Correlation of N-myc downstream-regulated gene 1 expression with clinical outcomes of colorectal cancer patients of different race/ethnicity

Table 1 Correlation of NDRG1 expression with clinicopathologic variables in Japanese cases

	Total cases (%)	Positive	Negative	P value
	n = 80	n = 55	n = 25
Age (yr)				0.622
> 66	48 (60.0)	34	14
< 66	32 (40.0)	21	11
Gender				0.649
Male	45 (56.3)	30	15
Female	35 (43.7)	25	10
Tumor location				0.164
Right-hemicolon	28 (35.0)	22	6
Left-hemicolon	52 (65.0)	33	19
Histopathological Type				0.067
Well	39 (48.8)	22	17	0.017
Moderate	38 (47.6)	31	7
Poor	1 (1.2)	1	0
Mucinous	1 (1.2)	1	0
Sig	1 (1.2)	0	1
Dukes’ stage				0.036
A	22 (27.5)	11	11
B	21 (26.3)	14	7
C	27 (33.7)	20	7
D	10 (12.5)	10	0
Liver metastasis				0.062
Negative	73 (91.3)	48	25
Positive	7 (8.7)	7	0
Lymph node metastasis				0.14
Negative	48 (60.0)	30	18
Positive	32 (40.0)	25	7
Lymphatic invasion				0.021
Negative	19 (23.8)	9	10
Positive	61 (76.2)	46	15
Venous invasion				0.0077
Negative	15 (18.8)	6	9
Positive	65 (81.2)	49	16
Depth of invasion				0.01
m	5 (6.3)	1	4
sm	8 (10.0)	4	4
mp	14 (17.5)	10	4
ss, a1	29 (36.3)	23	6
se, a2	23 (28.7)	16	7
si, ai	1 (1.2)	1	0

P < 0.05 is considered significant.

Table 2 Correlation of NDRG1 expression with clinicopathologic variables in U.S. (Caucasian and African American) cases

	All U.S. cases (n = 77)				Caucasian (n = 43)				African American (n = 34)
	NDRG1				NDRG1				NDRG1
	Total (%)	+	-	P value	Total (%)	+	-	P value	Total (%)	+	-	P value
Age (yr)				0.079				0.092				0.464
> 66	45 (58.4)	19	26		26 (60.5)	10	16
< 66	32 (41.6)	20	12		17 (39.5)	11	6		19 (55.9)	9	10
Gender				0.074				0.255	15 (44.1)	9	6	0.153
Male	58 (75.3)	26	32		32 (74.4)	14	18
Female	19 (24.7)	13	6		11 (25.6)	7	4		26 (76.5)	12	14
Histopathological type				0.31				0.21	8 (23.5)	6	2	0.18
Well	47 (61.0)	20	27	0.15a	28 (65.1)	11	17	0.049a				0.88a
Moderate	23 (29.9)	14	9		14 (32.6)	10	4		19 (55.9)	9	10
Poor	2 (2.6)	1	1		0 (0)	0	0		9 (26.5)	4	5
Mucinous	5 (6.5)	4	1		1 (2.3)	0	1		2 (5.9)	1	1
Dukes’ stage				0.056				0.0063	4 (11.8)	4	0	0.88
A	7 (9.1)	1	6		4 (9.3)	0	4
B	28 (36.4)	14	14		16 (37.2)	8	8		3 (8.8)	1	2
C	23 (29.9)	16	7		14 (32.6)	11	3		12 (35.3)	6	6
D	19 (24.6)	8	11		9 (20.9)	2	7		9 (26.5)	5	4
Liver metastasis				0.39				0.072	10 (29.4)	6	4	0.59
Negative	58 (75.3)	31	27		34 (79.1)	19	15
Positive	19 (24.7)	8	11		9 (20.9)	2	7		24 (70.6)	12	12
Lymph node metastasis				0.212				0.28	10 (29.4)	6	4	0.52
Negative	35 (45.5)	15	20		20 (46.5)	8	12		15 (44.1)	7	8
Positive	42 (54.5)	24	18		23 (53.5)	13	10		19 (55.9)	11	8

^aP< 0.05vsmoderate.

Table 3 Frequency of expression of p53 and HIF-1α in Japanese and U.S. patients n (%)

	p53		HIF-1α
	Positive	Negative	Positive	Negative
Japanese (n = 80)	43 (54.0)	37 (46.0)	42 (52.5)	38 (47.5)
All U.S. cases (n = 77)	48 (62.3)	29 (37.7)	18 (23.4)	59 (76.6)
Caucasian (n = 43)	28 (65.1)	15 (34.9)	13 (30.2)	30 (69.8)
African American (n = 34)	20 (58.8)	14 (41.2)	5 (14.7)	29 (85.3)

Table 4 Correlation of expression of NDRG1 with p53 and HIF-1α

		NDRG1		P value
		Positive	Negative
Japanese (n = 80)
p53	+	31	12	0.49
	-	24	13
HIF-1α	+	25	17	0.061
	-	30	8
All U.S. cases (n = 77)
p53	+	28	20	0.083
	-	11	18
HIF-1α	+	13	5	0.036
	-	26	33
Caucasian (n = 43)
p53	+	16	12	0.14
	-	5	10
HIF-1α	+	10	3	0.015
	-	11	19
African American (n = 34)
p53	+	12	8	0.32
	-	6	8
HIF-1α	+	3	2	0.73
	-	15	14

P < 0.05 is considered significant.