Guest-Edited Special Issues: The Peer Review Risks No One Warns Authors About

On April 14, 2026, BMJ Group announced the retraction of seven of eight papers from a guest-edited special issue of the Journal of Medical Genetics. The issue had been published in 2019 and focused on cancer immunotherapy. The investigation found that the guest editor had selected peer reviewers, most of whom were affiliated with Nanjing University in China, and that the peer review process had been irreparably compromised in nearly every article. The one surviving paper was a Harvard-affiliated breast cancer case report that apparently passed independent scrutiny. Everything else in the issue came down.

If you write in biomedical sciences and have received an invitation to contribute to a special issue in the past year or two, this story is about more than one journal. The Journal of Medical Genetics retraction is a specific and documented case, but the structural conditions that produced it are widespread and, if anything, better established now than they were in 2019. Understanding what went wrong there is useful preparation for any author evaluating a special issue invitation today.

Why Special Issues Became a Weak Link in Peer Review

A traditional peer review workflow has the journal's editorial office at its center. Editors with institutional accountability receive submissions, screen them against scope, assign reviewers from their own vetted pool, read the reviews, and make decisions. The reviewers are chosen to be independent of the authors, and the editorial staff has a direct stake in the journal's long-term reputation.

Guest-edited special issues often work differently. A guest editor, typically a respected researcher in a subfield, proposes a thematic collection, recruits contributors, and manages the review process for those submissions. At reputable journals with strong oversight, the guest editor is supervised, reviewer selections go through editorial approval, and the journal staff remains involved in decisions. At journals with weaker infrastructure, the guest editor effectively operates as a parallel editorial unit with limited accountability to the parent journal.

The problem is not the guest editor model in principle. The problem is when journals use it to expand output without expanding editorial capacity. Several independent analyses have found that special issues tend to have faster turnaround times, lower rejection rates, and less stringent reviewer independence checks than regular article channels at the same journal. When those conditions combine with a guest editor who has a conflict of interest, the peer review filter becomes extremely porous.

The Journal of Medical Genetics case is a clear example of how that failure looks in practice. The guest editor chose reviewers from their own institutional network. Whether that was deliberate manipulation or negligent familiarity is not fully established in the public record. But the structural opportunity for it to happen existed because the journal's oversight of reviewer selection was insufficient.

The Economics That Created the Incentive

To understand why special issues became so common, you need to follow the financial logic. Guest editors work without payment. They recruit contributors, often through personal networks, which reduces acquisition cost for the publisher. The contributors frequently pay article processing charges (APCs), which creates direct revenue. And because special issues tend to generate more submissions in a shorter window, publishers can accelerate their output numbers and the associated metrics.

From the researcher's side, a guest editorship offers an attractive CV line, the chance to build a thematic collection around one's own research agenda, and implicit authority over which papers appear alongside each other. That authority is precisely what bad actors have exploited: the guest editor can select reviewers sympathetic to affiliated authors, accept papers from their own group in excess of what would be editorially defensible, and shape a special issue into something that functions like a paper mill with academic branding.

Research published in 2024 in Taylor and Francis's journal on research ethics found that in roughly 13 percent of special issues produced by major publishers over the preceding decade, the guest editor had contributed more than one-third of the papers in the issue. That concentration would not pass editorial muster in a regular submission channel. In a guest-edited structure, it sometimes did.

Wiley and Hindawi had also announced waves of retractions in 2022 and early 2023 linked specifically to compromised peer review rings operating through special issues, with more than 1,700 papers retracted across those two rounds alone. The papers came from dozens of journals, suggesting the problem was not isolated to one bad actor but systemic to the model when oversight was thin.

What Honest Authors Risk When This Goes Wrong

The Journal of Medical Genetics case had one paper that was not retracted. The Harvard-affiliated breast cancer case report apparently survived because it had been reviewed independently and its integrity held up. But the authors of that one surviving paper still spent years with their work appearing in an issue that is now largely a retraction record. That reputational proximity is worth taking seriously.

