Importance of histological evaluation in endoscopic resection of early colorectal cancer

Table 1 The differences in the histopathological diagnosis of colorectal intraepithelial tumors between Japan and Western countries

	Intramucosal epithelial tumor
Japan	Low grade adenoma	High grade adenoma	Intramucosal adenocarcinoma
United Kingdom	Mild dysplasia	Moderate dysplasia	Severe dysplasia
United States	Low grade dysplasia		High grade dysplasia

Table 2 The rates of en bloc resection and local recurrence of tumors larger than 20 mm in diameter treated by endoscopic mucosal resection

Author	Injection solution	No. of cases	Rate of en bloc resection (%)	Rate of local recurrence (%)
Saito et al[18]		228	33.0	14
Tanaka et al[19]	Glycerol	178	39.3	7.9
Tajika et al[20]		104	48.1	15.4
Iishi et al[21]	NS	56	25.0	-
Kobayashi et al[22]		56	37.5	21.4
Uraoka et al[23]	NS	44	20.5	18.6
	Glycerol	39	23.1	15.2
Our data	HA	35	42.8	10

HA: Hyaluronic acid; NS: Not significant.

Table 3 The rates of en bloc resection and complete resection by endoscopic submucosal dissection

Author	No. of cases	Rate of en bloc resection (%)	Perforation rate (%)	Post-operative bleeding rate (%)
Saito et al[7]	1111	88.0	4.9	1.5
Toyonaga et al[32]	468	98.9	1.5	1.5
Isomoto et al[33]	292	90.1	8.2	0.7
Yoshida et al[34]	250	86.8	6.0	2.4
Fujishiro et al[35]	200	91.5	10.4	1.0
Zhou et al[36]	74	93.2	8.1	1.3
Tanaka et al[37]	70	80.0	10.0	1.4
Our recent data	410	92.6	4.1	1.9

Table 4 Characteristics of colorectal tumors resected by endoscopic submucosal dissection

	SM	M	A	Pvalue
Number of tumors	33	144	157
Median age (yr) (range)	65.5 (46-83)	67.9 (48-87)	67.5 (39-87)
Male/female	21/12	86/58	81/76	NS
Tumor size (mm) (range)	26.5 (10-60)	35.1 (10-130)	27.0 (10-80)	P < 0.01
Location (colon/ rectum)	18:15	87:57	124:33	P < 0.01 SM:A
Morphology (protruding/ superficial)	14:19	32:112	12:145	P < 0.01
Operation time (min) (range)	109 (20-240)	118 (30-420)	92 (10-300)	NS
Severe Fibrosis (%)	18.1	5.5	6.3	P < 0.05 SM:M
En bloc resection (%)	90.9	90.9	89.1	NS
Complete resection (%)	72.7	84	81.5	NS
Perforation (%)	6	7.6	1.9	NS
Postoperative hemorrhage (%)	0	6.2	1.2	NS

ESD: Endoscopic submucosal dissection; SM: Submucosally invasive cancer; M: Intramucosal cancer; A: Adenoma; NS: Not significant.

Table 5 Characteristics of submucosally invasive cancer resected by endoscopic submucosal dissection

	SM1	SM2-3	Pvalue
Number of tumors	13	20
Tumor size (mm) (range)	30.7 (20-60)	23.7 (10-60)	NS
Location	8:5	10:10	NS
(colon/ rectum)
Morphology (Is, Isp/ IIa, IIc, IIa + IIc)	4:9	10:10	NS
Operation time (min) (range)	121 (50-240)	98 (20-230)	NS
Severe fibrosis (%)	15.3	20	NS
En bloc resection (%)	90.9	89.1	NS
Venous invasion (%)	1 (7.6)	6 (30.0)	NS
Lymphatic invasion (%)	2 (15.3)	4 (20.0)	NS
Positive of horizontal margin (%)	3 (23.0)	3 (15.0)	NS
Positive of vertical margin (%)	1 (7.6)	4 (20.0)	NS
Perforation (%)	7.6	1.9	NS

SM: Submucosally invasive cancer.