MUC5AC/β-catenin expression and KRAS gene alteration in laterally spreading colorectal tumors

Table 1 Clinicopathological characteristics of laterally spreading tumor of the colorectum

Variable	Gr-type (n = 36)	NGr-type (n = 33)
Age (yr)	68.5 ± 10.9 (34-88)	69.0 ± 10.3 (44-85)
Sex
Male	21	23
Female	15	10
Location
Proximal colon	18	12
Distal colon	18	21
Size of tumor (mm)	35.3 ± 17.9 (12-80)b	23.0 ± 9.1 (10-50)b
Histology
LGD	15	12
Tubular type	11	11
Tubulovillous type	4	1
HGD	12	14
Tubular typed	0	13
Tubulovillous typed	12	1
INV	9	7
Well differentiated type	7	7
Others	2	0

Age and size of tumor are represented as mean ± SD (range); Gr-type: Granular type of laterally spreading tumor; NGr-type: Flat- or non-granular type of laterally spreading tumor; LGD: Adenoma with low grade dysplasia; HGD: Adenoma with high grade dysplasia; INV: Adenocarcinoma invading submucosa; INV-others: Mixed well and moderately differentiated type (n = 1) and mixed well and poorly differentiated adenocarcinoma (n = 1); ^b,dP < 0.01, Gr-type vs NGr-type, tubular type vs tubulovillous type.

Table 2 Correlations among expression levels of the encoded proteins

	MUC5AC		MUC6		CD10		p53		Nuclearβ-catenin		Ki-67
	Gr-type	NGr-type	Gr-type	NGr-type	Gr-type	NGr-type	Gr-type	NGr-type	Gr-type	NGr-type	Gr-type
MUC2	0.550b	0.486b	NS	NS	-0.417a	NS	-0.549a	-0.450a	NS	0.413a	-0.397a
MUC5AC	Blank		NS	NS	NS	NS	-0.430a	-0.368a	-0.334a	NS	NS
MUC6	Blank		Blank		NS	NS	NS	NS	NS	NS	NS
CD10	Blank		Blank		Blank		NS	NS	NS	NS	NS
p53	Blank		Blank		Blank		Blank		NS	NS	0.514b
Nuclear β-catenin	Blank		Blank		Blank		Blank		Blank		NS

Gr-type: Granular type of laterally spreading tumor; NGr-type: Flat- or non-granular type of laterally spreading tumor; Data indicates rho value examined by Spearman’s correlation coefficient; NS: Not significant.

^aP < 0.05;

^bP < 0.01.

Table 3 Frequency of KRAS and BRAF mutations in laterally spreading tumor of the colorectum

Type of tumors	Number (%) of mutated samples
	All			Proximal colon
	n	KRAS	BRAF	n	KRAS
Gr-type	29	15 (52)a	2 (7)	13	9 (69)c
LGD	10	6 (60)	0 (0)	7	6 (86)d,e
HGD	10	6 (60)b	1 (10)	3	2 (67)
INV	9	3 (33)	1 (11)	3	1 (33)
NGr-type	27	2 (7)a	0 (0)	18	1 (6)c
LGD	10	1 (10)	0 (0)	8	1 (13)d
HGD	10	0 (0)b	0 (0)	8	0 (0)
INV	7	1 (14)	0 (0)	2	0 (0)
Total	56	17 (30)	2 (4)	30	10 (33)

Gr-type: Granular type of laterally spreading tumor; NGr-type: Flat- or non-granular type of laterally spreading tumor; LGD: Adenoma with low grade dysplasia; HGD: Adenoma with high grade dysplasia; INV: Adenocarcinoma invading submucosa; KRAS: v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog; BRAF: v-raf murine sarcoma viral oncogene homologue B1. ^{a, c, e}P < 0.05, All and proximal colon: Gr-type vs NGr-type; Gr-LGD: proximal vs distal colon; ^{b, d}P < 0.01, all and proximal colon: Gr-HGD vs NGr-HGD; proximal colon: Gr-type vs NGr-type.