Table 1 Patient characteristics

Age (years)

 Mean (SD)

58.72 (12.71)

58.11 (12.87)

59.17 (12.59)

0.408

 Median (IQR)

60.00 (21.00–87.00)

60.00 (21.00–85.00)

61.00 (22.00–87.00)

BMI (kg/m²)

 Mean (SD)

22.36 (3.25)

22.70 (3.24)

22.12 (3.23)

0.077

 Median (IQR)

21.89 (13.89–34.29)

22.04 (15.24–31.60)

21.78 (13.89–34.29)

Recurrence group

0.005

 Local recurrence

31 (7.64%)

19 (11.11%)

12 (5.11%)

 Distant metastasis

315 (77.59%)

136 (79.53%)

179 (76.17%)

 Simultaneous recurrence

60 (14.78%)

16 (9.36%)

44 (18.72%)

Recurrence time

0.058

 Early recurrence

252 (62.07%)

97 (56.73%)

155 (65.96%)

 Late recurrence

154 (37.93%)

74 (43.27%)

80 (34.04%)

Recurrence site

0.013

 Liver

98 (24.14%)

47 (27.49%)

51 (21.70%)

 Lung

127 (31.28%)

52 (30.41%)

75 (31.91%)

 Peritoneum

32 (7.88%)

7 (4.09%)

25 (10.64%)

 Other individual organ

69 (17.00%)

31 (18.13%)

38 (16.17%)

 Two or more organs or sites

49 (12.07%)

15 (8.77%)

34 (14.47%)

 Local recurrence

31 (7.64%)

19 (11.11%)

12 (5.11%)

Liver

0.179

 No

308 (75.86%)

124 (72.51%)

184 (78.30%)

 Yes

98 (24.14%)

47 (27.49%)

51 (21.70%)

Lung

0.747

 No

279 (68.72%)

119 (69.59%)

160 (68.09%)

 Yes

127 (31.28%)

52 (30.41%)

75 (31.91%)

Peritoneum

0.016

 No

374 (92.12%)

164 (95.91%)

210 (89.36%)

 Yes

32 (7.88%)

7 (4.09%)

25 (10.64%)

Other individual organ

0.604

 No

337 (83.00%)

140 (81.87%)

197 (83.83%)

 Yes

69 (17.00%)

31 (18.13%)

38 (16.17%)

Two or more organs or sites

0.082

 No

357 (87.93%)

156 (91.23%)

201 (85.53%)

 Yes

49 (12.07%)

15 (8.77%)

34 (14.47%)

Local recurrence

0.024

 No

375 (92.36%)

152 (88.89%)

223 (94.89%)

 Yes

31 (7.64%)

19 (11.11%)

12 (5.11%)

Sex, no. (%) of patients

0.738

 Male

220 (54.19%)

91 (53.22%)

129 (54.89%)

 Female

186 (45.81%)

80 (46.78%)

106 (45.11%)

Surgical approach

0.056

 OR

291 (71.67%)

114 (66.67%)

177 (75.32%)

 LR

115 (28.33%)

57 (33.33%)

58 (24.68%)

Primary site

0.102

 Right colon

105 (25.86%)

36 (21.05%)

69 (29.36%)

 Left colon

85 (20.94%)

42 (24.56%)

43 (18.30%)

 Rectum

216 (53.20%)

93 (54.39%)

123 (52.34%)

Tumor differentiation, no. (%) of patients

0.340

 Unknown

39 (9.61%)

17 (9.94%)

22 (9.36%)

 Well

15 (3.69%)

6 (3.51%)

9 (3.83%)

 Moderate

199 (49.01%)

92 (53.80%)

107 (45.53%)

 Poor-undifferentiated

153 (37.68%)

56 (32.75%)

97 (41.28%)

Mucinous type

0.260

 No

386 (95.07%)

165 (96.49%)

221 (94.04%)

 Yes

20 (4.93%)

6 (3.51%)

14 (5.96%)

