Letter to the editor

Retracting Inconclusive Research: Lessons from the Séralini GM Maize Feeding Study

In September 2012, Gilles-Eric Séralini and seven coauthors published an article in Food and Chemical Toxicology claiming that rats fed Roundup©-resistant genetically modified maize alone, genetically modified maize with Roundup©, or Roundup© for 2 years had a higher percentage of tumors and kidney and liver damage than normal controls. Shortly after this study was published, numerous scientists and several scientific organizations criticized the research as methodologically and ethically flawed. In January 2014, the journal retracted the article without the authors' consent on the grounds that the research was inconclusive. In June 2014, Environmental Sciences Europe published a slightly modified version of the retracted paper. The publication, retraction and subsequent republication of the Séralini study raise important scientific and ethical issues for journal editors. Decisions to retract an article should be made on the basis of well-established policies. Articles should be retracted only for serious errors that undermine the reliability of the data or results, or for serious ethical lapses, such as research misconduct or mistreatment of animal or human subjects. Inconclusiveness, by itself, is not a sufficient reason for retracting an article, though a flawed study design might be. Retracted articles that are submitted for republication should undergo scientific review to ensure that they meet appropriate standards. Republished articles should be linked to the original, retracted publication. Journals that are reviewing studies with significant scientific and social implications should take special care to ensure that peer review is rigorous and fair.

Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies

Abstract Glyphosate, an herbicidal derivative of the amino acid glycine, was introduced to agriculture in the 1970s. Glyphosate targets and blocks a plant metabolic pathway not found in animals, the shikimate pathway, required for the synthesis of aromatic amino acids in plants. After almost forty years of commercial use, and multiple regulatory approvals including toxicology evaluations, literature reviews, and numerous human health risk assessments, the clear and consistent conclusions are that glyphosate is of low toxicological concern, and no concerns exist with respect to glyphosate use and cancer in humans. This manuscript discusses the basis for these conclusions. Most toxicological studies informing regulatory evaluations are of commercial interest and are proprietary in nature. Given the widespread attention to this molecule, the authors gained access to carcinogenicity data submitted to regulatory agencies and present overviews of each study, followed by a weight of evidence evaluation of tumor incidence data. Fourteen carcinogenicity studies (nine rat and five mouse) are evaluated for their individual reliability, and select neoplasms are identified for further evaluation across the data base. The original tumor incidence data from study reports are presented in the online data supplement. There was no evidence of a carcinogenic effect related to glyphosate treatment. The lack of a plausible mechanism, along with published epidemiology studies, which fail to demonstrate clear, statistically significant, unbiased and non-confounded associations between glyphosate and cancer of any single etiology, and a compelling weight of evidence, support the conclusion that glyphosate does not present concern with respect to carcinogenic potential in humans.

Conflicts of interests, confidentiality and censorship in health risk assessment: the example of an herbicide and a GMO

We have studied the long-term toxicity of a Roundup-tolerant GM maize (NK603) and a whole Roundup pesticide formulation at environmentally relevant levels from 0.1 ppb. Our study was first published in Food and Chemical Toxicology (FCT) on 19 September, 2012. The first wave of criticisms arrived within a week, mostly from plant biologists without experience in toxicology. We answered all these criticisms. The debate then encompassed scientific arguments and a wave of ad hominem and potentially libellous comments appeared in different journals by authors having serious yet undisclosed conflicts of interests. At the same time, FCT acquired as its new assistant editor for biotechnology a former employee of Monsanto after he sent a letter to FCT to complain about our study. This is in particular why FCT asked for a post-hoc analysis of our raw data. On 19 November, 2013, the editor-in-chief requested the retraction of our study while recognizing that the data were not incorrect and that there was no misconduct and no fraud or intentional misinterpretation in our complete raw data - an unusual or even unprecedented action in scientific publishing. The editor argued that no conclusions could be drawn because we studied 10 rats per group over 2 years, because they were Sprague Dawley rats, and because the data were inconclusive on cancer. Yet this was known at the time of submission of our study. Our study was however never attended to be a carcinogenicity study. We never used the word 'cancer' in our paper. The present opinion is a summary of the debate resulting in this retraction, as it is a historic example of conflicts of interest in the scientific assessments of products commercialized worldwide. We also show that the decision to retract cannot be rationalized on any discernible scientific or ethical grounds. Censorship of research into health risks undermines the value and the credibility of science; thus, we republish our paper.