Table 1 Characteristics by the two cohorts of CRC patients

Preoperative

 Preoperative CEA

3.9 [2.2, 9.0]

3.5 [1.9, 9.5]

0.120

 Preoperative CA19-9

12.6 [7.5, 22.9]

13.0 [6.1, 34.5]

0.054

 Preoperative CA125

12.9 [9.0, 18.7]

11.5 [7.9, 17.4]

0.002

Postoperative

 Postoperative CEA

1.9 [1.2, 2.9]

1.9 [1.2, 2.8]

0.807

 Postoperative CA19-9

9.4 [5.9, 15.9]

7.2 [4.0, 13.5]

 < 0.001

 Postoperative CA125

24.5 [16.2, 39.3]

18.1 [11.0, 31.4]

 < 0.001

Covariate

 Age

58.0 [49.0, 65.0]

57.0 [47.0, 63.0]

0.055

 Male, n (%)

861 (59.3)

259 (58.3)

0.771

Primary site

 < 0.001

  Colon, n (%)

746 (51.3)

341 (76.8)

  Rectum, n (%)

707 (48.7)

103 (23.2)

 Surgical approach

 < 0.001

  Laparoscopic resection, n (%)

551 (37.9)

381 (85.8)

  Open resection, n (%)

902 (62.1)

63 (14.2)

 Tumor differentiation

 < 0.001

  Well, n (%)

8 (0.6)

74 (16.7)

  Moderate, n (%)

908 (62.5)

246 (55.4)

  Poor-undifferentiated, n (%)

454 (31.2)

124 (27.9)

  Unknown, n (%)

83 (5.7)

0 (0.0)

 AJCC 8th ed. Stage

0.195

  I, n (%)

189 (13.0)

71 (16.0)

  II, n (%)

584 (40.2)

163 (36.7)

  III, n (%)

680 (46.8)

210 (47.3)

 Lymph node yield

 < 0.001

  < 12, n (%)

287 (19.8)

36 (8.1)

  ≥ 12, n (%)

1166 (80.2)

408 (91.9)

 Mucinous (colloid) type

98 (6.7)

29 (6.5)

0.961

 Lymphovascular invasion

123 (8.5)

56 (12.6)

0.012

 Perineural invasion

30 (2.1)

83 (18.7)

 < 0.001

 Adjuvant chemotherapy

1252 (86.2)

415 (93.5)

 < 0.001