Methylation of Serum DNA Is an Independent Prognostic Marker in Colorectal Cancer

DOI: 10.1158/1078-0432.CCR-06-1264 Published December 2006

Article Figures & Data

Download figure
Open in new tab
Download powerpoint
Fig. 1.
Kaplan-Meier analysis of the probability of survival.

Table 1.

Characteristics of the gene evaluation and test sets

Characteristics	Gene evaluation set (n = 38), %	Test set (n = 104), %	P*
Gender			0.117
Male	68	56
Female	32	44
Size of tumor^†			0.631
T₁	5	8
T₂	5	12
T₃	69	68
T₄	21	12
Nodal status^†			0.912
N₀	40	52
N₁	60	48
Distant metastases^†			0.675
M₀	63	83
M₁	37	17
Localization^†^‡
Right^§	38	24	0.739
Left^∥	62	76
Colon	62	58	0.739
Rectum	38	42
Grading			0.504
G1	3	3
G2	44	52
G3^¶	53	45
UICC stage			0.196
I	10	14
II	21	33
III	32	36
IV	37	17

↵* P values for the comparison of numbers of patients were calculated by means of the χ² test.
↵† For one patient of the test set, tumor localization and information on TNM staging was not available.
↵‡ For one patient of the gene evaluation set, tumor localization was unknown.
↵§ Right colon includes cecum through transverse colon.
↵∥ G3 left colon includes descending colon through rectum.
↵¶ G3 includes all cases classified as G3 or as G2-G3.

Table 2.
Frequency of methylated genes in serum DNA of the gene evaluation set
Gene Healthy controls (n = 20) Local disease (n = 24) Metastasized disease (n = 14)
APC 20 21 43
HIC1 10 4 14
HLTF 0 17 50
hMLH1 0 4 43
HPP1 0 13 36
p16 60 25 64
RASSF1A 10 4 0
SFRP1 10 17 0
SFRP2 0 4 7
SFRP4 5 13 0
SFRP5 5 4 14
WT1 15 4 0
NOTE: Values in table expressed as % positive.
Table 3.
Distribution of PMR values in serum of 141 patients with colorectal cancer
PMR HLTF HPP1 hMLH1
I+II III IV I+II III IV I+II III IV
0 50 41 16 58 45 17 42 32 19
0-5 3 2 4 3 2 6 11 13 7
5-25 2 5 2 0 2 4 1 3 1
>25 6 1 9 0 0 4 7 1 4

Table 4.

Frequency of methylated genes according to clinicopathologic features

Characteristics	No. patients*	HLTF		HPP1		hMLH1
Characteristics	No. patients*	% Positive	P^†	% Positive	P^†	% Positive	P^†
Size of tumor			0.03		0.021		0.047
T₁ + T₂ + T₃	90	28		11		20
T₄	13	46		23		46
Nodal status			0.514		0.026		0.494
N₀	54	20		6		24
N₁	49	22		20		22
Distant metastases			0.009		<0.001		0.181
M₀	86	16		5		26
M₁	17	47		53		12
Localization			0.049		0.156		0.100
Right^‡	25	2		4		12
Left^§	78	20		14		27
Colon	60	15	0.054	7	0.061	22	0.408
Rectum	43	30	0.054	19	0.061	26	0.408
Grading			0.872		0.796		0.316
G1	3	33		0		0
G2	53	21		13		19
G3^∥	45	22		13		29
UICC stage			0.042		<0.001		0.648
I	15	20		7		27
II	34	15		3		24
III	37	16		5		27
IV	17	47		53		12

↵* For one patient, tumor localization and information on TNM staging was not available.
↵† P values were calculated by the χ² test.
↵‡ Right colon includes cecum through transverse colon.
↵§ Left colon includes descending colon through rectum.
↵∥ Relative risk was calculated for G3 versus G1 and G2. G3 includes all cases classified as G3 or G2-G3.

Table 5.

Results of univariate analysis

Variable	No. patients who died/total no.	Relative risk of death (95% CI)*	P*
Size of tumor			0.025
T₁ + T₂ + T₃	21/66
T₄	7/10	1.3 (1.1-1.6)
Nodal status			0.065
N₀	10/39
N₁	18/37	1.4 (1.0-3.8)
Distant metastases			0.034
M₀	19/61
M₁	9/15	2.5 (1.1-5.6)
Localization
Right^†	6/17
Left^‡	22/60	1.1 (0.4-2.7)	0.873
Colon	12/40
Rectum	16/37	1.3 (0.9-1.9)	0.198
Grading			0.363
G1	0/1
G2	13/38
G3^§	14/35	1.2 (0.6-2.6)
UICC stage			0.025
I	3/10
II	5/24	0.7 (0.2-2.9)
III	11/27	2.1 (0.7-6.0)
IV	9/15	1.9 (0.8-4.5)
HLTF methylation			0.008
Unmethylated	17/60
Methylated	11/17	3.0 (1.4-6.4)
HPP1 methylation			0.001
Unmethylated	20/68
Methylated	8/9	5.1 (2.2-11.6)
hMLH1 methylation			0.425
Unmethylated	20/59
Methylated	8/18	1.4 (0.6-3.1)
HPP1 ± HLTF			<0.001
Unmethylated	14/57
Methylated	14/20	4.2 (2.0-9.0)

↵* 95% CIs and P values were calculated by the Cox proportional hazards regression analysis.
↵† Right colon includes cecum through transverse colon.
↵‡ Left colon includes descending colon through rectum.
↵§ G3 includes all cases classified as G3 or as G2-G3. The relative risk was calculated for G1 and G2 versus G3.

Table 6.

Multivariate analysis