Review
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jan 15, 2016; 8(1): 83-98
Published online Jan 15, 2016. doi: 10.4251/wjgo.v8.i1.83
Molecular approach to genetic and epigenetic pathogenesis of early-onset colorectal cancer
Gulcin Tezcan, Berrin Tunca, Secil Ak, Gulsah Cecener, Unal Egeli
Gulcin Tezcan, Berrin Tunca, Secil Ak, Gulsah Cecener, Unal Egeli, Department of Medical Biology, Faculty of Medicine, Uludag University, 16059 Bursa, Turkey
Author contributions: All authors contributed equally to performing literature search and analysing results; Tezcan G and Tunca B wrote the manuscript.
Conflict-of-interest statement: All authors declare 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: Berrin Tunca, PhD, Department of Medical Biology, Faculty of Medicine, Uludag University, Görükle Kampüsü, 16059 Bursa, Turkey. btunca@uludag.edu.tr
Telephone: +90-224-2954161 Fax: +90-224-4428863
Received: June 24, 2015
Peer-review started: June 28, 2015
First decision: September 17, 2015
Revised: October 1, 2015
Accepted: November 10, 2015
Article in press: November 11, 2015
Published online: January 15, 2016
Abstract

Colorectal cancer (CRC) is the third most frequent cancer type and the incidence of this disease is increasing gradually per year in individuals younger than 50 years old. The current knowledge is that early-onset CRC (EOCRC) cases are heterogeneous population that includes both hereditary and sporadic forms of the CRC. Although EOCRC cases have some distinguishing clinical and pathological features than elder age CRC, the molecular mechanism underlying the EOCRC is poorly clarified. Given the significance of CRC in the world of medicine, the present review will focus on the recent knowledge in the molecular basis of genetic and epigenetic mechanism of the hereditary forms of EOCRC, which includes Lynch syndrome, Familial CRC type X, Familial adenomatous polyposis, MutYH-associated polyposis, Juvenile polyposis syndrome, Peutz-Jeghers Syndrome and sporadic forms of EOCRC. Recent findings about molecular genetics and epigenetic basis of EOCRC gave rise to new alternative therapy protocols. Although exact diagnosis of these cases still remains complicated, the present review paves way for better predictions and contributes to more accurate diagnostic and therapeutic strategies into clinical approach.

Keywords: Early-onset, Colorectal cancer, Epigenetic mechanism, Genetic mechanism, Clinical outcome

Core tip: Early-onset colorectal cancer (EOCRC) cases are heterogeneous population that include both hereditary and sporadic forms of the colorectal cancer (CRC). EOCRC cases have some distinguishing clinical and pathological features than elder age CRC. Recent findings about molecular genetics and epigenetic basis of EOCRC gave rise to new alternative therapy protocols. We herein discuss the latest findings about genetic and epigenetic features of EOCRC.