Fig. 1Immunohistochemical staining of CD8 (A-D) and forkhead box P3 (E-H) of non-neoplastic colon (A, E), low-grade tubular adenoma (B, F), high-grade tubular adenoma (C, G), and invasive colorectal cancer (D, H). The degree of CD8+ T cell infiltration is progressively decreased, while that of regulatory T cells infiltration gradually increased during colorectal cancer development.
Fig. 2Analysis of the number of both T cell types (A) and CD8+ T cells/regulatory T cells (Tregs) ratio (B) in the center of lesions during colorectal cancer (CRC) development. The number of CD8+ T cells decreases progressively, while the number of Tregs gradually increases during CRC development (p<.001). The number of CD8+ T cells and Tregs in neoplastic diseases is significantly different from that of non-neoplastic diseases (p<.001) and that of both T cell types in low-grade tubular adenoma is also significantly different from that in high-grade tubular adenoma and CRC (p<.001 for Tregs, p=.002 for CD8+ T cells). The ratio progressively decreases during CRC development (p<.001). It is significantly higher in non-neoplastic conditions than in neoplastic diseases and that of low-grade tubular adenoma is also significantly higher than that of other neoplastic diseases (p<.001).
Fig. 3Analysis of the number of both T cells (A) and CD8+ T cells/regulatory T cells (Tregs) ratio (B) in the tumor boundary during colorectal cancer (CRC) development. The number of Tregs is significantly higher in high-grade tubular adenoma and invasive CRC than in low-grade tubular adenoma (p<.001). In contrast, there is no significant difference in the number of CD8+ T cells between groups. The ratio is significantly lower in high-grade tubular adenoma and invasive CRC than in low-grade tubular adenoma (p<.001).
Fig. 4Analysis of the distribution of the number of both T cells (A) and CD8+ T cells/regulatory T cells (Tregs) ratio (B) among tumor compartments of tubular adenomas and invasive colorectal cancer (CRC). Low-grade tubular adenoma shows a higher number of CD8+ T cells in the boundary than in the tumor center (p=.01), and high-grade tubular adenoma reveals a higher number of both T cells in the boundary than in the tumor center (p=.009 for Tregs, p<.001 for CD8+ T cells). In the case of invasive CRC, the number of CD8+ T cells is higher in both the invasive front and boundary than in other areas and lowest in the tumor center (p<.001). The number of Tregs is lowest in adjacent non-neoplastic mucosa, while other findings are similar to those for CD8+ T cell distribution (p<.001). The ratio in the tumor center is the lowest in both tubular adenomas and invasive CRC (p=.017 for low-grade tubular adenoma, p=.003 for high-grade tubular adenoma, p<.001 for invasive CRC).
Fig. 5Immunohistochemical staining of cyclooxygenase-2 (COX-2) in low-grade tubular adenoma (A), high-grade tubular adenoma (B) and invasive colorectal cancer (CRC) (C), and a relationship between COX-2 expression and the number of regulatory T cells (Tregs) in tumors and all subjects (D). COX-2 expression is mainly localized in the subepithelial stromal cells in the periluminal region of tubular adenomas and CRC (arrows). The number of Tregs is significantly higher in tissues with COX-2 expression than in tissues with no COX-2 expression (p<.001). This finding is also found when applied to only neoplastic diseases (p=.005).
