Telomerase activity in colorectal cancer, prognostic factor and implications in the microsatellite instability pathway

Table 1 Relationship of telomerase activity and MSI with clinicopathological variables of the 97 patients with colorectal carcinoma n (%)

Variable					P	Telomerase		P
		MSS	MSI-L	MSI-H		Positive	Negative
Sex	Men: 51 (52.6)	40 (78.4)	7 (13.7)	4 (7.8)	0.20	46 (90.2)	5 (9.8)	0.44
	Female: 46 (47.4)	41 (89.1)	3 (6.5)	2 (4.3)		44 (95.7)	2 (4.3)
Age	≥ 71 yr: 50 (51.5)	39 (78.0)	5 (10.0)	6 (12.6)	0.03	47 (94.0)	3 (6.0)	0.70
	< 71 yr: 47 (48.5)	42 (89.4)	5 (10.6)	0 (0)		43 (91.5)	4 (8.5)
Dukes stage	A+B: 47 (48.5)	40 (85.1)	4 (8.5)	3 (6.4)	0.90	42 (89.4)	5 (10.6)	0.13
	C: 26 (26.8)	22 (84.6)	1 (3.8)	3 (11.5)		24 (92.3)	2 (7.7)
	D: 24 (24.7)	19 (79.2)	5 (20.8)	0 (0)		24 (100)	0 (0)
Site	Colon: 70 (72.2)	56 (80.0)	8 (11.4)	6 (8.6)	0.08	67 (95.7)	3 (4.3)	0.09
	Rectum: 27 (27.8)	25 (92.6)	2 (7.4)	0 (0)		23 (85.2)	4 (14.8)
Colon site	Proximal: 37 (52.8)	26 (70.3)	5 (13.5)	6 (16.2)	0.01	34 (91.9)	3 (8.1)	0.04
	Distal: 33 (47.2)	30 (92.6)	3 (9.1)	0 (0)		33 (100)	0 (0)
Grade	I: 56 (65.9)	47 (83.9)	6 (10.7)	3 (5.4)	0.32	27 (93.1)	2 (6.9)	1.00
	II + III: 29 (34.1)	22 (75.9)	4 (13.8)	3 (10.3)		52 (92.9)	4 (7.1)
Histological	Adenocarcinoma: 87	72 (82.8)	9 (10.3)	6 (6.9)	0.44	80 (92.0)	7 (8.0)	1.00
	(89.7)	9 (90.0)	1 (10.0)	0 (0)		10 (100)	0 (0)
type	Mucoid: 10 (10.3)
Chemo therapy	Yes: 52 (53.6)	44 (84.6)	6 (11.5)	2 (3.8)	0.50	49 (94.2)	3 (5.8)	0.70
	No: 45 (46.4)	37 (82.2)	4 (8.9)	4 (8.9)		41 (91.1)	4 (8.9)

MSS: absence of microsatellite instability; MSI-L: low instability; MSI-H: high instability. Statistically significant: P < 0.05.

Table 2 Relationship between telomerase activity and MSI n (%)

	Telomerase positive	Telomerase negative	P
MSS	76 (93.8)	5 (6.2)	0.89
MSI-L	9 (90.0)	1 (10.0)
MSI-H	5 (83.3)	1 (16.7)

Table 3 Univariate analysis OS

Variable	OS (40 mo, %)		HR1	95% CI	P
Sex	Men	63	1.7	0.75-3.84	0.19
	Female	77
Age	≥ 71 yr	68	1.19	0.54-2.62	0.65
	< 71 yr	71
Dukes stage	A+B	95			< 0.0001
	C	83	3.4	0.63-18.90
	D	5	48.08	11.03-209.5
Site	Colon	70			0.73
	Rectum	67	1.16	0.50-2.70
Colon site	Proximal	67	1.23	0.47-3.24	0.66
	Distal	74
Grade	I	78			0.27
	II	59	2.04	0.84-4.94
	III	66	1.49	1.19-11.58
Histological	Adenocarcinoma 72				0.29
type	Mucoid	46	1.88	0.66-5.55
Chemo	Yes	63	2.06	0.82-5.18	0.10
therapy	No	82
MSI	MSS	70			0.94
	MSI-L	62	1.11	0.33-3.74
	MSI-H	75	0.77	0.10-5.77
Telomerase	Positive	67	22.93	0.04-12.084	0.04
	Negative	100

MSS: absence of microsatellite instability; MSI-L: low instability; MSI-H: high instability; OS: overall survival; HR: hazard ratio; 95% CI: 95% confidence interval.

¹HR are adjusted for the variables of the table. Median follow-up time: 40 mo. Cox analysis. Statistically significant: P < 0.05.

Table 4 OS analysis for telomerase activity stratified by MSI

		OS (40 mo, %)	P
	MSS	68	0.99
Telomerase positive	MSI-L	60
	MSI-H	66
	MSS	100	-
Telomerase negative	MSI-L	100
	MSI-H	100

MSS: absence of microsatellite instability; MSI-L: low instability; MSI-H: high instability; OS: overall survival. Statistically significant: P < 0.05.