication and wish to apologize to readers of Cancers.
Martyn Rittman, the chief production editor for MDPI, which publishes the journal, told us how the issue came to light:
It was reported to us by a reader and dates back to a time when we were not regularly using anti-plagiarism software for submissions.
Rittman told us why MDPI did not retract the paper, a review about therapies that target epigenetic changes in choriocarcinomas:
We considered this a borderline case, but our final decision was not to retract the paper. The paper contains self-plagiarized text, was published 6 years ago, and importantly contains some novel content that is of interest to the scientific community. The purpose of a retraction is to remove content from the literature, and on balance we decided it wasn’t the correct course of action in this case. We do consider self-plagiarism a serious issue, which is why we felt it necessary to make readers aware of the problems in this paper. Since self-plagiarism doesn’t involve presenting someone else’s work as your own it differs from other kinds of plagiarism, however it still raises problems of redundant publication and copyright infringement.
The decision to publish an Expression of Concern was made with the approval of the Editor-in-Chief, Prof. Samuel Mok, who recently joined the journal and was not involved in the peer-review of the original paper. MDPI is a member of COPE and takes publication ethics very seriously.
With 13 retractions, Takai currently holds the number 29 position on our leaderboard. He shares 11 retractions with Narahara, nearly all of which attribute the problems to errors in figures that were prepared by Takai. We’ve reached out to both researchers for more information, and we’ll update this post with anything else we learn.
Like Retraction Watch? Consider making a tax-deductible contribution to support our growth. You can also follow us on Twitter, like us on Facebook, add us to your RSS reader, sign up on our homepage for an email every time there’s a new post, or subscribe to our new daily digest. Click here to review our Comments Policy. For a sneak peek at what we’re working on, click here.