Alterations of glutathione S-transferase and matrix metalloproteinase-9 expressions are early events in esophageal carcinogenesis

Table 2 MMP-9 immunohistochemical expression according to a semiquantitative score in various types of mucosal lesions of the esophagus

Histology	Score (mean ± SD)
Normal epithelium (Control goup)b (n = 7)	0.28 ± 0.39
Reflux esophagitis (n = 7)	1.71 ± 0.39
Barrett’s metaplasia (n = 14)	1.46 ± 0.41
Barrett’s metaplasia and reflux esophagitis (n = 8)	1.75 ± 0.26
Barrett’s metaplasia and dysplasiaa (n = 7)	2.16 ± 0.25
Adenocarcinomaac (n = 8)	2.62 ± 0.35

^bP < 0.00001 vs the other groups;

^aP < 0.05 vs the other groups (normal epithelium, reflux esophagitis, barrett's metaplasia, barrett's metaplasia and Reflux esophagitis);

^cP < 0.05 vs barrett's metaplasia and dysplasia.