Microsatellite instability, MMR gene expression and proliferation kinetics in colorectal cancer with famillial predisposition

Table 1 MSI and mean age at onset of colorectal cancer

Group	MSI	n	Age (¯x ± s)
HNPCC		4	41.8 ± 7.7b
A	+	12	45.4 ± 8.3b
	-	14	49.6 ± 9.7
B	+	2	57.5 ± 9.2
	-	18	58.9 ± 11.0

^bP < 0.01 vs Group B; Fisher’s test.

Table 2 MSI and location, histologic differentiation of colorectal cancer

Group	MSI	Location n (%)		Differentiation n (%)
		Pr	Di	PD	WD
A	+	8 (66.7)	4 (33.3)	9 (75.0)b	3 (25.0)
	-	5 (35.7)	9 (64.3)	4 (28.6)	10 (71.4)
B	+	1 (50.0)	1 (50.0)	2	0
	-	4 (22.2)	14 (77.8)	5 (27.8)	13 (72.2)
Total	+	9 (64.3)a	5 (35.7)	11 (78.6)a	3 (21.4)
	-	9 (28.1)	23 (71.9)	9 (28.1)	23 (71.9)

^aP < 0.05, vs patients negative for MSI; χ² test.

^bP < 0.05, vs patients negative for MSI in Group A; χ² test. Pr: proximal colon; Di: distal colon (descending, sigmoid colon and rectum); PD: poorly differentiated adenocarcinoma; WD: well and moderately differentiated adenocarcinoma.

Table 3 Negative for hMLH1, hMSH2 protein staining in CRC patients’ tissues (n, %)

	Group A (26 cases)		Group B (20 cases)
	Tumor	Normal	Tumor	Normal
hMLH1 -	16 (61.5)a	17 (65.4)b	6 (30.0)	5 (25.0)
hMSH2 -	14 (53.9)	16 (61.5)b	9 (45.0)	6 (30.0)

^aP < 0.05, vs tumor tissues in Group B; χ² test.

^bP < 0.05, vs normal tissues in Group B; χ² test.

Table 4 MSI and DNA analysis in CRC tumor cells by flow cytometry (¯x ± s)

Group	Cases	Heteroploid (n, %)	PI	S-phase
HNPCC	4	1 (25.0)	14.58 ± 3.12	8.70 ± 1.18
A	26	6 (23.1)a	17.57 ± 6.51	9.47 ± 2.85
B	18	10 (55.6)	17.94 ± 7.51	10.38 ± 3.89
MSI +	14	4 (28.6)	14.34 ± 5.49b	8.18 ± 2.55b
MSI -	30	12 (40.0)	19.30 ± 6.93	10.62 ± 3.36

^aP < 0.05, vs tumor cells in Group B; Fisher’s test.

^bP < 0.05, vs tumor cells negative for MSI; Fisher’s test.