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Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Mar 10, 2016; 8(5): 252-258
Published online Mar 10, 2016. doi: 10.4253/wjge.v8.i5.252
New era of colorectal cancer screening
Maysaa El Zoghbi, Linda C Cummings
Maysaa El Zoghbi, Linda C Cummings, Division of Gastroenterology and Liver Disease, University Hospitals Case Medical Center, Cleveland, OH 44106-5066, United States
Author contributions: El Zoghbi M and Cummings LC contributed equally to this paper.
Supported by An American College of Gastroenterology Junior Faculty Development Award to Linda C Cummings.
Conflict-of-interest statement: None.
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: Maysaa El Zoghbi, MD, Gastroenterology Fellow, Division of Gastroenterology and Liver Disease, University Hospitals Case Medical Center, 11000 Euclid Avenue, Cleveland, OH 44106-5066, United States.
Telephone: +1-216-8445386 Fax: +1-216-9830347
Received: April 30, 2015
Peer-review started: May 7, 2015
First decision: July 17, 2015
Revised: October 24, 2015
Accepted: December 29, 2015
Article in press: January 1, 2016
Published online: March 10, 2016

Colorectal cancer (CRC) is the 2nd most common cancer in women and 3rd most common cancer in men worldwide. Most CRCs develop from adenomatous polyps arising from glandular epithelium. Tumor growth is initiated by mutation of the tumor suppressor gene APC and involves other genetic mutations in a stepwise process over years. Both hereditary and environmental factors contribute to the development of CRC. Screening has been proven to reduce the incidence of CRC. Screening has also contributed to the decrease in CRC mortality in the United States. However, CRC incidence and/or mortality remain on the rise in some parts of the world (Eastern Europe, Asia, and South America), likely due to factors including westernized diet, lifestyle, and lack of healthcare infrastructure. Multiple screening options are available, ranging from direct radiologic or endoscopic visualization tests that primarily detect premalignant or malignant lesions such as flexible sigmoidoscopy, optical colonoscopy, colon capsule endoscopy, computed tomographic colonography, and double contrast barium enema - to stool based tests which primarily detect cancers, including fecal DNA, fecal immunochemical test, and fecal occult blood test. The availability of some of these tests is limited to areas with high economic resources. This article will discuss CRC epidemiology, pathogenesis, risk factors, and screening modalities with a particular focus on new technologies.

Keywords: Colorectal neoplasm, Prevention and control, Guidelines, Epidemiology, Colonoscopy, Capsule endoscopy, Computed tomographic colonography, Occult blood

Core tip: Multiple societies have issued screening guidelines for colorectal cancer (CRC). However, global CRC screening implementation can be challenging due to wide variability in healthcare infrastructure and resources in different countries. The practical implementation of CRC screening in a given area depends mainly upon availability of endoscopic resources. In areas with the greatest healthcare resources, colonoscopy remains the gold standard, although technological advances have provided alternative screening methods including computed tomographic colonography, fecal DNA testing, and colon capsule endoscopy. In areas with fewer healthcare resources, guaiac-based fecal occult blood testing is the predominant screening modality.