Table 1.Characteristics of patients
Variable |
No. of cases |
Age distribution (yr) |
Gender (male:female) |
Non-neoplastic colon |
17 |
43-76 |
11:6 |
Hyperplasitc polyp |
15 |
22-67 |
9:6 |
Low-grade tubular adenoma |
22 |
35-78 |
12:10 |
High-grade tubular adenoma |
27 |
42-82 |
20:7 |
Intramucosal CRC |
10 |
52-78 |
5:5 |
Invasive CRC |
32 |
57-87 |
20:12 |
Table 2.The number of CD8+ T cells and Tregs, and the CD8+ T cells/Tregs ratio among tumor compartment according to clinicopathological parameters in invasive CRC
Variable |
Group |
Location of CD8+ T cells
|
Location of Tregs
|
Location of CD8+ T cells/Tregs
|
Tumor center |
Invasive front |
Boundary |
Adjacent tissue |
Tumor center |
Invasive front |
Boundary |
Adjacent tissue |
Tumor center |
Invasive front |
Boundary |
Adjacent tissue |
Gender |
Male |
8.0 ± 6.6 |
28.1 ± 9.9 |
31.6 ± 9.0 |
23.1 ± 5.0 |
32.5 ± 12.8 |
54.2 ± 25.3 |
49.9 ± 19.8 |
13.3 ± 6.2 |
0.25 ± 0.19 |
0.57 ± 0.24 |
0.78 ± 0.52 |
2.27 ± 1.38 |
Female |
12.4 ± 9.2 |
53.4 ± 25.9*
|
34.4 ± 17.2 |
25.3 ± 17.4 |
31.0 ± 13.8 |
54.3 ± 26.4 |
44.1 ± 12.6 |
9.6 ± 3.9 |
0.41 ± 0.19*
|
1.10 ± 0.57*
|
0.78 ± 0.38 |
3.03 ± 2.12 |
Differentiation |
Well |
10.3 ± 5.6 |
60.4 ± 30.3*
|
34.1 ± 13.9 |
32.0 ± 22.7 |
29.0 ± 6.6 |
72.5 ± 35.9 |
58.1 ± 25.9 |
15.4 ± 5.0 |
0.35 ± 0.18 |
1.10 ± 0.81 |
0.72 ± 0.42 |
2.57 ± 2.65 |
Moderate to poor |
9.5 ± 8.3 |
33.3 ± 16.7 |
32.5 ± 12.8 |
22.2 ± 6.8 |
32.5 ± 13.8 |
50.9 ± 22.1 |
45.2 ± 14.4 |
11.1 ± 5.6 |
0.30 ± 0.21 |
0.71 ± 0.36 |
0.79 ± 0.48 |
2.56 ± 1.53 |
Depth |
T2 |
9.5 ± 6.1 |
63.7 ± 31.8*
|
31.0 ± 19.9 |
21.2 ± 4.9 |
34.5 ± 14.8 |
81.2 ± 35.4*
|
52.0 ± 21.6 |
13.9 ± 5.3 |
0.32 ± 0.21 |
0.98 ± 0.79 |
0.70 ± 0.48 |
1.67 ± 0.57 |
T3 |
9.7 ± 8.2 |
32.7 ± 15.2 |
33.2 ± 11.2 |
24.6 ± 12.3 |
31.5 ± 12.9 |
49.3 ± 20.1 |
46.7 ± 16.6 |
11.4 ± 5.7 |
0.31 ± 0.21 |
0.73 ± 0.39 |
0.79 ± 0.47 |
2.26 ± 1.82 |
Location |
Proximal |
8.6 ± 7.8 |
34.1 ± 15.1 |
35.1 ± 9.9 |
29.1 ± 15.3*
|
33.8 ± 16.3 |
55.3 ± 20.7 |
56.2 ± 114.8 |
14.5 ± 5.5 |
0.25 ± 0.16 |
0.68 ± 0.34 |
0.68 ± 0.31 |
2.44 ± 1.87 |
Distal |
10.4 ± 8.0 |
39.9 ± 24.7 |
31.4 ± 14.3 |
20.7 ± 6.5 |
30.7 ± 10.4 |
53.5 ± 28.6 |
42.2 ± 17.0 |
10.1 ± 5.2 |
0.35 ± 0.22 |
0.84 ± 0.53 |
0.83 ± 0.54 |
2.65 ± 1.66 |
Node metastasis |
Absence |
11.2 ± 8.3 |
37.6 ± 22.0 |
32.6 ± 14.9 |
24.9 ± 13.6 |
30.2 ± 11.5 |
54.9 ± 26.6 |
49.4 ± 17.7 |
11.7 ± 5.2 |
0.37 ± 0.21*
|
0.81 ± 0.56 |
0.68 ± 0.32 |
2.60 ± 1.80 |
Presence |
6.7 ± 6.1 |
37.5 ± 20.9 |
33.1 ± 7.7 |
22.3 ± 5.5 |
35.3 ± 15.4 |
53.0 ± 23.8 |
44.3 ± 17.1 |
12.1 ± 6.6 |
0.20 ± 0.14 |
0.71 ± 0.21 |
0.95 ± 0.64 |
2.50 ± 1.65 |
Tumor bud |
< 10 |
13.5 ± 10.1 |
50.1 ± 27.1*
|
37.0 ± 13.1 |
27.9 ± 15.1 |
37.3 ± 11.2 |
62.9 ± 32.0 |
44.8 ± 20.0 |
12.1 ± 5.1 |
0.37 ± 0.22 |
0.90 ± 0.54 |
0.97 ± 0.60 |
2.90 ± 2.04 |
≥ 10 |
7.6 ± 5.7 |
31.0 ± 14.4 |
29.8 ± 12.1 |
21.4 ± 7.7 |
29.2 ± 13.2 |
49.7 ± 20.4 |
49.5 ± 15.8 |
11.7 ± 6.1 |
0.28 ± 0.20 |
0.70 ± 0.41 |
0.65 ± 0.31 |
2.35 ± 1.50 |