Honest authors who publish in compromised special issues rarely get retracted themselves. But they do get associated with the story. Readers who search for papers on the topic will find the retraction notices alongside whatever remains. Grant committees and promotion committees sometimes ask authors to explain their publication record in detail, and a question like "why did you publish in that issue" is not one you want to answer under those conditions.

There is also a citation problem. When companion papers in a special issue get retracted, citations to those papers in your own work may later need to be flagged or corrected in post-publication notices. Retraction Watch documents these downstream effects regularly. The paperwork alone, before the reputational consideration, is genuinely costly.

Finally, some journals that have hosted compromised special issues have had their indexing status reviewed by Scopus or Web of Science in the aftermath. A journal that loses its indexing after you publish in it is a journal whose papers no longer appear in citation tracking. For early-career researchers whose funding or position security depends on citation metrics, that is a real risk.

Red Flags in Special Issue Invitations

Most special issue invitations arrive by email, often addressed generically, sometimes in strangely formal language, occasionally with spelling errors or oddly structured sentences. Not every awkward invitation is fraudulent, and not every polished invitation is legitimate. The invitation itself is just the starting point for a verification process, not a credential.

None of these patterns proves fraud on its own. An unsolicited invitation from a legitimate editor you have not met is normal in fields where editors actively search for contributors. A short deadline might reflect a conference supplement. But when three or four of these patterns appear together, the invitation deserves more careful scrutiny before you commit time to writing for it.

How to Verify a Special Issue Before Submitting

Verification is not complicated, but it requires going beyond the invitation email and the journal's homepage. Here is a practical sequence that most authors can complete in under an hour.

Start with the journal itself. Confirm it is indexed in Scopus, PubMed, or Web of Science by checking those databases directly rather than relying on badges displayed on the journal's own website. Then check whether the journal is a member of COPE (Committee on Publication Ethics), which maintains a public list. COPE membership does not guarantee integrity, but absence from the list at a journal claiming high editorial standards is a flag worth noting.

Next, look at the guest editor. Search for their publications, institutional affiliation, and whether they appear on the journal's editorial board or only in connection with this one issue. A researcher who can be found easily in PubMed or Google Scholar, who is genuinely active in the field the special issue covers, and who is affiliated with a real institution is not a guarantee of editorial integrity, but it distinguishes them from the constructed identities that have appeared in some compromised issues.

Then look at the journal's recent special issues. Browse the tables of contents. If multiple recent issues show one institution contributing a large proportion of the papers, particularly if the guest editor shares that institution, that warrants a closer look at the retraction history for those issues. Retraction Watch maintains a searchable database. Spending five minutes there before committing to a three-month writing project is reasonable precaution.

Finally, read the journal's author instructions for how it handles special issues specifically. Does the journal state that guest editor reviewer selections are subject to editorial board approval? Does it describe a blind review process for special issue papers comparable to regular submissions? Does it name any conflict of interest rules for guest editors, such as limits on self-authored papers within an issue? Journals that manage special issues well tend to describe that oversight explicitly. Journals that do not describe it may not have it.

Publisher-Level Differences Worth Knowing

Not all publishers handle guest-edited issues the same way, and the differences matter for submission decisions. Elsevier, Springer Nature, Wiley (after the Hindawi crisis), and Taylor and Francis have all tightened their oversight of guest-edited special issues in response to documented fraud. Each has published updated policies requiring editorial office involvement in reviewer selection, caps on the proportion of papers a guest editor can contribute, and stronger conflict of interest screening.

That tightening happened partly in response to external pressure. The retraction waves at Hindawi, the Chemistry World report on 50 journals being sanctioned by Clarivate over special issue concerns, and coverage in STAT News and Retraction Watch have collectively pushed publishers to treat this as a reputational risk, not just an editorial housekeeping issue. The Journal of Medical Genetics case in April 2026 is another forcing event.

