Table 1 Clinicopathological factors associated with PD-L1 expression in liver metastasis
| Â | PD-L1 expressiona, N (%) | P value | |
|---|---|---|---|
Negative | Positive | Â | |
Year of diagnosis | 0.36 | ||
  ~ 2009 | 18 (50.0) | 18 (50.0) |  |
 2010 ~  | 15 (39.5) | 23 (60.5) |  |
Age (years, median 56) | 0.85 | ||
  < 56 | 16 (45.7) | 19 (54.3) |  |
  ≥ 56 | 17 (43.6) | 22 (56.4) |  |
Gender | 0.52 | ||
 Male | 21 (42.0) | 29 (58.0) |  |
 Female | 12 (50.0) | 12 (50.0) |  |
Primary tumor site | 0.02* | ||
 Colon | 23 (57.5) | 17 (42.5) |  |
 Rectum | 10 (29.4) | 24 (70.6) |  |
Metastatic time model | 0.95 | ||
 Concurrent | 28 (44.4) | 35 (55.6) |  |
 Metachronous | 5 (45.5) | 6 (54.5) |  |
Resection time model | 0.60 | ||
 Concurrent | 24 (42.9) | 32 (57.1) |  |
 Metachronous | 9 (50.0) | 9 (50.0) |  |
T category (AJCC TNM 8th) | 0.31 | ||
 T1 + T2 | 1 (16.7) | 5 (83.3) |  |
 T3 | 5 (45.5) | 6 (54.5) |  |
 T4 | 27 (47.4) | 30 (52.6) |  |
N category (AJCC TNM 8th) | 0.99 | ||
 N0 | 6 (37.5) | 10 (62.5) |  |
 N1 | 10 (52.6) | 9 (47.4) |  |
 N2 | 11 (40.7) | 16 (59.3) |  |
 Nx | 6 (50.0) | 6 (50.0) |  |
Tumor differentiation | 0.16 | ||
 Poor | 6 (66.7) | 3 (33.3) |  |
 Moderate | 27 (41.5) | 38 (58.5) |  |
Extra-hepatic metastasis | Â | ||
 No | 28 (42.4) | 38 (57.6) |  |
 Yes | 5 (62.5) | 3 (37.5) |  |
CD4 densityb in liver metastatic tumor | 0.05* | ||
 Absent and low | 18 (56.3) | 13 (43.8) |  |
 High | 15 (35.7) | 28 (64.3) |  |
CD8 densityb in liver metastatic tumor |  < 0.001* | ||
 Absent and low | 32 (57.1) | 24 (42.9) |  |
 High | 1 (5.6) | 17 (94.4) |  |