Detection of aberrant methylation in fecal DNA as a molecular screening tool for colorectal cancer and precancerous lesions

Table 1 Characteristics of patients

Characteristics	Colorectal cancern = 52	Benign controln = 35	Normal controln = 24
Sex
Male	31	20	13
Female	21	15	11
Age
Mean ± SD	63.5 ± 11.8	60.0 ± 10.3	59.6 ± 8.2
Range	25-81	31-79	35-68
Dukes stage
A + B	27	Na	Na
C + D	25	Na	Na
Nodal status
Positive	23	Na	Na
Negative	29	Na	Na
Tumor size
> 5 cm	19	Na	Na
≤ 5 cm	33	Na	Na
Tumor locus
Rectum	24	Na	Na
Distal colon	16	Na	Na
Proximal colon	12	Na	Na

Na: not applicable.

Table 2 Primers for MSP

Primer	Sequences (5’-3’)	Annealingtemperature	Productsize (bp)
SRFP2-MF	GGGTCGGAGTTTTTCGGAGTTGCGC	62°C	138
SRFP2-MR	CCGCTCTCTTCGCTAAATACGACTCG
SRFP2-UF	TTTTGGGTTGGAGTTTTTTGGAGTTGTGT	58°C	145
SRFP2-UR	AACCCACTCTCTTCACTAAATACAACTCA
HPP1-MF	TTTAGCGGACGATTTTTTCGTTTCG	57°C	122
HPP1-MR	AACGACGACGATAACAATAA
HPP1-UF	TTTAGTGGATGATTTTTTTGTTTTG	57°C	122
HPP1-UR	AACAACAACAATAACAATAA
MGMT-MF	TTTCGACGTTCGTAGGTTTTCGC	56°C	81
MGMT-MR	GCACTCTTCCGAAAACGAAACG
MGMT-UF	TTTGTGTTTTGATGTTTGTAGGTTTTTGT	59°C	93
MGMT-UR	AACTCCACACTCTTCCAAAAACAAAACA

U: unmethylated; M: methylated; F: forward; R: reverse.

Table 3 Methylation of SFRP2, HPP1 and MGMT in stool samples n (%)

Diagnosis	No	Gene locus			Total
		SFRP2	HPP1	MGMT
Cancer	52	49 (94.2)	37 (71.2)	25 (48.1)	50 (96.2)
Adenomas	21	11 (52.4)	12 (57.1)	6 (28.6)	15 (71.4)
Advanced adenomas	10	7 (70.0)	7 (70.0)	4 (40.0)	8 (80.0)
Hyperplastic polyp	8	3 (37.5)	2 (25.0)	1 (12.5)	3 (37.5)
Ulcerative colitis	6	1 (16.7)	1 (16.7)	0 (0)	1 (16.7)
Normal	24	1 (4.2)	0 (0)	0 (0)	1 (4.2)