Editorial Expressions of Concern: Science's Early Warning System

Introduction

Imagine you're reading a groundbreaking medical study that promises a new cancer treatment. The results seem perfect, and the scientific community celebrates the breakthrough. But then, months or even years later, you notice a formal note attached to the publication—an "Editorial Expression of Concern." What does this mean? Should you still trust the research?

These measured responses to scientific uncertainty represent publishing's self-correcting mechanism in action, balancing the need for timely information with the equal need for reliability. As these expressions have become increasingly common—with over 1,675 identified in one scientific database by 2023—understanding their role is essential for anyone engaging with scientific literature ⁷ .

The Guardian's Alert: What Is an Editorial Expression of Concern?

An Editorial Expression of Concern is essentially a publisher's note that flags potential issues with a published study without immediately retracting it. Think of it as a formal "yellow light" in scientific publishing—it doesn't stop traffic but warns everyone to proceed with caution.

The International Committee of Medical Journal Editors (ICMJE) formally introduced the term in 1997, and it was integrated into the National Library of Medicine system in 2004 ⁷ .

Unlike retractions, which definitively remove a paper from the credible scientific record, EEoCs are provisional communications that maintain the publication's status while an investigation is underway. They're sometimes called "Notices of Concern" or "Publisher's Notes," and they aim to draw readers' attention to possible problems with the validity of data, methodology, or results while stopping short of a final judgment ^{5 7} . This careful balance allows the scientific community to be informed about potential issues without pre-judging the outcome of an investigation.

When Science Sounds the Alarm: Why Expressions of Concern Are Issued

Journal editors don't issue Expressions of Concern lightly. The Committee on Publication Ethics (COPE)—an influential organization that guides journal editors—recommends EEoCs for very specific situations ^{2 5 7} :

What kind of problems typically trigger these concerns? Image duplication or manipulation is a common reason, appearing in approximately 40% of cases where EEoCs were issued ² . Other triggers include questions about data validity, methodological issues, potential plagiarism, or concerns about the interpretation of results that could affect the study's conclusions.

A Case Study: X-Ray Activated Cancer Vaccination

In March 2024, the journal Science Advances published an Editorial Expression of Concern regarding a promising 2020 research article titled "Nanoscale metal-organic frameworks for x-ray activated in situ cancer vaccination" by Ni and colleagues ¹ . This study had proposed an innovative approach to cancer treatment using nanoscale materials that could be activated by X-rays to stimulate anti-tumor immune responses.

The Concern

The concern emerged when the University of Chicago alerted the journal to apparent partial overlap between confocal images of two different control groups in the study's supplementary materials.

While confocal microscopy images are crucial for validating experimental results, duplication between control groups raises questions about whether the images were inappropriately reused or manipulated ¹ .

Rather than immediately retracting the paper, the editors chose to issue an Expression of Concern while the authors repeated the experiments for the supplementary figures in question. This approach balanced several important considerations: alerting the scientific community to potential issues, giving the original authors an opportunity to verify their work, and maintaining the published record pending the outcome of the reinvestigation. This case exemplifies how EEoCs serve as temporary measures during ongoing scientific scrutiny.

Behind the Scenes of a Concern: The Process and Key Players

The journey from initial concern to published notice follows a generally consistent pattern across scientific publishing, though specific procedures may vary between journals.

The Step-by-Step Process

The Authorship Question

Who actually writes and issues these notices? Practice varies between journals. Sometimes they're authored by the Editor-in-Chief, the handling editor, the entire editorial board, or occasionally the publisher itself ^{2 4 7} . This flexibility in authorship reflects the varying organizational structures of scientific journals but can also lead to inconsistencies in how concerns are expressed and handled across the publishing landscape.

The Data Behind the Concerns: A Growing Phenomenon

Although Editorial Expressions of Concern remain relatively rare in scientific publishing, their use has increased significantly in recent years. A comprehensive 2017 study published in Research Integrity and Peer Review identified 230 EEoCs affecting 300 publications in PubMed, with half of all EEoCs issued between 2014 and 2016 alone ² . This trend suggests growing awareness and use of this important mechanism for maintaining scientific integrity.

The outcomes of Expressions of Concern vary considerably. The same 2017 study found that by late 2016, only about 25% of publications with EEoCs had been retracted ² . A significant number of cases remained unresolved, highlighting that the process from concern to resolution can be lengthy and complex.

The Scientist's Toolkit: Key Research Reagents and Materials

In experimental sciences like the cancer vaccination study featured in our case study, specific research reagents and materials are fundamental to conducting the research. The table below details some key components mentioned in or related to the nanoscale metal-organic framework research that received an Expression of Concern.

Conclusion: The Evolving Landscape of Scientific Vigilance

Editorial Expressions of Concern represent an important evolution in scientific integrity mechanisms—a formalized way for the scientific community to say "we're looking into this" without rushing to judgment. While they create uncertainty and can be concerning for both authors and readers, they serve the crucial function of maintaining transparency in the scientific process.

The future of Expressions of Concern will likely involve continued refinement and standardization. Proposals have been made to make EEoCs more detailed and compliant with VACUP principles (verifiable, accurate, complete, updated, and public) ⁷ . Some have even suggested establishing "Author Expressions of Concern" where researchers themselves can formally raise concerns about the legitimacy of processes affecting their work ⁷ .

What remains clear is that as scientific publishing continues to evolve in scale and complexity, mechanisms like Editorial Expressions of Concern will play an increasingly vital role in helping the scientific community—and the public—navigate the sometimes uncertain path from initial discovery to established knowledge. They represent not a flaw in the scientific system, but rather its built-in capacity for self-correction and transparency—essential features of the scientific endeavor that ultimately strengthen our collective understanding of the natural world.