Clinical and molecular features of young-onset colorectal cancer

Table 1 Clinicopathologic and molecular differences between young-onset and late-onset colorectal cancer

Clinical and molecular characteristics	Young-onset CRC( ≤50 yr)	Late-onset CRC(> 50 yr)
Proximal colon		X
Distal colon and rectum	X
Synchronous and metachronous CRC	X
Later stage at diagnosis (stage III/IV)	X
Mucinous/signet ring and poorly differentiated features	X
Typically MSS	X
MSI due to MLH1 gene promoter methylation		X
CIN		X
CIMP-low	X
CIMP-high		X
Microsatellite and chromosome stable CRC	X
Hypomethylation of LINE 1	X

CRC: Colorectal cancer; MSS: Microsatellite stable; MSI: Microsatellite instability; CIN: Chromosomal instability; CIMP: CpG island methylator phenotype; MACS: Microsatellite and chromosome stable CRC.