Loss of CDX2 expression is associated with poor prognosis in colorectal cancer patients

Table 1 Expression of CK7, CK20 and CDX2 in colorectal cancers according to CpG island methylator phenotype and microsatellite instability status

	CIMP			MSI
	CIMP-0, low	CIMP-high	P value1	MSS, MSI-low	MSI-high	P value1
CK7	5.7 ± 20.5	18.7 ± 37.5	0.004	6.0 ± 21.2	12.6 ± 30.7	0.082
CK20	83.5 ± 26.4	69.2 ± 37.3	0.022	84.8 ± 25.0	58.9 ± 39.1	< 0.001
CDX2 (CDX2-88)	87.7 ± 20.1	48.3 ± 42.4	< 0.001	86.8 ± 21.8	67.3 ± 38.3	< 0.001
CDX2 (EPR2764Y)	95.6 ± 19.1	56.7 ± 47.8	< 0.001	93.8 ± 22.8	85.5 ± 33.8	0.036

¹Wilcoxon’s rank-sum test. CIMP: CpG island methylator phenotype; MSI: Microsatellite instability; MSS: Microsatellite stable; CK: Cytokeratin.

Table 2 Clinicopathologic characteristics of colorectal cancer patients with loss of CDX2 expression n (%)

Parameters	CDX2-retained671 (94.1)	Loss of CDX2 expression42 (5.9)	P value
Age (median)	60.9 ± 11.5	62.2 ± 12.1	0.5031
Sex			0.070
Male	414 (61.7)	20 (47.6)
Female	257 (38.1)	22 (52.4)
Location			< 0.001
Proximal colon	166 (24.7)	25 (59.5)
Distal colon	276 (41.1)	10 (23.8)
Rectum	229 (34.1)	7 (16.7)
Gross type			0.009
Fungating	451 (67.2)	20 (47.6)
Ulcerative	220 (32.8)	22 (52.4)
T category			0.005
T1, 2	135 (20.1)	1 (2.4)
T3, 4	536 (79.9)	41 (97.6)
N category			< 0.001
N0	355 (52.9)	10 (23.8)
N1, 2	316 (47.1)	32 (76.2)
M category			0.039
M0	562 (83.8)	30 (71.4)
M1	109 (16.2)	12 (28.6)
Stage			< 0.001
I, II	331 (49.3)	9 (21.4)
III, IV	340 (50.7)	33 (78.6)
Adjuvant chemotherapy			0.854
Not treated	233 (34.7)	14 (33.3)
Treated	438 (65.3)	28 (66.7)

¹Student’s t test. HPF: High power field. Cut-off for loss of CDX2 expression: < 20% of tumor cells showing nuclear positivity.

Table 3 Histologic features of colorectal cancers in patients with loss of CDX2 expression n (%)

Parameters	CDX2-retained671 (94.1)	Loss of CDX2 expression42 (5.9)	P value
Differentiation			< 0.0011
Differentiated	656 (97.8)	31 (73.8)
Undifferentiated	15 (2.2)	11 (26.2)
Luminal necrosis			0.0531
Absent	61 (9.1)	8 (19.1)
Present	610 (90.9)	34 (80.9)
Tumor budding			> 0.9991
Absent	29 (4.3)	1 (2.4)
Present	642 (95.7)	41 (97.6)
Tumor-infiltrating lymphocytes			0.013
Low (< 8/HPF)	513 (76.4)	25 (59.5)
High (≥ 8/HPF)	158 (23.6)	17 (40.5)
Crohn’s-like lymphoid reaction			< 0.0011
Absent	552 (82.3)	32 (76.2)
Present	119 (17.7)	10 (23.8)
Luminal serration			< 0.0011
Absent	641 (95.5)	32 (7.2)
Present	30 (4.5)	10 (23.8)
Mucin production			0.016
Absent	595 (88.7)	32 (76.2)
Present	76 (11.3)	10 (23.8)

¹Fisher’s exact test.

