Potential of six-transmembrane epithelial antigen of the prostate 4 as a prognostic marker for colorectal cancer

Table 1 Expression of six-transmembrane epithelial antigen of the prostate 4 in colorectal cancer and normal tissues

	Case (n)	STEAP4		χ2	P value
		Low	High
Tumor	87	42 (48.3%)	45 (51.7%)	8.866	0.003a
Normal	87	23 (26.4%)	64 (73.6%)

^aP < 0.05.

STEAP4: Six-transmembrane epithelial antigen of the prostate 4.

Table 2 Correlation between six-transmembrane epithelial antigen of the prostate 4 expression and clinicopathological parameters in colorectal cancer patients

Clinical parameter	STEAP4		P value
	Low (%)	High (%)
Gender
Female	29 (59.2)	20 (40.8)	0.123
Male	19 (43.2)	25 (56.8)
Primary tumor stage1
T1-T3	36 (48.0)	39 (52.0)	0.213
T4a-T4b	11 (64.7)	6 (35.3)
Lymph node status
N0-N1	41 (48.8)	43 (51.2)	0.160
N2	7 (77.8)	2 (22.2)
AJCC stage
Phase 1-2	28 (43.1)	30 (56.9)	0.407
Phase 3	20 (57.1)	15 (42.9)

¹One colorectal cancer patient with undetected primary tumor (Tx) was excluded from the primary tumor stage.

STEAP4: Six-transmembrane epithelial antigen of the prostate 4; AJCC: American Joint Committee on Cancer.

Table 3 Correlation of six-transmembrane epithelial antigen of the prostate 4 expression with MLH1/2/6, PMS2, and programmed death ligand 1 expression in colorectal cancer

		STEAP4		χ2	P value
		Low	High
MLH1	Low	6	5	18.42	0.000004a
	High	33	36
MLH2	Low	18	10	3.90	0.071
	High	21	30
MLH6	Low	8	7	13.44	0.0003a
	High	29	33
PMS2	Low	12	8	10.31	0.017b
	High	27	30
PDL1	Low	43	41	35.37	0.0019c
	High	2	4

^aP < 0.001.

^bP < 0.05.

^cP < 0.01.

PDL1: Programmed death ligand 1; STEAP4: Six-transmembrane epithelial antigen of the prostate 4.