Supplementary Table 1. Site of Tumor Recurrence

Supplementary Table 1. Site of Tumor Recurrence

Training set (N=965) / Validation set (N=268) / pvalue
No recurrence / 835 (86.5%) / 231 (86.2%) / 0.920
Local-only / 7 (0.7%) / 2 (0.7%) / 1.000
Intra-abdominal / 74 (7.7%) / 21 (7.8%) / 0.898
Extra-abdominal / 57 (5.9%) / 17 (6.3%) / 0.772
Distant / 123 (12.7%) / 35 (13.1%) / 0.918

Supplementary Table 2. Patient Characteristics, Treatment Characteristics, and Outcomes According to Preoperative CEA

Training set (N=965) / Validation set (N=268)
CEA ≥3 ng/mL (N=472) / CEA < 3 ng/mL (N=493) / p value / CEA ≥3 ng/mL (N=141) / CEA < 3 ng/mL (N=127) / pvalue
Age / 0.005 / 0.905
Median / 61 / 59 / 60 / 60
Range / 28-81 / 14-84 / 27-80 / 34-79
Sex / 0.366 / 0.714
Male / 247 (47.5%) / 273 (52.5%) / 67 (51.1%) / 64 (48.9%)
Female / 225 (50.6%) / 220 (49.4%) / 74 (54.0%) / 63 (46.0%)
Smoking history / 0.361 / 0.572
Never smoker / 358 (47.7%) / 392 (52.3%) / 104 (51.0%) / 100 (49.0%)
Former smoker / 68 (51.9%) / 63 (48.1%) / 24 (60.0%) / 16 (40.0%)
Current smoker / 46 (54.8%) / 38 (45.2%) / 13 (54.2%) / 11 (45.8%)
Location / 0.755 / 0.862
Ascending colon / 127 (46.5%) / 146 (53.5%) / 37 (52.1%) / 34 (47.9%)
Transverse colon / 32 (50.8%) / 31 (49.2%) / 11 (61.1%) / 7 (38.9%)
Descending colon / 24 (46.2%) / 28 (53.8%) / 6 (46.2%) / 7 (53.8%)
Sigmoid colon / 289 (50.1%) / 288 (49.9%) / 87 (52.4%) / 79 (47.6%)
Differentiation / 0.313 / 0.626
Well / 29 (40.3%) / 43 (59.7%) / 9 (50.0%) / 9 (50.0%)
Moderate / 400 (49.6%) / 406 (50.4%) / 122 (53.7%) / 105 (46.3%)
Poor / 43 (49.4%) / 44 (50.6%) / 10 (43.5%) / 13 (56.5%)
Stage / <0.001 / <0.001
IIIA / 21 (19.3%) / 88 (80.7%) / 6 (18.2%) / 27 (81.8%)
IIIB / 305 (47.5%) / 337 (52.5%) / 99 (56.9%) / 75 (43.1%)
IIIC / 146 (68.2%) / 68 (31.8%) / 36 (59.0%) / 25 (41.0%)
T stage / <0.001 / <0.001
T1 / 10 (25.6%) / 29 (74.4%) / 2 (14.3%) / 12 (85.7%)
T2 / 11 (15.7%) / 59 (84.3%) / 3 (14.3%) / 18 (85.7%)
T3 / 365 (52.0%) / 337 (48.0%) / 108 (56.0%) / 85 (44.0%)
T4 / 86 (55.8%) / 68 (44.2%) / 28 (70.0%) / 12 (30.0%)
N stage / <0.001 / <0.001
N1 / 274 (44.1%) / 348 (55.9%) / 83 (46.6%) / 95 (53.4%)
N2 / 198 (57.7%) / 145 (42.3%) / 58 (64.4%) / 32 (35.6%)
No. of retrieved LNs / 0.207 / 0.496
≥12 / 429 (49.7%) / 435 (50.3%) / 128 (51.8%) / 119 (48.2%)
<12 / 43 (42.6%) / 58 (57.4%) / 13 (61.9%) / 8 (38.1%)
LVI or PNI / 0.399 / 0.214
Absence / 260 (47.7%) / 285 (52.3%) / 79 (49.4%) / 81 (50.6%)
Presence / 212 (50.5%) / 208 (49.5%) / 62 (57.4%) / 46 (42.6%)
Adjuvant chemotherapy / 0.091 / 0.476
FOLFOX / 440 (48.2%) / 472 (51.8%) / 129 (51.8%) / 120 (48.2%)
XELOX / 32 (60.4%) / 21 (39.6%) / 12 (63.2%) / 7 (36.8%)
Relative dose intensity / 0.552 / 0.741
Mean / 88.1% / 88.3% / 91.4% / 90.7%
95% CI / 86.1-90.1% / 86.5-90.1% / 88.4-94.4% / 87.4-93.9%
Recurrence pattern
Bone / 3 (0.6%) / 1 (0.2%) / 0.364 / 2 (1.4%) / 1 (0.8%) / 1.000
Distant LNs / 11 (2.3%) / 6 (1.2%) / 0.225 / 3 (2.1%) / 2 (1.6%) / 1.000
Liver / 32 (6.8%) / 6 (1.2%) / <0.001 / 10 (7.1%) / 3 (2.4%) / 0.090
Local-only / 5 (1.1%) / 2 (0.4%) / 0.277 / 2 (1.4%) / 0 (0.0%) / 0.499
Lung / 33 (7.0%) / 10 (2.0%) / <0.001 / 10 (7.1%) / 2 (1.6%) / 0.037
Ovary / 9 (1.9%) / 4 (0.8%) / 0.169 / 3 (2.1%) / 0 (0.0%) / 0.249
Peritoneum / 22 (4.7%) / 3 (0.6%) / <0.001 / 4 (2.8%) / 2 (1.6%) / 0.687
Ureter / 1 (0.2%) / 1 (0.2%) / 1.000 / 0 (0.0%)1 / 7 (0.8%) / 0.474

5-FU 5-fluorouracil,CEAcarcinoembryonic antigen,CIconfidence interval,LNs Lymph nodes,LVIlymphovascular invasion,PNIperineural invasion,FOLFOX 5-fluorouracil/leucovorin/oxaliplatin,XELOXcapecitabine/oxaliplatin

Supplementary Table 3.Correlation of Serum CEA at Baseline and Recurrence

CEA at recurrence
Training set (N=130) / Validation set (N=37)
≥3ng/mL (N=99) / < 3ng/mL (N=31) / p value / ≥3ng/mL (N=28) / < 3ng/mL (N=9) / pvalue
Preoperative serum CEA / 0.001 / 0.045
≥3 ng/mL / 88 (84.6%) / 16 (42.3%) / 25 (83.3%) / 5 (42.9%)
<3 ng/mL / 11 (15.4%) / 15 (57.7%) / 3 (16.7%) / 4 (57.1%)

CEAcarcinoembryonic antigen