T stage, no. (%) of patients

0.068

 T0

12 (2.96%)

8 (4.68%)

4 (1.70%)

 T1

34 (8.37%)

18 (10.53%)

16 (6.81%)

 T3

336 (82.76%)

132 (77.19%)

204 (86.81%)

 T4

24 (5.91%)

13 (7.60%)

11 (4.68%)

N stage, no. (%) of patients

 < 0.001

 N0

158 (38.92%)

87 (50.88%)

71 (30.21%)

 N1

149 (36.70%)

57 (33.33%)

92 (39.15%)

 N2

99 (24.38%)

27 (15.79%)

72 (30.64%)

AJCC 8th ed. stage

 < 0.001

 I

39 (9.61%)

24 (14.04%)

15 (6.38%)

 II

119 (29.31%)

63 (36.84%)

56 (23.83%)

 III

248 (61.08%)

84 (49.12%)

164 (69.79%)

Lymph node yield, n (%)

0.267

  < 12

98 (24.14%)

46 (26.90%)

52 (22.13%)

  ≥ 12

308 (75.86%)

125 (73.10%)

183 (77.87%)

LVI

0.022

 Unknown

54 (13.30%)

28 (16.37%)

26 (11.06%)

 Yes

56 (13.79%)

15 (8.77%)

41 (17.45%)

 No

296 (72.91%)

128 (74.85%)

168 (71.49%)

PNI

0.270

 Unknown

81 (19.95%)

34 (19.88%)

47 (20.00%)

 Yes

23 (5.67%)

6 (3.51%)

17 (7.23%)

 No

302 (74.38%)

131 (76.61%)

171 (72.77%)

Tumor deposit, no. (%) of patients

0.191

 No

340 (83.74%)

148 (86.55%)

192 (81.70%)

 Yes

66 (16.26%)

23 (13.45%)

43 (18.30%)

Adjuvant chemotherapy, no. (%) of patients

0.635

 No

109 (26.85%)

48 (28.07%)

61 (25.96%)

 Yes

297 (73.15%)

123 (71.93%)

174 (74.04%)

Chemotherapy regimen

0.524

 5-FU/capecitabine

25 (8.42%)

13 (10.57%)

12 (6.90%)

 CAPOX/XELOX

90 (30.30%)

34 (27.64%)

56 (32.18%)

 FOLFOX

164 (55.22%)

70 (56.91%)

94 (54.02%)

 Other

18 (6.06%)

6 (4.88%)

12 (6.90%)

Chemotherapy cycle

0.748

  < 6

153 (51.52%)

62 (50.41%)

91 (52.30%)

  ≥ 6

144 (48.48%)

61 (49.59%)

83 (47.70%)

Adjuvant radiotherapy

0.197

 No

385 (94.83%)

165 (96.49%)

220 (93.62%)

 Yes

21 (5.17%)

6 (3.51%)

15 (6.38%)

Palliative chemotherapy

0.581

 No

32 (7.88%)

12 (7.02%)

20 (8.51%)

 Yes

374 (92.12%)

159 (92.98%)

215 (91.49%)

Preoperative CEA, ng/mL

 Mean (SD)

31.22 (254.29)

13.14 (23.55)

44.34 (333.10)

0.225

 Median (IQR)

5.33 (0.20–4688.00)

4.13 (0.49–150.50)

5.87 (0.20–4688.00)

Preoperative CA19-9, ng/ml Mean

 (SD)

37.82 (90.08)

25.42 (36.39)

46.80 (113.46)

0.020

 Median (IQR)

15.53 (0.59–1405.00)

14.80 (0.60–253.10)

16.78 (0.59–1405.00)

Postoperative CEA, ng/mL Mean

 (SD)

34.36 (233.80)

5.55 (16.92)

55.41 (305.78)

0.042

 Median (IQR)

2.38 (0.20–2965.00)

2.00 (0.20–174.60)

2.72 (0.20–2965.00)