Value of endoscopic methylene blue and Lugol's iodine double staining and detection of GST-Π and telomerase in the early diagnosis of esophageal carcinoma

Table 1 Endoscopic MB and Lugol's iodine double staining (n, %)

Histology	n	Areas stained blue (%)	Areas between both the colors (%)	Areas stained brown (%)
Normal epithelium	53	49 (92.5)	4 (7.5)	0
Hyperplasia	21	13 (61.9)	6 (28.6)	2 (9.5)
Dysplasia	79	10 (12.6)	45 (57.0)	24 (30.4)
Low-grade	17	7 (41.2)	7 (41.2)	3 (17.6)
Moderate-grade	21	3 (14.3)	13 (61.9)	5 (29.4)
High-grade	41	0	25 (61.0)	16 (39.0)
Carcinoma	55	0	9 (16.4)	46 (83.6)
Carcinoma in situ	1	0	1 (100)	0
Squamous cell carcinoma	51	0	8 (15.7)	43 (84.3)
Adenocarcinoma	3	0	0	3 (100)
Total	208	72	64	72

χ² = 170.58, P<0.005.

Table 2 GST-Π protein expression in esophageal carcinogenesis (n, %)

Histology	n	GST-Π expression				Positiverate (%)
		-	+	++	++
Normal epithelium	53	50	3	0	0	5.7
Hyperplasia	21	19	2	0	0	9.51
Dysplasia	79	30	34	12	3	62.0b
Carcinoma	55	9	30	13	3	83.6b

¹P>0.9,

^bP<0.001 vs normal epithelium.

Table 3 GST-Π protein expression in various histology mucosa of esophagus (n, %)

Histology	n	GST-Π expression				Positiverate (%)
		-	+	++	++
Low-grade dysplasia	17	11	5	1	0	35.3
Moderate-grade dysplasia	21	9	8	3	1	57.1
High-grade dysplasia	41	10	21	8	2	75.6

P<0.025.

Table 4 Telomerase activity expression in esophageal carcinogenesis (n, %)

Histology	n	Telomerase activity expression		Positive numberof telomerase (%)
		+	-
Normal epithelium	53	25	1	2 (3.8)
Hyperplasia	21	1	20	1 (4.8)1
Dysplasia	79	41	28	41 (51.9)a
Carcinoma	55	49	6	49 (89.1)c

¹P = 0.998, hyperplasia vs normal epithelium;

^aP<0.005, χ² = 33.45, dysplasia vs normal epithelium;

^cP<0.005, χ² = 78.83, carcinoma vs normal epithelium.

Table 5 Telomerase activity expression in various histological mucosa of esophagus (n, %)

Histology	n	Telomerase activity expression		Positive numberof telomerase (%)
		+	-
Low-grade dysplasia	17	2	15	2 (11.8)
Moderate-grade dysplasia	21	7	14	7 (33.3)
High-grade dysplasia	41	32	9	32 (78.0)

Comparing among dysplasias χ² = 25.10, P<0.005; there was significant difference between high- and low- or moderate-grade dysplasia (χ² = 21.77, P<0.005; χ² = 11.90, P<0.005, respectively), but no obvious difference between low- and moderate-grade dysplasia (χ² = 1.37, P>0.1).

Table 6 Expressions of GST-Π and telomerase activity in esophageal carcinoma and premalignant lesions

	Normal epithelium		Hyperplasia		Dysplasia		Carcinoma
	GST- ϕ (+)	GST- ϕ (-)	GST- ϕ (+)	GST-Π (-)	GST-Π (+)	GST- ϕ (-)	GST-Π (+)	GST-Π (-)
TA (+)	0	2	0	1	36	5	43	6
TA (-)	3	48	2	18	13	25	3	3

TA: telomerase activity. Expression of GST-Π correlated to that of telomerase activity in dysplasia and carcinoma (φ = 0.4831,P<0.00; φ = 0.3031, P<0.025 respectively); but there was no correlation between the expression of GST-Π and telomerase activity in normal epithelium and hyperplasia (P>0.05).