Table 1. Clinical characteristics by CEA status.

	Group A (n = 152)	Group B (n = 69)	Group C (n = 52)	p
Sex
Male	80 (53%)	36 (52%)	33 (53%)	0.239
Female	72 (47%)	33 (48%)	19 (37%)
Age (years), median (range)	70 (32–93)	69 (28–89)	72 (53–88)	0.493
Tumor location
Right colon	52 (34%)	22 (32%)	25 (48%)	0.222
Left colon	59 (39%)	24 (35%)	18 (35%)
Rectum	41 (27%)	23 (33%)	9 (17%)
Preoperative CEA levels (ng/mL), median (range)	2.6 (0.6–4.9)	8.6 (5.0–97.1)	8.9 (2.8–263.5)	< 0.001
Postoperative CEA levels (ng/mL), median (range)	2.2 (0.5–4.9)	2.6 (0.8–4.7)	6.4 (5.1–84.9)	< 0.001
T Stage
T1	22 (14%)	2 (3%)	2 (3%)	< 0.001
T2	32 (21%)	4 (6%)	5 (10%)
T3	94 (62%)	60 (87%)	39 (75%)
T4	4 (3%)	3 (4%)	6 (12%)
N Stage
N0	109 (72%)	34 (49%)	26 (50%)	0.002
N1	33 (22%)	21 (31%)	19 (37%)
N2	10 (6%)	14 (20%)	7 (13%)
TNM stage
I	47 (31%)	5 (7%)	7 (13%)	< 0.001
II	62 (41%)	29 (42%)	19 (37%)
III	43 (28%)	35 (51%)	26 (50%)
Differentiation
Well	6 (4%)	0	4 (8%)	0.210
Moderately	142 (93%)	68 (99%)	46 (88%)
Poorly	4 (3%)	1 (1%)	2 (4%)
LVI
Yes	90 (59%)	42 (61%)	31 (60%)	0.973
No	62 (41%)	27 (39%)	21 (40%)
PNI
Yes	18 (12%)	11 (16%)	6 (12%)	0.667
No	134 (88%)	58 (84%)	46 (88%)
Chemotherapy regimen
FOLFOX	54 (36%)	36 (52%)	16 (31%)	< 0.001
XELOX	0 (0%)	2 (3%)	0 (0%)
UFUR	35 (23%)	19 (28%)	18 (34%)
Capecitabine	0 (0%)	0 (0%)	2 (4%)
No	63 (41%)	12 (17%)	16 (31%)
Smoking
Yes	36 (24%)	14 (20%)	24 (46%)	0.002
No	116 (76%)	55 (80%)	28 (54%)

Data are presented as n (%), unless otherwise indicated.

PNI, perineural invasion; LVI, lymphovascular invasion; TNM, tumor-node-metastasis