Table 2. Patient and tumour characteristics according to CDX2 expression (positive or negative) in mCRC.

Patient and tumour characteristics	Patients with analysed CDX2 expression	CDX2 expression status		CDX2 status comparison
		Negative CDX2	Positive CDX2	p value
Total number	346	27 (7.8%)	319 (92.2%)
Median age at diagnosis of metastatic disease (95% CI)	59.7 (30–88)	58.7 (34–86)	59.7 (30–88)	1.00a
Male	185 (53.5%)	14 (8%)	171 (92%)	1.00a
Female	161 (46.5%)	13 (8%)	148 (92%)
Histology	319	23 (7.2%)	296 (92.8%)
Tumour grade 1 (Well differentiated)	25 (7.8%)	3 (12%)	22 (88%)	0.007a
Tumour grade 2 (Mod. differentiated)	264 (82.8%)	14 (5.3%)	250 (94.7%)
Tumour grade 3 (Poorly differentiated)	30 (9.4%)	6 (20%)	24 (80%)
Tumour sidedness	344	27 (7.8%)	317 (92.2%)
Right sided	87 (25.3%)	10 (11.5%)	77 (88.5%)	0.187a
Left sided/Rectum	257 (74.7%)	17 (6.6%)	240 (93.4%)
Tumour genetics
BRAF	180	14 (7.8%)	166 (92.2%)
Wild-type	165 (91.7%)	8 (4.8%)	157 (95.2%)	0.0002a
p.V600E variant	15 (8.3%)	6 (40%)	9 (60%)
KRAS or NRAS	346	27 (7.8%)	319 (92.2%)
Wild-type	178 (51.4%)	15 (8.4%)	163 (91.6%)	0.807a
Mutated	168 (48.6%)	12 (7.1%)	156 (92.9%)
MMR	279	15 (5.4%)	264 (94.6%)
MSS	270 (96.8%)	14 (5.2%)	256 (94.8%)	0.396a
High MSI	9 (3.2%)	1 (11.1%)	8 (88.9%)
Sites of metastasis at diagnosis	346	27 (7.8%)	319 (92.2%)
Liver	153 (44.2%)	12 (7.8%)	141 (92.2%)	0.287a
Peritoneum	74 (21.4%)	8 (10.8%)	66 (89.2%)
Lung	59 (17.1%)	1 (1.7%)	58 (98.3%)
Non regional lymph nodes	34 (9.8%)	3 (8.8%)	31 (91.2%)
Bone	2 (0.6%)	0	2 (100%)
Other	24 (6.9%)	3 (12.5%)	21 (87.5%)

Data presented as n (%)

^aChi-square test

MMR: mismatch repair; MSS: microsatellite stability; MSI: microsatellite instability