Table 5.

Agreement study of methylation status at each of the 16 CpG islands within 10 synchronous cancer pairs.

					Concordance	κ coefficient	P value
All cases (N=10 pairs × 16 markers)					0.78	0.53	<0.0001
		Tumor 2
		+	−	Total
Tumor 1	+	45	27	72
	−	9	79	88
	Total	54	106	160
Proximal colon*/proximal colon* (N=3 pairs × 16 markers)					0.81	0.41	0.010
		Tumor 2
		+	−	Total
Tumor 1	+	34	6	40
	−	3	5	8
	Total	37	11	48
Distal colorectum**/distal colorectum** (N=2 pairs × 16 markers)					0.94	0.80	0.0001
		Tumor 2
		+	−	Total
Tumor 1	+	5	2	7
	−	0	25	25
	Total	5	27	32
Proximal colon*/distal colorectum** (N= 5 pairs × 16 markers)					0.69	0.15	0.18
		Tumor 2
		+	−	Total
Tumor 1	+	6	19	25
	−	6	49	55
	Total	12	68	80

^*Proximal colon refers to cecum to transverse colon.

^**Distal colorectum refers to splenic flexure to rectum.