Correlation of N-myc downstream-regulated gene 1 overexpression with progressive growth of colorectal neoplasm

Table 1 Comparison between positive rate and positive unit (PU) of NDRG1 protein in all groups

Group	Cases	Positive number and percentage					Positive unit mean ± SD
		-	+	++	+++	%
Normal colorectal mucosa	38	17	21	0	0	55.26	45.34 ± 5.66
Colorectal adenomas	31	6	18	6	1	80.65	48.35 ± 4.79
Non-metastatic CRCs	45	2	24	19	0	95.56	51.62 ± 4.63
Metastatic CRCs	38	0	14	18	6	100.00	54.38±4.39
Regional lymph node metastatic sites	38	2	9	24	3	94.74	54.73 ± 4.56

Table 2 Comparison of positive rates of NDRG1 protein in all groups (P value)

Group	Normal colorectal mucosa	Colorectal adenomas	Non-metastatic CRCs	Metastatic CRCs	Regional lymph node metastatic sites
Normal colorectal mucosa	——	bP < 0.01	bP < 0.01	bP < 0.01	bP < 0.01
Colorectal adenomas	bP < 0.01	——	cP < 0.05	dP < 0.01	dP < 0.01
Non-metastatic CRCs	bP < 0.01	cP < 0.05	——	eP < 0.05	fP < 0.01
Metastatic CRCs	bP < 0.01	dP < 0.01	eP < 0.05	——
Regional lymph node metastatic sites	bP < 0.01	dP < 0.01	fP < 0.01		——

Table 3 Comparison of positive units (PU) of NDRG1 protein in all groups (P value)

Group	Normal colorectal mucosa	Colorectal adenomas	Non-metastatic CRCs	Metastatic CRCs	Regional lymph node metastatic sites
Normal colorectal mucosa	——	aP < 0.05	bP < 0.01	bP < 0.01	bP < 0.01
Colorectal adenomas	aP < 0.05	——	dP < 0.01	dP < 0.01	dP < 0.01
Non-metastatic CRCs	bP < 0.01	dP < 0.01	——	eP < 0.05	fP < 0.01
Metastatic CRCs	bP < 0.01	dP < 0.01	eP < 0.05	——
Regional lymph node metastatic sites	bP < 0.01	dP < 0.01	fP < 0.01		——

Table 4 Correlation between expression of NDRG1 and lymph node metastasis in CRCs

Expression of NDRG1	LN (-)	LN (+)
-	2	0
+	24	14
++	19	18
+++	0	6
P value	< 0.01
Spearman correlation coefficient	0.329

Table 5 Association of clinicopathologic variables with NDRG1 expression in CRCs

	No. of cases	-	+	++	+++
Sex
Male	51	1	26	20	4
Female	32	1	12	17	2
Age (years)
< 55	41	1	18	18	4
≥ 55	42	1	20	19	2
Histological differentiation
High differentiation	23	2	10	11	0
Moderate differentiation	47	0	23	20	4
Poor differentiation	13	0	5	6	2