Table 4 Comparison of molecular characteristics of colorectal cancers with and without CDX2 expression n (%)

Parameters	CDX2-retained671 (94.1)	Loss of CDX2 expression42 (5.9)	P value
CIMP			< 0.001
CIMP-0	271 (40.4)	5 (11.9)
CIMP-low	374 (55.7)	17 (40.5)
CIMP-high	26 (3.9)	20 (47.6)
MSI			< 0.001
MSS	587 (87.5)	28 (66.7)
MSI-low	35 (5.2)	2 (4.7)
MSI-high	49 (7.3)	12 (28.6)
KRAS (n = 674)			0.577
Wild type	466 (73.5)	31 (77.5)
Mutant type	168 (26.5)	9 (22.2)
BRAF (n = 707)			0.0051
Wild type	634 (95.2)	34 (82.9)
Mutant type	32 (4.8)	7 (17.1)
CK7 expression			< 0.0011
No-expression	624 (93.0)	24 (57.1)
Increased	47 (7.0)	18 (42.9)
CK20 expression			< 0.001
Retained	593 (88.4)	27 (64.3)
Decreased	78 (11.6)	15 (35.7)

¹Fisher’s exact test. Cut-off for increased CK7 expression: ≥ 10% of tumor cells showing membranous stain, cut-off for decreased CK20 expression: < 50% of tumor cells showing membranous stain. CIMP: CpG island methylator phenotype; MSI: Microsatellite instability; MSS: Microsatellite stable; CK: Cytokeratin.

Table 5 Multivariate logistic regression analysis of independent relations with loss of CDX2 expression in colorectal cancers

Variables	OR (95%CI)	P value
Differentiation (differentiated/ undifferentiated)	4.98 (1.42-17.49)	0.012
CK7 expression (expression/ no-expression)	11.21 (4.64-27.11)	< 0.001
CK20 expression (loss/retained)	2.90 (1.08-7.77)	0.034
CIMP (CIMP-high/CIMP-0, low)	7.78 (2.85-21.23)	< 0.001
Tumor location (proximal/distal, rectum)	1.83 (0.79-4.26)	0.162
Gross type (infiltrative/fungating)	1.67 (0.74-3.81)	0.220
T category (T1, 2/T3, 4)	3.66 (0.44-30.17)	0.229
N category (N0/N1, 2)	1.77 (0.69-4.53)	0.233
M category (M0/M1)	1.69 (0.62-4.62)	0.310
MSI (MSI-high/MSS, MSI-low)	1.55 (0.51-4.75)	0.441
BRAF mutation (Mt/Wt)	3.13 (0.95-10.37)	0.062

CIMP: CpG island methylator phenotype; MSI: Microsatellite instability; MSS: Microsatellite stable; Mt: Mutant type; Wt: Wild type; CK: Cytokeratin.

Table 6 Univariate and multivariate progression-free survival in colorectal cancer patients

Variables	Univariate analysis		Multivariate analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Gross pattern	1.96 (1.53-2.50)	< 0.001	1.54 (1.20-1.98)	0.001
(infiltrative/fungating)
Stage	4.59 (3.40-6.19)	< 0.001	4.11 (3.04-5.57)	< 0.001
(III, IV/I, II)
Differentiation	3.43 (2.12-5.54)	< 0.001	1.57 (0.92-2.70)	0.100
(undifferentiated/differentiated)
CDX2 expression	2.99 (2.02-4.43)	< 0.001	1.94 (1.22-3.07)	0.005
(loss/retained)
CIMP	1.84 (1.21-2.80)	0.004	1.03 (0.64-1.67)	0.892
(CIMP-high/CIMP-0, low)
Age (yr)	1.17 (0.91-1.49)	0.223
(≥ 65/< 65)
Sex	1.03 (0.81-1.33)	0.794
(female/male)
Tumor location	1.16 (0.89-1.53)	0.269
(proximal colon/distal colon, rectum)
Adjuvant chemotherapy	1.14 (0.88-1.49)	0.449
(treatment/no-treatment)
CK7 expression	0.88 (0.56-1.37)	0.571
(increased/no-expression)
CK20 expression	1.00 (0.70-1.45)	0.986
(decreased/retained)
MSI	0.81 (0.49-1.32)	0.395
(MSI-high/MSS, MSI-low)
KRAS mutation	0.98 (0.74-1.31)	0.914
(Mt/Wt)
BRAF mutation	1.17 (0.69-1.96)	0.567
(Mt/Wt)

CIMP: CpG island methylator phenotype; MSI: Microsatellite instability; MSS: Microsatellite stable; Mt: Mutant type; Wt: Wild type; CK: Cytokeratin.