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International Cancer Microbiome Consortium consensus statement on the role of the human microbiome in carcinogenesis
  1. Alasdair J Scott1,
  2. James L Alexander1,
  3. Claire A Merrifield1,
  4. David Cunningham2,
  5. Christian Jobin3,
  6. Robert Brown1,
  7. John Alverdy4,
  8. Stephen J O’Keefe5,
  9. H Rex Gaskins6,
  10. Julian Teare1,
  11. Jun Yu7,
  12. David J Hughes8,
  13. Hans Verstraelen9,
  14. Jeremy Burton10,
  15. Paul W O’Toole11,
  16. Daniel W Rosenberg12,
  17. Julian R Marchesi1,
  18. James M Kinross1
  1. 1 Department of Surgery and Cancer, Imperial College London, London, UK
  2. 2 Gastrointestinal Unit, Royal Marsden Hospital, London, UK
  3. 3 Division of Gastroenterology, Hepatology andNutrition, University of Florida College of Medicine, Gainesville, Florida, USA
  4. 4 Department of Surgery, University of Chicago, Chicago, Illinois, USA
  5. 5 Division of Gastroenterology, Hepatology andNutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
  6. 6 Carl R. Woese Institute for Genomic Biology,Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
  7. 7 Department of Medicine and Therapeutics, StateKey Laboratory of Digestive Diseases, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China
  8. 8 Cancer Biology and Therapeutics Group (CBT), Conway Institute, School of Biomolecular andBiomedical Science (SBBS), University College Dublin, Dublin, Ireland
  9. 9 Department of Obstetrics and Gynaecology,Vulvovaginal Disease Clinic, Ghent University Hospital, Belgium
  10. 10 Canadian Centre for Human Microbiome and Probiotics Research, Lawson Health Research Institute, London, Ontario, Canada
  11. 11 School of Microbiology & APC MicrobiomeIreland, University College Cork, Cork, Ireland
  12. 12 Center for Molecular Oncology, University of Connecticut School of Medicine, Farmington, Connecticut, USA
  1. Correspondence to Professor Julian R Marchesi, Department of Surgery and Cancer, Imperial College London, London W2 1NY, UK; j.marchesi{at}


Objective In this consensus statement, an international panel of experts deliver their opinions on key questions regarding the contribution of the human microbiome to carcinogenesis.

Design International experts in oncology and/or microbiome research were approached by personal communication to form a panel. A structured, iterative, methodology based around a 1-day roundtable discussion was employed to derive expert consensus on key questions in microbiome-oncology research.

Results Some 18 experts convened for the roundtable discussion and five key questions were identified regarding: (1) the relevance of dysbiosis/an altered gut microbiome to carcinogenesis; (2) potential mechanisms of microbiota-induced carcinogenesis; (3) conceptual frameworks describing how the human microbiome may drive carcinogenesis; (4) causation versus association; and (5) future directions for research in the field.

The panel considered that, despite mechanistic and supporting evidence from animal and human studies, there is currently no direct evidence that the human commensal microbiome is a key determinant in the aetiopathogenesis of cancer. The panel cited the lack of large longitudinal, cohort studies as a principal deciding factor and agreed that this should be a future research priority. However, while acknowledging gaps in the evidence, expert opinion was that the microbiome, alongside environmental factors and an epigenetically/genetically vulnerable host, represents one apex of a tripartite, multidirectional interactome that drives carcinogenesis.

Conclusion Data from longitudinal cohort studies are needed to confirm the role of the human microbiome as a key driver in the aetiopathogenesis of cancer.

  • microbiome, cancer, colorectal, oncology, consensus

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  • Contributors AJS, JA, CAM, JMK and JM planned the consensus statement and organised the ICMC roundtable discussion, proposing broad topics for discussion. AJS, JA, CAM, JMK, JM, DC, CJ, RB, JA, SJO, HRG, JT, JY, DJH, HV, JB and DWR contributed to active discussion during the roundtable event. AJS, JA, CAM, JMK and JM drafted the manuscript. DC, CJ, RB, JA, SJO, HRG, JT, JY, DJH, HV, JB, PWO and DWR revised the manuscipt. JMK and JM act as guarantors of the content of the manuscript.

  • Funding The roundtable discussion was funded by Cancer Research UK (Award C42378/A25637). The Division of Integrative Systems Medicine and Digestive Disease at Imperial College London receives financial support from the National Institute of Health Research (NIHR) Imperial Biomedical Research Centre (BRC) based at Imperial College Healthcare NHS Trust and Imperial College London. This article is independent research funded by the NIHR BRC, and the views expressed in this publication are those of the authors and not necessarily those of the NHS, NIHR, or the Department of Health.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Correction notice This article has been corrected since it published Online First. The ninth author’s name has been corrected.

  • Patient consent for publication Not required.

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