Early-onset gastric cancer: Learning lessons from the young

Table 2 Clinico-pathological and molecular-genetic differences between early-onset and conventional gastric cancers

Conventional gastric cancer	Early-onset gastric cancer	Ref.
Equally common in male and females	More common in females	[13,28,30,31]
Intestinal type cancer more common	Diffuse type cancer more common	[13,28]
Usually unifocal	Often multifocal	[32,33]
Often preceded by intestinal metaplasia	No intestinal metaplasia	[13,28]
Microsatellite Instability in 15%-20%	Lack of MSI	[24,29,41-43]
Commonly find loss of heterozygosity	Infrequent loss of heterozygosity	[24]
COX2 overexpression in 66%	COX2 overexpression in 10%	[46]
Loss of TFF1 expression in 73%	Loss of TFF1 expression in 39%	[46]
Loss of RUNX3 gene	No loss of RUNX3	[58-61]
Widespread gains throughout genome	Gains at chromosomes 17q, 19q and 20q	[40]
Distinct gene clusters on hierarchical analysis	Distinct gene clusters on hierarchical analysis	[39]
Infrequent LMW isoforms of cyclin E	Frequent LMW isoforms of cyclin E	[52]
CD44v6 expression	CD44v6 more commonly expressed	[57]
Usually no family history	10% with a family history	[13]