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Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Apr 10, 2016; 7(2): 200-213
Published online Apr 10, 2016. doi: 10.5306/wjco.v7.i2.200
Role of the microbiome in non-gastrointestinal cancers
Meirav Pevsner-Fischer, Timur Tuganbaev, Mariska Meijer, Sheng-Hong Zhang, Zhi-Rong Zeng, Min-Hu Chen, Eran Elinav
Meirav Pevsner-Fischer, Timur Tuganbaev, Eran Elinav, Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
Mariska Meijer, Leiden University Medical Centre, Leiden University, 2300 RC Leiden, the Netherlands
Sheng-Hong Zhang, Zhi-Rong Zeng, Min-Hu Chen, Division of Gastroenterology, the First Affiliated Hospital, Sun Yat-sen University, 51008 Guangzhou, Guangdong Province, China
Author contributions: All authors equally contributed to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and final approval of the final version.
Conflict-of-interest statement: 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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Eran Elinav, MD, PhD, Department of Immunology, Weizmann Institute of Science, 100 Herzl Street, Rehovot 7610001, Israel. eran.elinav@weizmann.ac.il
Telephone: +972-8-9344014
Received: July 15, 2015
Peer-review started: July 17, 2015
First decision: November 3, 2015
Revised: January 24, 2016
Accepted: February 23, 2016
Article in press: February 24, 2016
Published online: April 10, 2016
Abstract

“The forgotten organ”, the human microbiome, comprises a community of microorganisms that colonizes various sites of the human body. Through coevolution of bacteria, archaea and fungi with the human host over thousands of years, a complex host-microbiome relationship emerged in which many functions, including metabolism and immune responses, became codependent. This coupling becomes evident when disruption in the microbiome composition, termed dysbiosis, is mirrored by the development of pathologies in the host. Among the most serious consequences of dysbiosis, is the development of cancer. As many as 20% of total cancers worldwide are caused by a microbial agent. To date, a vast majority of microbiome-cancer studies focus solely on the microbiome of the large intestine and the development of gastrointestinal cancers. Here, we will review the available evidence implicating microbiome involvement in the development and progression of non-gastrointestinal cancers, while distinguishing between viral and bacterial drivers of cancer, as well as “local” and “systemic”, “cancer-stimulating” and “cancer-suppressing” effects of the microbiome. Developing a system-wide approach to cancer-microbiome studies will be crucial in understanding how microbiome influences carcinogenesis, and may enable to employ microbiome-targeting approaches as part of cancer treatment.

Keywords: Microbiome, Non-gastrointestinal cancers, Carcinogenesis, Dysbiosis, Microbial agent

Core tip: “The forgotten organ”, the human microbiome, comprises a community of microorganisms that colonizes various sites of the human body. A complex host-microbiome relationship has emerged in which many functions became codependent. This coupling becomes evident when disruption in the microbiome composition, termed dysbiosis, is mirrored by the development of pathologies in the host. Among the most serious consequences of dysbiosis, is the development of cancer. As many as 20% of total cancers worldwide are caused by a microbial agent. Here, we will review the available evidences implicating microbiome involvement in the development and progression of non-gastrointestinal cancers. Developing a system-wide approach to cancer-microbiome studies will be crucial in understanding how microbiome influences carcinogenesis, and may enable to employ microbiome-targeting approaches as part of cancer treatment.