Patterns of lymph node metastasis are different in colon and rectal carcinomas

Table 1 Comparison between rectal cancer and colon cancer groups n (%)

Clinicopathologic factors	Rectal cancer (n = 1314)	Colon cancer (n = 1026)	P value
Gender
Male	797 (60.7)	566 (55.2)	0.008
Female	517 (39.3)	460 (44.8)
Age (yr)	59 (50-68)	64 (53-72)	< 0.001
Grade
Low	1125 (85.6)	830 (80.9)	0.002
High	189 (14.4)	196 (19.1)
Tumor size (cm)	4.0 (3.0-5.5)	5.0 (4.0-6.0)	< 0.001
Total nodes	9 (7-12)	10 (8-13)	< 0.001
Positive nodes	3 (1-5) (n = 544)	2 (1-4) (n = 364)	< 0.001
LNR	0.31 (0.14-0.60) (n = 544)	0.22 (0.13-0.50) (n = 364)	< 0.001
N stage
N0	770 (58.6)	662 (64.5)	< 0.001
N1	338 (25.7)	267 (26.0)
N2	206 (15.7)	97 (9.5)
N+ stage
N0	770 (58.6)	662 (64.5)	0.004
N+	544 (41.4)	364 (35.5)
T stage
T1	49 (3.7)	23 (2.2)	< 0.001
T2	377 (28.7)	121 (11.8)
T3-4	888 (67.6)	882 (86.0)

LNR: Lymph node ratio.

Table 2 Comparison between the percentage of patients with N+ stage

T stage1	N+ stage proportion (%)		P value
	Rectal cancer (n = 1314)	Colon cancer (n = 1026)
T1	5/49 (10.2)	1/23 (4.3)	< 0.001
T2	84/377 (22.3)	23/121 (19.0)
T3-4	455/888 (51.2)	340/882 (38.5)

¹Stratified by T stage.