Table 3 Logistic regression analysis for factors associated with an obvious discordance of PD-L1 expression between primary tumors and liver metastatic tumors

Year of diagnosis

  ~ 2009

31 (86.1)

5 (13.9)

1

Reference

 2010 ~ 

29 (76.3)

9 (23.7)

1.92

0.58–6.42

Age (years, median 56)

  < 56

27 (77.1)

8 (22.9)

1

Reference

  ≥ 56

33 (84.6)

6 (15.4)

0.61

0.19–1.99

Gender

 Male

38 (76.0)

12 (24.0)

1

Reference

 Female

22 (91.7)

2 (8.3)

0.29

0.06–1.41

Primary tumor site

 Colon

34 (85.0)

6 (15.0)

1

Reference

 Rectum

26 (76.5)

8 (23.5)

1.74

0.54–5.65

Metastatic time model

 Concurrent

50 (79.4)

13 (20.6)

1

Reference

 Metachronous

10 (90.0)

1 (9.1)

0.39

0.05–3.28

Resection time model

 Concurrent

44 (78.6)

12 (21.4)

1

Reference

 Metachronous

16 (88.9)

2 (11.1)

0.46

0.09–2.28

T category (AJCC TNM 8^th)

 T1 + T2

4 (66.7)

2 (33.3)

1

Reference

 T3

11 (100.0)

0 (0.0)

 < 0.001

 < 0.001-NA

 T4

45 (78.9)

14 (18.9)

0.53

0.09–3.27

N category (AJCC TNM 8^th)

 N0

10 (62.5)

6 (37.5)

1

Reference

 N1

17 (89.5)

2 (10.5)

0.20

0.03–1.16

 N2

22 (81.5)

5 (18.5)

0.38

0.09–1.54

 Nx

11 (91.7)

1 (8.3)

0.15

0.02–1.49

Tumor differentiation

 Poor

5 (55.6)

4 (44.4)

1

Reference

1

Reference

 Moderate

55 (84.6)

10 (15.4)

0.23

0.05–1.00

0.18

0.03–0.99

Extra-hepatic metastasis

 No

53 (80.3)

13 (19.7)

1

Reference

 Yes

7 (87.5)

1 (12.5)

0.58

0.07–5.16

Pre-operative chemo/radiotherapy for primary tumor

 No

48 (78.7)

13 (21.3)

1

Reference

 Yes

12 (92.3)

1 (7.7)

0.31

0.04–2.59

Discordance of CD4 density between primary and metastatic tumor

 No

40 (81.6)

9 (18.4)

1

Reference

 Yes

20 (80.0)

5 (20.0)

1.11

0.32–3.76

Discordance of CD8 density between primary and metastatic tumor

 No

41 (93.2)

3 (6.8)

1

Reference

1

Reference

 Yes

19 (63.3)

11 (36.7)

7.91

1.98–31.69

8.95

2.06–39.00