Table 2.
The presence of T-cells, expression of IDO, TDO, PD-L1 and MMRp in NETs
| All NET N (%) | NSP-NET N (%) | SP-NET N (%) | p-value | |
|---|---|---|---|---|
| Tissue samples | 51 (100) | 18 (100) | 33 (100) | |
| PD-L1 expression (22C3 antigen) | ||||
| Negative | 51 (100) | 18 (100) | 33 (100) | NS |
| Positive | 0 (0) | 0 (0) | 0 (0) | |
| PD-L1 expression ( E1L3N antigen) | ||||
| Negative | 51 (100) | 18 (100) | 33 (100) | NS |
| Positive | 0 (0) | 0 (0) | 0 (0) | |
| MMRp | ||||
| Loss of MMRp | 0 (0) | 0 (0) | 0(0) | NS |
| No loss of MMRp | 51 (100) | 18 (100) | 33 (100) | |
| T-cells | ||||
| Absent | 30 (59) | 10 (56) | 20 (61) | NS |
| Present | 15 (29) | 6 (33) | 9 (27) | |
| Not evaluable | 6 (12) | 2 (11) | 4 (12) | |
| IDO expression | ||||
| Negative | 29 (57) | 14 (78) | 15 (45) | 0.039 |
| Positive | 22 (43) | 4 (22) | 18 (55) | |
| TDO expression in tumour cells | ||||
| Negative | 29 (63) | 11 (65) | 18 (62)a | NS |
| Positive | 17 (37) | 6 (35) | 11 (38) | |
| Not evaluable | 5 (10) | 1 (6) | 4 (12) | |
| TDO expression in stroma | ||||
| Negative | 23 (56) | 14 (88) | 9 (36) | 0.001 |
| Positive | 18 (44) | 2 (13) | 16 (64) | |
| Not evaluable | 10 (20) | 2 (11) | 8 (24) | |
IDO indoleamine 2,3-dioxygenase, MMRp mismatch repair proteins, NET neuroendocrine tumour, NSP-NETs non-serotonin-producing neuroendocrine tumour, PD-L1 programmed death-ligand 1, SP-NETs serotonin-producing neuroendocrine tumour, TDO tryptophan 2,3-dioxygenase
aThree tissue samples of SP-NETs with not evaluable stroma were TDO positive in the tumour