Immunohistochemical expression of mismatch repair genes: A screening tool for predicting mutator phenotype in liver fluke infection-associated intrahepatic cholangiocarcinoma

Table 1 Immunohistochemical expression of hMSH2 and hMLH1 genes and microsatellite profile in ICC cases analyzed

Case	Age/sex	Histology	pTMNstage	MSphenotype	hMSH2	hMLH1
1	50/M	G3	IVA	o	+	+
2	60/F	G2	IIIB	o	+	+
3	60/F	G2	IVA	o	+	+
4	55/F	G2	IVB	MSI (D17S250)	+	+
5	57/M	G3	IVA	o	+	+
6	71/M	G2	IIIB	o	+	+
7	65/F	G3	IIIA	MSI (D2S123)	-	- *
8	41/F	G1	II	MSI (D2S123)	-	+
9	60/M	G2	IIIB	o	-	+
10	57/M	G2	IVA	MSI (D17S250)	+	+
11	55/M	G2	U	o	+	+
12	55/M	GX	IVB	MSI (D2S123)	+	+
13	54/M	G1	IVA	o	+	+
14	59/F	G2	IVB	o	+	+
15	45/F	G3	IVB	o	+	+
16	42/M	G2	IIIB	o	+	+
17	57/M	G1	IIIA	MSI (D2S123)	-	+
18	51/F	GX	IVB	MSI (BAT-25)	+	+
19	42/M	G2	II	o	+	-
20	51/M	G3	IIIA	o	+	+
21	59/M	G3	IVA	MSI (D2S123)	+	+
22	66/M	G3	IVB	o	+	+
23	64/F	G3	IVA	o	+	+
24	66/M	G1	II	o	+	+
25	42/M	G2	IVB	o	+	+
26	37/F	G3	II	N	+	+
27	57/M	G1	III	N	+	+
28	66/M	G2	IVB	o	+	+
29	52/M	G3	IVB	o	+	+

G1: well differentiated; G2: moderately differentiated; G3: poorly differentiated; GX: grade cannot be assessed; U: not known; M: male; F: female; +: positive nuclear staining; -: negative nuclear staining; MSI: microsatellite instability; o: microsatellite stable; N: MSI status was not available; *: harbouring LOH at D3S1298 and D3S1561.

Table 2 Correlation between hMSH2 and hMLH1 immunohistochemical expression and microsatellite profile in ICC studied n(%)

MSstatus	Numberof cases	Pattern of nuclear expression/n (%)
		hMSH2+hMLH1-	hMSH2-hMLH1+	hMSH2+hMLH1+	hMSH2-hMLH1-
MSI	8	0 (0)	2 (25)	5 (62.5)	1 (12.5)
MSS	19	1 (5.3)	1 (5.3)	17 (89.5)	0 (0)
NP	2	0 (0)	0 (0)	2 (100)	0 (0)
Total	29	1 (3.4)	3 (10.3)	24 (82.8)	1 (3.4)

MSI: Microsatellite instability; MSS: Microsatellite stable; NP: MSI assessment was not performed.