At publishers where special issue oversight is documented and enforced, submitting to a guest-edited issue is not inherently riskier than submitting to a regular issue. The problem tends to cluster at journals that expanded output aggressively using the guest editor model without building the corresponding editorial infrastructure. Some of those journals are in well-known publisher families. The brand of the parent publisher does not automatically confer the oversight of the flagship title.

A Practical Decision Framework

When an invitation arrives, treat the first ten minutes as a triage decision, not a submission decision. Ask whether you can verify the journal, the guest editor, and the publisher's oversight policies in a short initial search. If yes, proceed to write. If something blocks verification, that is worth pausing on before you invest time in the paper.

For journals and guest editors you can verify, the next question is editorial alignment. Is your research genuinely within the stated scope of the special issue, or does the invitation feel more like a net cast broadly to fill pages? A well-run special issue will be editorially coherent: the papers in it will share a specific problem focus, cite each other where appropriate, and present a thread that the reader can follow. A poorly run issue will read like a random sample of papers that happen to include a keyword in their abstracts.

If everything checks out and the editorial coherence looks genuine, submitting to a special issue is a reasonable publication strategy. Themed collections can actually improve a paper's visibility, because readers browsing the issue encounter your work in the context of the field conversation you are trying to enter. The risk is not in special issues as a format. The risk is in special issues that have been disconnected from real editorial oversight.

One useful rule of thumb: if you could not explain who is reviewing your paper, who makes the final acceptance decision, and what would cause your paper to be rejected, the invitation has not given you enough information to submit confidently. A legitimate special issue should be able to answer all three of those questions somewhere in its call for papers or the journal's author guidelines.

What the April 2026 Retraction Actually Changes

The Journal of Medical Genetics retraction is not going to end guest-edited special issues. They are too financially and editorially convenient for publishers and guest editors alike. What it may accelerate is the adoption of stronger publisher-level standards for reviewer oversight in those issues, and a more skeptical posture from indexing bodies like Clarivate and Scopus when they evaluate journals that rely heavily on the model.

For individual authors, the most direct effect should be greater wariness when evaluating invitations. The Hindawi collapse was large enough that researchers who lived through it learned to be cautious about unfamiliar journals with high output. The BMJ Group incident involves a different kind of journal: an established, well-indexed, reputable title in a trusted publisher family. That is a harder lesson to absorb, because the usual shortcuts for identifying a safe venue (COPE membership, major publisher imprint, PubMed indexing) were all present and still did not prevent the problem.

The lesson is not to stop submitting to indexed journals in major publisher families. The lesson is that those signals screen for predatory journals, not for compromised special issues within legitimate ones. Special issue integrity requires a distinct layer of verification, specifically focused on the editorial oversight structure for that issue. That is the due diligence gap this case makes visible.

What Authors Can Reasonably Expect from Publishers Going Forward

Several publishers have announced or are implementing changes to how they manage guest-edited issues. The likely direction includes mandatory editorial office review of all guest-submitted reviewer suggestions, caps on how many papers from a single institution can appear in one issue, clearer conflict of interest declarations from guest editors at the time of issue proposal, and stronger post-publication monitoring for unusual citation patterns within special issues.

COPE has guidelines on special issues that include expectations for transparency about how reviewers are selected, how conflicts of interest are managed for guest editors, and what oversight the editor-in-chief retains over guest-edited content. If a journal's policies for special issues do not address at least these points, that is an observable gap you can flag before submitting.

The most practical thing authors can do with this information is add special issue verification to their standard submission checklist. It takes perhaps fifteen minutes per journal for the first time you submit to one, and creates a record you can reference if questions arise later. Researchers who treat that verification as standard practice are in a better position than those who rely on a journal's reputation alone, because the Journal of Medical Genetics case demonstrates that reputation and oversight are not always the same thing.

Further Reading