Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Feb 10, 2016; 7(1): 54-86
Published online Feb 10, 2016. doi: 10.5306/wjco.v7.i1.54
Historical review of the causes of cancer
Clarke Brian Blackadar
Clarke Brian Blackadar, Department of Food Science, Ontario Agricultural College, University of Guelph, Guelph, ON N1G 2W1, Canada
Author contributions: Blackadar CB solely contributed to this review.
Conflict-of-interest statement: I declare that I have no conflicts of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Clarke Brian Blackadar, Visting Researcher, Department of Food Science, Ontario Agricultural College, Universtity of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada.
Telephone: +1-519-7807420 Fax: +1-519-8246631
Received: August 20, 2015
Peer-review started: August 22, 2015
First decision: September 22, 2015
Revised: October 31, 2015
Accepted: November 24, 2015
Article in press: November 25, 2015
Published online: February 10, 2016
Core Tip

Core tip: The International Agency for Research on Cancer has worked for around 45 years evaluating the scientific literature, concerning the potential of around 1000 different agents to cause cancer. Those agents which were determined to definitively cause cancer in humans are reviewed from a historical perspective. It is reviewed how there were many complexities in identifying infectious agents as causes of cancer. The author incidentally discovered while writing this review that natural factors are an additional and relatively underappreciated cause of cancer.