Table 2. Expression of C4.4A in colorectal, pancreatic and renal cell carcinoma.

(A) Comparison between tumour and non-transformed tissue
		% stained samplesa
Tissue	No. of samples	Negative (−)	Weak (±)	Distinct (+) C4.4A	Strong (++)	Very strong (+++)	P-value§
Colonic mucosa	61	98.4	1.6	0.0	0.0	0.0
Colitis ulcerosa	6	100.0		0.0	0.0	0.0
Colorectal carcinoma	55	7.3	7.3	23.6	32.7	29.1	<0.0001
Liver	35	97.1	2.9	0.0	0.0	0.0
Liver metastasis	38	13.2	7.9	31.6	31.6	15.8	<0.0001
Pancreatic gland	8	62.5	37.5	0	0	0
Chronic pancreatitis	10	40.0	20.0	10.0	20.0	10.0
Pancreatic carcinoma	30	26.7	20.0	40.0	10.0	3.3	0.01
Kidney	10	70.0	30.0	0.0	0.0	0.0
Renal cell carcinoma	61	21.3	21.3	31.1	16.4	9.8	NS

(B) Comparison between different tumour markers
	Marker
Parameter	C4.4A	Galectin-3†	EpCAMb,†	CO-029b,†	UPAR†
Colorectal cancer
No cancer tissue	55	100	100	93
No control tissue	61	100	100	93
Sensitivityc	0.85	0.79 (NS)	0.94 (NS)	0.98 (0.004)
Specificityc	1.00	0.97 (NS)	0.80 (0.0002)	0.94 (0.045)
Liver metastasis
No cancer tissue	38	57	57	54
No control tissue	35	57	57	54
Sensitivity	0.79	0.83 (NS)	0.93 (0.04)	0.94 (0.02)
Specificity	1.00	1.00 (NS)	0.91 (NS)	0.94 (NS)
Pancreatic cancer
No cancer tissue	30	30	30	30	30
No control tissue	8	8	8	8	8
Sensitivity	0.53	0.80 (0.03)	0.87 (0.005)	1.00 (0.00002)	0.67 (NS)
Specificity	1.00	0.75 (NS)	0.13 (0.0004)	0.50 (0.02)	1.00 (NS)
Renal cell carcinoma
No cancer tissue	61				61
No control tissue	10				10
Sensitivity	0.57				0.38 (0.009)
Specificity	1.00				1.00 (NS)

(C) Correlation to colorectal tumour grading and staging
Primary tumour	No. of samples	C4.4A % stained (mean staining intensity)d	P-value+	No. of samples	Galectin-3 % stained (mean staining intensity)d	P-value+
Primary tumour staging
T0–1	4	100 (2.00)	NS	6	100 (1.50)	NS
T2	11	100 (2.50)		22	100 (1.75)
T3	25	84.0 (1.68)		49	91.8 (1.73)
T4	15	100.0 (1.68)		20	95.0 (1.74)
Lymph node staging
N0	35	94.3 (1.51)	NS	61	96.7 (1.66)	NS
N1	12	91.7 (1.90)		23	100.0 (1.77)
N2	8	87.5 (1.42)		13	76.9 (1.55)
Metastasis staging
M0/mix	43	93.0 (1.62)	NS	74	95.6 (1.69)	NS
M1	12	91.7 (1.85)		23	91.3 (1.81)
Primary tumour grading
G0/G1	2	100.0 (2.20)	NS	5	100.0 (1.83)	NS
G2	44	90.9 (1.86)		72	94.4 (1.72)
G3/G4	9	88.9 (1.83)		20	95.0 (1.74)

(D) Correlation to the disease-free survival in colorectal cancer patients
Disease-free survival (months)	No. of samples	C4.4A % stained (mean intensity of staining)d	P-value§§	No. of samples	Galectin-3 % stained (mean intensity of staining)d	P-value§§
Primary tumour
0	13	84.6 (1.86)	NS	26	92.3 (1.81)	NS
Undefined	42	92.9 (1.61)		71	98.8 (1.70)
Liver metastasis
0	11	100 (1.44)	NS	20	90.0 (1.73)	NS
1–24	17	94.1 (1.44)		22	90.9 (1.43)
>24	9	88.9 (1.55)		15	93.3 (1.43)

NS=not significant.

^aMean intensity of staining was estimated as indicated in Materials and Methods; samples classified as − or ± were considered negative, samples classified as +, ++ and +++ were considered as positive.

^bPart of these analyses has already been described (Gesierich et al, 2005; Kuhn et al, 2007).

^cSample with a score of − and ± were considered as negative; samples with a score of +, ++ and +++ were considered as positive; sensitivity=true positive: (true positive + false negative); specificity=true negative: (true negative + false positive).

^dMean intensity of staining was estimated as indicated in material and methods, e.g. a score of ± was taken as 0.5 and a score of +++ as 3.

^§Signed rank test; for pancreatic adenocarcinoma, Wilcoxon rank sum test.

^†P-value=χ²-test.

⁺The correlation between marker expression and tumour staging, lymph node staging, metastasis staging and tumour grading was calculated by the Jonckheere–Terpstra test for trend. No significant differences were observed.

^§§Expression of C4.4A and galectin-3 did not differ significantly (Wilcoxon rank sum test) in primary tumours of patients who had developed liver metastasis concomitantly with the primary tumour of those who had not. In liver metastasis C4.4A and galectin-3 expression did not correlate with the disease-free survival.