Frankincense extract paper is 30th retracted by former MD Anderson researcher who once threatened to sue Retraction Watch

A cancer researcher in Texas who once threatened to sue Retraction Watch is up to 30 retractions, the latest involving a 2011 article which earned a correction the following year. 

The paper, “Boswellic Acid Suppresses Growth and Metastasis of Human Pancreatic Tumors in an Orthotopic Nude Mouse Model through Modulation of Multiple Targets,” came from the lab of Baharat Aggarwal, formerly of the University of Texas MD Anderson Cancer Center, in Houston.  

The paper, which was corrected in 2012, has received 50 citations, according to Clarivate’s Web of Science, all of which came after the correction. The latest of these references appears to be a recent preprint claiming to find that frankincense extract helps treat breast cancer. 

Per the retraction notice: 

After this article [1] was published, concerns were raised about the mouse tumor sizes reported in Figure 2. Specifically:

— The chart in Figure 2B of the article [1] reports tumour sizes of up to 5500 Photons/cm2/sec/steradian, with a standard error of approximately 1500 Photons/cm2/sec/steradian.

— The chart in Figure 2D of the article [1] reports tumour sizes of up to 23 cm3, with a standard error of approximately 6 cm3.

The journal asked the corresponding author to provide the individual-level data underlying these results and information about humane endpoints and health monitoring during the tumour experiments. In response, the corresponding author stated that they no longer have access to the data or the requested information.

PLOS ONE Editors consulted an expert in animal welfare and animal research methodology about this case. The expert assessed the article and noted that since these tumours are implanted orthotopically and not subcutaneously, typical tumour size limits for subcutaneous humane endpoints do not apply. However, they also stated that weekly monitoring of tumour volume as reported in the article would not have met U.S. standards for mouse tumour studies.

A representative of the Institutional Animal Care and Use Committee (IACUC) at The University of Texas MD Anderson Cancer Center also reviewed this paper in comparison to the animal research protocol approved by the IACUC in 2009 for this study (10-05-11032). They stated that what is reported in the article [1] is not in compliance with the approved IACUC protocol. The IACUC therefore recommended retraction of the article.

In light of the above concerns and the information received from the IACUC representative, PLOS ONE Editors concluded that the study did not comply with the journal’s Animal Research Policy. Therefore, the PLOS ONE Editors retract this article. The editors regret that these concerns were not identified prior to the article’s publication.

BP, SP, VY and BS did not respond or could not be reached. BBA did not respond to the retraction decision.

Aggarwal retired from MD Anderson in 2015, and even after several retractions, he made Thomson Reuters’ list of top-cited scientists in 2016. He is now tied for 23rd on our leaderboard of researchers with the most retractions.

We asked David Knutson, the senior communications manager for PLOS, about why its journal decided to retract the paper now, a decade after correcting the article. He told us: 

We cannot at this time speak to details of the 2012 case that led to the Figure 1C Correction, although we speculate that the tumor concerns discussed in the recent retraction notice were likely not flagged or evaluated at that time. Our internal processes for addressing post-publication concerns have evolved over the past decade, and since our Publication Ethics team formed in 2018, we have taken a more comprehensive approach to evaluating articles for which concerns are raised. Even so, additional issues may be identified after publication of a Correction or other post-publication notice. In such cases, unless the article has already been retracted, we follow up in accordance with COPE guidance and PLOS policies as for any other publication ethics case and take additional editorial action when warranted.

We opened a new investigation of doi: 10.1371/journal.pone.0026943 earlier in 2022, because concerns were raised about the animal tumor sizes reported in Figure 2. As is explained in the retraction notice, PLOS discussed the concerns with the authors, an expert in laboratory animal welfare, and the University of Texas MD Anderson Cancer Center IACUC. Based on the outcome of our assessment and in line with the IACUC’s recommendation, PLOS ONE retracted the article because we concluded that the study did not comply with the journal’s Animal Research Policy.

The raiser of those concerns was “an external party” who emailed the journal directly, Knutson added.

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