Prognostic value of changes in serum carcinoembryonic antigen levels for preoperative chemoradiotherapy response in locally advanced rectal cancer

Table 3 Comparison of the changes in the carcinoembryonic antigen level before and after chemoradiotherapy

Variables	Group A (n = 27)	Group B (n = 43)	Group C (n = 65)	P value
Age, yr				> 0.999
< 65	17 (63.0%)	27 (62.8%)	41 (63.1%)
≥ 65	10 (37.0%)	16 (37.2%)	24 (36.9%)
Sex				0.358
Male	21 (77.8%)	34 (79.1%)	44 (67.7%)
Female	6 (22.2%)	9 (20.9%)	21 (32.3%)
ASA				0.734
< 3	23 (85.2%)	38 (88.4%)	59 (90.8%)
≥ 3	4 (14.8%)	5 (11.6%)	6 (9.2%)
Pre-CRT tumor size (cm)	4.6 (3.7-5.0)	4.5 (4.0-5.1)	4.3 (3.8-5.0)	0.515
Pre-CRT CEA (ng/mL)	25.8 (10.6-70.7)	11.3 (6.8-21.3)	2.4 (1.8-3.3)	< 0.001
Pre-CRT NLR				0.983
< 2.8	17 (63.0%)	28 (65.1%)	42 (64.6%)
≥ 2.8	10 (37.0%)	15 (34.9%)	23 (35.4%)
Pre-CRT PLR				0.132
< 138.2	11 (40.7%)	19 (44.2%)	39 (60.0%)
≥ 138.2	16 (59.3%)	24 (55.8%)	26 (40.0%)
Pre-CRT T stage				0.217
T3	18 (66.7%)	34 (79.1%)	54 (83.1%)
T4	9 (33.3%)	9 (20.9%)	11 (16.9%)
Pre-CRT N stage				0.021
N0	1 (3.7%)	1 (2.3%)	11 (16.9%)
N+	26 (96.3%)	42 (97.7%)	54 (83.1%)
Pre-CRT TNM stage				0.021
I	1 (3.7%)	0	0
II	1 (3.7%)	1 (2.3%)	11 (16.9%)
III	25 (92.6%)	42 (97.7%)	54 (83.1%)
Post-CRT CEA (ng/dL)	8.4 (6.0–13.7)	2.9 (2.0–4.0)	1.8 (1.2–2.9)	< 0.001
Post-CRT T stage				0.001
0–2	3 (11.1%)	5 (11.6%)	25 (38.5%)
3–4	24 (88.9%)	38 (88.4%)	40 (61.5%)
Post-CRT N stage				0.006
N0	8 (29.6%)	20 (46.5%)	42 (64.6%)
N+	19 (70.4%)	23 (53.5%)	23 (35.4%)
Post-CRT M stage				0.090
0	25 (92.6%)	42 (97.7%)	65 (100%)
1	2 (7.4%)	1 (2.3%)	0
Post-CRT TNM Stage				0.008
0	0	0	2 (3.1%)
I	2 (7.4%)	4 (9.3%)	19 (29.2%)
II	5 (18.5%)	15 (34.9%)	21 (32.3%)
III	19 (66.7%)	23 (53.5%)	23 (35.4%)
IV	2 (7.4%)	1 (2.3%)	0
Down-staging on MRI after CRT				0.013
No	21 (77.8%)	25 (58.1%)	29 (44.6%)
Yes	6 (22.2%)	18 (41.9%)	36 (55.4%)

Group A: Patients with pre- and post-CRT CEA levels > 5 ng/mL; Group B: Patients with pre- and post-CRT CEA levels > 5 and ≤ 5 ng/mL, respectively; Group C: Patients with pre- and post-CRT CEA levels ≤ 5 ng/mL. ASA: American Society of Anesthesiology; CRT: Chemoradiotherapy; CEA: Carcinoembryonic antigen; NLR: Neutrophil–lymphocyte ratio; PLR: Platelet–lymphocyte ratio; TNM: Tumor Node Metastasis; MRI: Magnetic resonance imaging.