Genomic and molecular alterations associated with early-onset and adolescent and young adult colorectal cancer

Abstract

While the incidence of colorectal cancer (CRC) in the US has declined at a pace of 3% annually between 2003 and 2012, there has been an increase in the incidence of early-onset colorectal cancer (EOCRC). The reasons for this increase are unclear. Diet, the environment, the microbiome and alcohol consumption have all been proposed as contributing factors. There is the possibility that EOCRC has a unique biology. Overlapping with the EOCRC age range is CRC in adolescent and young adults (AYA) that share many molecular characteristics with EOCRC. The purpose of this review is to cover current progress in our understanding of the biology of CRC in the context of adolescent and young adult CRC and EOCRC and discuss future directions.