Table 1.

Correlation of HIF-1α, CXCR4, and VEGF expression with clinicopathologic features in colon cancer. Sections were subjected to routine deparaffinization and rehydration. Antigen retrieval was achieved by microwaving in citrate buffer for 10 min. The endogenous peroxidase activity was inhibited by incubation with 3% hydrogen peroxide. The specimens were reacted overnight with anti-HIF-1α antibodies, anti-CXCR4 antibodies, and anti-VEGF antibodies, then were incubated with rat anti-mouse-IgG2b-horseradish peroxidase. The sections were then counterstained with hematoxylin and mounted (see Section 2). Staining intensity and percentage of positive tumor cells were assessed. Multiplication of the intensity and the percentage scores gave rise to the final staining score: 0 (negative), + (1–4), ++ (5–8), and +++ (9–12). For statistical analysis, tumors having staining scores of 0 or + were designated the low expression group, and tumors with scores of ++ or +++ the high expression group. The correlation between clinicopathologic parameters and HIF-1α, CXCR4, and VEGF expression were analyzed by Chi-squared test or Fisher's exact test. Abbreviations: HIF-1α: Hypoxia-inducible factor-1; CXCR4: CXC chemokine receptor 4; VEGF: vascular endothelial growth factor; HPP: hyperplastic polyps; TNM: tumor-node-metastasis.

Clinicopathologic parameters	Case No.	HIF-1α expression		P value	CXCR4 expression		P value	VEGF expression		P value
		Low	High		Low	High		Low	High
Total cases	68	38	30		27	41		24	44
Age
≤60	19	12	10	P = .878	8	11	P = .801	9	10	P = .195
>60	49	26	20		19	30		15	34
Tissue type
Normal colonic tissue	10	10	0	P = .002a	10	0	P < .001a	10	0	P < .001a
HPP	8	8	0	P = .006b	8	0	P < .001b	8	0	P < .001b
Colon cancer	68	38	30	P = .019c	27	41	P = .001c	24	44	P = .001c
Sex
Male	41	24	17	P = .587	15	26	P = .639	14	27	P = .807
Female	27	14	13		11	15		10	17
Tumor size
≤5 cm	27	16	11	P = .649	13	14	P = .297	17	10	P = .340
>5 cm	41	32	19		25	16		21	20
TNM stage
I	6	5	1		5	1		4	2
II	30	23	7	P = .001	16	14	P = .003	15	15	P = .008
III	25	9	16		6	19		5	20
IV	7	1	6		0	7		0	7
Lymph node metastasis
Negative	36	28	8	P < .001	21	16	P = .001	19	17	P = .001
Positive	32	10	22		6	26		5	27
Distant metastasis
Negative	61	37	24	P = .019	27	34	P = .037	24	37	P = .046
Positive	7	1	6		0	7		0	7

^aDenotes significant difference among the three tissue types.

^bDenotes significant difference between colon cancer and normal colonic tissue.

^cDenotes significant difference between colon cancer and HPP.