Role of serum carcinoembryonic antigen in the detection of colorectal cancer before and after surgical resection

Table 1 Parameters of colorectal cancer patients enrolled in this study (n = 413)

Variable	n (%)
Gender
Male	270 (65.4)
Female	143 (34.6)
Age (yr)
< 40	56 (13.6)
40-60	147 (35.6)
> 60	210 (50.8)
Preoperative S-CEA
≤ 5 ng/mL	260 (63.0)
> 5 ng/mL	153 (37.0)
Location
Colon	174 (42.1)
Rectum	239 (57.9)
Differentiation
Well	281 (32.0)
Poor	132 (68.0)
Size (cm)
≤ 5	275 (66.6)
> 5	134 (32.4)
PT
T1	8 (1.9)
T2	88 (21.3)
T3	229 (55.4)
T4	88 (21.3)
PN
N0	245 (59.3)
N1	108 (26.2)
N2	60 (14.5)
Lymphovascular invasion
Present	23 (5.6)
Absent	390 (94.4)

PT: Pathologic T stage; PN: Pathologic N stage; S-CEA: Serum levels of carcinoembryonic antigen.

Table 2 Correlation between preoperative serum levels of carcinoembryonic antigen levels and clinicopathologic characteristics n (%)

Characteristics	Preoperative S-CEA		P value
	≤5 ng/mL	> 5 ng/mL
Gender
Male	167 (61.9)	103 (38.1)	0.524
Female	93 (65.0)	50 (35.0)
Age (yr)
< 40	35 (62.5)	21 (37.5)	0.178
40-60	101 (68.7)	46 (31.3)
> 60	124 (59.0)	86 (41.0)
Location
Colon	106 (60.9)	68 (39.1)	0.223
Rectum	154 (64.4)	85 (35.6)
Size (cm)
≤ 5	188 (68.4)	87 (31.6)	0.002
> 5	70 (52.2)	64 (47.8)
Differentiation
Well	176 (62.9)	104 (37.1)	0.997
Poor	83 (62.9)	49 (37.1)
PT
T1	8 (100.0)	0 (0.0)	0.005
T2	64 (72.7)	24 (27.3)
T3	141 (61.8)	87 (38.2)
T4	46 (52.3)	42 (47.7)
PN
N0	162 (66.1)	83 (33.9)	0.260
N1	64 (59.3)	44 (40.7)
N2	34 (56.7)	26 (43.3)
Lymphovascular invasion
Present	11 (47.8)	12 (52.2)	0.122
Absent	249 (63.8)	141 (36.2)
TNM stage
I	55 (78.6)	15 (21.4)	0.011
II	107 (61.1)	68 (38.9)
III	98 (58.3)	70 (41.7)

PT: Pathologic T stage; PN: Pathologic N stage; TNM: Tumor Node Metastasis; S-CEA: Serum levels of carcinoembryonic antigen.

Table 3 Multivariate analysis of factors for 5-year disease-free survival rates

Factor	Hazards ratio (CI)	P value
PT	1.448 (1.081-1.940)	0.013
PN	1.624 (1.264-2.088)	0.000
Preoperative S-CEA	1.663 (1.127-2.455)	0.010
Differentiation	1.347 (0.873-2.079)	0.178
Lymphovascular invasion	1.738 (0.890-3.394)	0.105
Lymph nodes evaluated	1.013 (0.780-1.316)	0.925

PT: Pathologic T stage; PN: Pathologic N stage; CI: Confidence interval; S-CEA: Serum levels of carcinoembryonic antigen.

Table 4 Patterns of colorectal cancer recurrence according to serum carcinoembryonic antigen levels n (%)

Patterns of CRC recurrence	CEA levels		P value
	≤5 ng/mL	> 5 ng/mL
Local relapse	26 (63.4)	15 (36.6)
Metastasis (single)	11 (33.3)	22 (66.7)	0.007
Metastases (multiple)	4 (25.0)	12 (75.0)

CEA: Carcinoembryonic antigen; CRC: Colorectal cancer.

Table 5 Correlation between serum carcinoembryonic antigen levels in patients with recurrent colorectal cancer and clinicopathologic characteristics n (%)

Clinicopathologic characteristics	S-CEA levels in patients with recurrent CRC		P value
	≤ 5 ng/mL	> 5 ng/mL
Gender
Male	27 (40.3)	40 (59.7)	0.097
Female	14 (60.9)	9 (39.1)
Age (yr)
≤ 40	7 (53.8)	6 (46.2)	0.805
40-60	13 (43.3)	17 (56.7)
≥ 60	21 (44.7)	26 (55.3)
Preoperative S-CEA
≤ 5 ng/mL	31 (67.4)	15 (32.6)	0.001
> 5 ng/mL	10 (22.7)	34 (77.3)
Location
Colon	17 (44.7)	21 (55.3)	0.894
Rectum	24 (46.2)	28 (53.8)
Differentiation
Well	22 (37.9)	36 (62.1)	0.051
Poor	19 (59.4)	13 (40.6)
PT
T1	0 (0.0)	0 (0.0)	0.438
T2	5 (41.7)	7 (58.3)
T3	19 (40.4)	28 (59.6)
T4	17 (54.8)	14 (45.2)
PN
N0	14 (46.7)	16 (53.3)	0.364
N1	14 (37.8)	23 (62.2)
N2	13 (56.5)	10 (43.5)

CRC: Colorectal cancer; PT: Pathologic T stage; PN: Pathologic N stage; S-CEA: Serum levels of carcinoembryonic antigen.

Table 6 Multivariate analysis of parameters for recurrent colorectal cancer patients using the cox proportional hazards model

Parameter evaluated	Hazards ratio (CI)	P value
Gender	0.49 (0.151-1.607)	0.241
Differentiation	0.42 (0.142-1.245)	0.118
Preoperative S-CEA	0.27 (0.094-0.767)	0.014
Recurrence pattern	0.34 (0.119-0.950)	0.040

CI: Confidence interval; S-CEA: Serum levels of carcinoembryonic antigen.