Table 1 Clinical baseline features of SEER and Xijing hospital database

Age at diagnosis, n (%)

 0–9

14 (0.1)

0(0)

0(0)

 10–19

128 (1.0)

31 (0.9)

0(0)

 20–29

265 (2.0)

67 (2.0)

4 (1.2)

 30–39

390 (2.9)

79 (2.4)

5 (1.5)

 40–49

1084 (8.1)

251 (7.5)

35 (10.7)

 50–59

3632 (27.0)

945 (28.2)

104 (31.9)

 60–69

3649 (27.2)

911 (27.1)

92 (28.2)

 70–79

2659 (19.8)

670 (20.0)

65 (19.9)

 80–89

1403 (10.4)

354 (10.5)

21 (6.4)

90–99

204 (1.5)

49 (1.5)

0(0)

Gender, n (%)

 Female

6982 (52.0)

1695 (50.5)

189 (58.0)

 Male

6446 (48.0)

1662 (49.5)

137 (42.0)

Race, n (%)

 White

10,226 (76.2)

2552 (76.0)

0(0)

 Black

1754 (13.1)

466 (13.9)

0(0)

 Asian or Pacific Islander

1354 (10.1)

319 (9.5)

326 (100.0)

 American Indian/Alaska Native

94 (0.7)

20 (0.6)

0(0)

Marital status at diagnosis, n (%)

 Married and separated

7615 (56.7)

1855(55.2)

322 (98.8)

 Divorced

1207 (9.0)

293 (8.7)

2 (0.6)

 Unmarried

2219 (16.5)

559 (16.7)

2 (0.6)

 Other

2387(17.8)

650(19.3)

0(0)

LM, n (%)

 Yes

12,821 (95.5)

3202 (95.4)

318 (97.5)

 No

607 (4.5)

155 (4.6)

8 (2.5)

Primary site, n (%)

 Rectum, NOS

3786 (28.2)

955 (28.4)

228 (69.9)

 Sigmoid colon

2925 (21.8)

777 (23.1)

35 (10.7)

 Ascending colon

1646 (12.3)

413 (12.3)

24 (7.4)

 Cecum

1586 (11.8)

393 (11.7)

6 (1.8)

 Appendix

868 (6.5)

216 (6.4)

0(0)

 Rectosigmoid junction

846 (6.3)

215 (6.4)

7 (2.1)

 Transverse colon

723 (5.4)

166 (4.9)

9 (2.8)

 Descending colon

481 (3.6)

106 (3.2)

1 (0.3)

 Hepatic flexure of colon

303 (2.3)

70 (2.1)

7 (2.1)

 Splenic flexure of colon

172 (1.3)

31 (0.9)

3 (0.9)

 Colon, NOS

50 (0.4)

9 (0.3)

4 (1.2)

 Overlapping lesion of colon

42 (0.3)

6 (0.2)

2(0.6)

 Tumor size, mm, mean (SD)

19.16 (25.1)

18.82 (22.3)

24.6 (14.0)

Tumor grade, n (%)

 Well differentiated; Grade I

4171 (31.1)

1015 (30.2)

69 (21.2)

 Moderately differentiated; Grade II

8306 (61.9)

2114 (63.0)

240 (73.6)

 Poorly differentiated; Grade III

827 (6.2)

191 (5.7)

15 (4.6)

 Undifferentiated; anaplastic; Grade IV

124 (0.9)

37 (1.1)

2 (0.6)

Tumor type, n (%)

 Adenocarcinoma, NOS

4368 (32.5)

1099 (32.7)

91 (27.9)

 Adenocarcinoma in tubulovillous adenoma

2969 (22.1)

743 (22.1)

76 (23.3)

 Adenocarcinoma in adenomatous polyp

2827 (21.1)

708 (21.1)

125 (38.3)

 Carcinoid tumor, NOS

1837 (13.7)

454 (13.5)

0(0)

 Adenocarcinoma in villous adenoma

483 (3.6)

126 (3.8)

9 (2.8)

 Neuroendocrine carcinoma, NOS

409 (3.0)

93 (2.8)

0(0)

 Mucinous adenocarcinoma

238 (1.8)

61 (1.8)

7 (2.1)

 Squamous cell carcinoma, NOS

52 (0.4)

8 (0.2)

0(0)

 Atypical carcinoid tumor

38 (0.3)

11 (0.3)

0(0)

 Signet ring cell carcinoma

28 (0.2)

6 (0.2)

0(0)

 Mucin-producing adenocarcinoma

26 (0.2)

6 (0.2)

0(0)

 Tubular adenocarcinoma

22 (0.2)

8 (0.2)

18 (5.5)

 Gastrointestinal stromal sarcoma

17 (0.1)

0(0)

0(0)

 Carcinoma, NOS

14 (0.1)

5 (0.1)

0(0)

 Villous adenocarcinoma

10 (0.1)

2 (0.1)

0(0)

 Other

90 (0.7)

27 (0.8)

0(0)

N, n (%)

 N0

12,142 (90.4)

3031 (90.3)

295 (90.5)

 N1

1150 (8.6)

296 (8.82)

30 (9.2)

 N2

136 (1.0)

30 (0.9)

1 (0.3)

CEA, n (%)

 Positive

1223 (9.1)

300 (8.9)

110 (33.7)

 Borderline

25 (0.2)

6 (0.2)

0(0)

 Negative

3974 (29.6)

993 (29.6)

200 (61.3)

 Unknown

8206 (61.1)

2058 (61.3)

16 (4.9)

Tumor deposits, n (%)

 No tumor deposits

8777 (65.4)

2213 (65.9)

325 (99.7)

 Tumor Deposits identified

95 (0.7)

27 (0.8)

1 (0.3)

 Unknown

4556 (33.9)

1117 (33.3)

0(0)

Perineural invasion, n (%)

 Yes

9104 (67.8)

2246 (66.9)

169 (51.8)

 No

105 (0.8)

48 (1.4)

157 (48.2)

Unknown

4219 (31.4)

1063 (31.7)

0(0)