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

Table 1 GST immunohistochemical expression according to a semiquantitative score in various types of mucosal lesions of the esophagus

Histology	Score (mean ± SD)
Normal epithelium (Control group)a (n = 7)	2.85 ± 0.24
Reflux esophagitis (n = 7)	1.14 ± 0.24
Barrett’s metaplasia (n = 14)	1.60 ± 0.34
Barrett’s metaplasia and reflux esophagitis (n = 8)	1.12 ± 0.35
Barrett’s metaplasia and dysplasiab (n = 7)	0.58 ± 0.37
Adenocarcinomabc (n = 8)	0.18 ± 0.25

^aP < 0.00001 vs the other groups;

^bP < 0.005 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.