Increased frequency and clinical significance of myeloid-derived suppressor cells in human colorectal carcinoma

Table 1 Correlations between myeloid-derived suppressor cells percentages and colorectal carcinoma clinical parameters

Clinical parameters	Cases	MDSC proportion in peripheral blood			MDSC proportion in CRC tumor tissues
		Low	High	P value	Low	High	P value
Gender				0.252			1.000
Male	26	14	12		12	14
Female	23	8	15		11	12
Age (yr)				0.229			0.292
< 60	16	5	11		8	18
≥ 60	33	17	16		15	18
Tumor size (cm)				1.000			0.571
≤ 5	24	11	13		10	14
> 5	25	11	14		13	12
Tumor (T) status1				0.179			0.466
pT1	4	2	2		1	3
pT2	10	6	4		5	5
pT3	12	9	5		4	8
pT4	23	7	16		13	10
Nodal (N) status2				0.248			0.016a
N0	31	16	15		19	12
N1	18	6	12		4	14
Distant metastasis (M)3				0.023a			0.047a
M0	22	14	8		14	8
M1	27	8	19		9	18
TNM stage				0.207			0.028a
I	6	2	4		2	4
II	12	7	5		8	4
III	11	7	4		8	3
IV	20	6	14		5	15
Total	49	22	27		23	26

¹Tumor status is classified as: pT₁, invasion of lamina propria or submucosa; pT₂, invasion of muscularis propria; pT₃, invasion of adventitia; pT₄, invasion of adjacent structures;

²Nodal status is classified as: N₀, no regional lymph-node metastasis; N₁, regional lymph-node metastasis;

³Distant metastasis is classified as follows: M₀, no distant metastasis; M₁, metastasis to cervical nodes, celiac nodes, and other distant metastases.

^aP < 0.05 was considered statistically significant. MDSC: Myeloid-derived suppressor cells; CRC: Colorectal carcinoma; TNM: Tumor, nodes, metastasis.