Size does not determine the grade of malignancy of early invasive colorectal cancer

Table 1 Comparison of clinicopathological and endoscopic characteristics for 583 study cases

	Small (≤ 10 mm)	Large (> 10 mm)	P value
No. of lesions, n (%)	120 (21)	463 (79)
Gender (M/F)	85/35	289/174	0.09
Age (yr), mean (range)	61.5 (39-84)	62.4 (30-90)	0.86
Macroscopic type, n (%)
Sessile (0-Is, Is+IIa)	51 (42)	233 (50)	0.13
Flat (0-IIa)	14 (12)	64 (14)
Depressed (0-IIc, IIa+IIc, Is+IIc)	55 (46)	166 (36)
Size (mm), mean ± SD	8.3 ± 1.6	22.1 ± 9.6
Growth pattern (PG/NPG)	38/82	250/213	< 0.0001
Location, n (%)
Rectum	33 (27)	213 (46)	0.02
Distal colon1	56 (47)	139 (30)
Proximal colon2	31 (26)	111 (24)

¹Descending-sigmoid colon;

²Cecum-transverse colon.

Table 2 Incidence of LNM and clinicopathological characteristics based on tumor size n (%)

	Small (≤ 10 mm)	Large (> 10 mm)	P value
LNM	10/89 (11.2)	46/381 (12.1)	0.85
Depth of invasion
sm-superficial (< 1000 &mgr;m)	30 (25)	83 (18)	0.08
sm-deep (≥ 1000 &mgr;m)	90 (75)	380 (82)
LVI	26 (22)	125 (27)	0.23
PDA	12 (10)	79 (17)	0.06

LVI: Lymphovascular invasion; PDA: Poorly differentiated adenocarcinoma; LNM: Lymph node metastasis.

Table 3 Comparison of treatment strategy and positive rate of cut margin n (%)

	Small (≤ 10 mm)	Large (> 10 mm)	P value
Initial treatment
EMR	62 (52)	133 (29)	< 0.0001
Surgery	58 (48)	330 (71)
Positive rate of cut margin1	11 (18)	26 (20)	0.81
In EMR cases
Lateral	0 (0)	8 (31)	0.08
Vertical	11 (100)	18 (69)

¹Positive and unknown cut margin. EMR: Endoscopic mucosal resection.

Table 4 Comparison of clinicopathological characteristics and incidence of LNM based on the treatment strategy n (%)

	EMR (n = 195)	Surgery (n = 388)	P value
Depth of invasion
sm-superficial (< 1000 &mgr;m)	61 (32)	52 (13)	< 0.0001
sm-deep (≥ 1000 &mgr;m)	134 (69)	336 (87)
LVI	33 (17)	118 (30)	0.0006
PDA	18 (9)	73 (19)	0.0006
Positive rate of cut margin1	37 (19)	0 (0)	< 0.0001
Lateral	8 (22)	0 (0)
Vertical	29 (78)	0 (0)
Additional surgical operation	82 (42)	-
LNM	9/82 (11.0)	47/388 (12.1)	0.79

¹Positive and unknown cut margin.