Clinical significance of telomerase and its associate genes expression in the maintenance of telomere length in squamous cell carcinoma of the esophagus

Table 1 Clinical characteristics of 74 patients with esophageal cancer

	Numbers of patients
Age (mean), years	36-79 (59.5)
Sex
Male	71
Female	3
Differentiation
Well	0
Moderate	49
Poor	25
Tumor site
T1	3
T2	10
T3	50
T4	11
Lymph node
N0	24
N1	50
Metastasis
M0	60
M1	14
Stage
I	2
II	25
III	33
IV	14

Table 2 Expression of telomerase activity according to the clinicopathological characteristics of 74 esophageal cancer patients

	Telomerase (+)	Telomerase (-)	P value1
Gender			1.0
Female	3	0
Male	60	11
Differentiation			0.492
Well to moderate	20	5
Poor	43	6
Tumor Size			1.0
T1+T2	11	2
T3+T4	52	9
Lymph node			0.321
N0	19	5
N1	44	6
Metastasis			0.11
M0	49	11
M1	14	0
Stage			0.194
I+II	21	6
III+IV	42	5

¹Fisher's exact test (if expectation<5) or Yate's correction of contingency.

Table 3 Expression of telomerase associate genes of the tumor and normal tissues in 74 esophageal cancer patients

Expression	Positive	Negative	P-values1
TRF1			0.002
Tumor	61	13
Normal	43	31
TRF2			1.0
Tumor	68	6
Normal	67	7
c-Myc			0.16
Tumor	70	4
Normal	64	10
hTERT			0.0002
Tumor	48	26
Normal	24	50
hTERC			<0.0001
Tumor	59	14
Normal	30	44
TP1	N/A
Tumor	74	0
Normal	74	0
Tissue			0.288
Tumor	63	11
Normal	24	50	<0.0001

¹Pearson’s χ²-test.

Table 4 Expression of telomerase associate genes of the tumor tissues according to the telomerase activity in 74 esophageal cancer patients

	Telomerase (+)	Telomerase (-)	P-value1
hTERT			0.737
Positive	40	8
Negative	23	3
hTERC			0.684
Positive	51	8
Negative	12	3
c-Myc			0.103
Positive	61	9
Negative	2	2
TRF1			0.396
Positive	53	8
Negative	10	3
TRF2			0.0391
Positive	60	8
Negative	3	3
TP1			N/A
Positive	63	11
Negative	0	0

¹Fisher's exact test (if expectation<5) or Yate's correction of contingency.

Table 5 TRFL and t/n TRFLR of the tumor tissues according to the telomerase expression and TNM stages

Variables	TRFL	P- values	t/n TRFLR	P- values
Tissues		<0.00011
Normal	4.93±1.74 kb
Tumor	2.70±1.42 kb
Telomerase		0.7671		0.7422
Positive	2.72±1.44 kb		0.55±0.22
Negative	2.58±1.32 kb		0.59±0.41
Tumor stages		0.9362		0.8672
Stage I	3.04±0.42 kb		0.818±0.019
Stage II	2.65±1.44 kb		0.686±0.184
Stage III	2.83±1.44 kb		0.729±0.265
Stage IV	2.41±1.49 kb		0.649±0.185
Total	2.70±1.42 kb		0.73±0.24

P values:

¹Paired t-test,

²Independent t-test.

Table 6 Multivariate survival analysis for Cox proportional hazards model

Risk factors (# Patients)	Coefficients (SE)	Relative risk (95%CI)	P-values1
t/n TRFLR	0.78 (0.37)	(1.06-4.48)	0.035
≤85% (n = 57)		1
＞85% (n = 17)		2.18
T-status	1.17 (0.78)	(0.70-15.06)	0.134
T1+T2 (n = 13)		1
T3+T4 (n = 61)		3.24
N-status	1.06 (0.66)	(0.79-10.48)	0.108
N0 (n = 24)		1
N1+N2 (n = 50)		2.88
M-status	0.87 (0.43)	(1.03-5.49)	0.042
M0 (n = 60)		1
M1 (n = 14 )		2.38
Stage	-0.90 (0.78)	(0.09-1.89)	0.251
I+II (n = 27)		1
III+IV (n = 47)		0.41
Differentiation	0.33 (0.35)	(0.70-2.76)	0.352
W+M (n = 25)		1
P (n = 49)		1.39
Telomerase expression	-0.11 (0.46)	(0.36-2.22)	0.811
Negative (n = 11)		1
Positive (n = 63)		0.9

¹Wald statistic