<b>Methods:</b> CD163<sup>+</sup> macrophages, CD3<sup>+</sup> T-cells, PD-L1/PD-L2 and HLA class I expression (HCA2, HC10 and β2m) were evaluated using immunohistochemistry in primary tumors (n = 75), local relapses (n = 6) and metastases (n = 19) of 87 LMS patients, as well as in benign leiomyomas (n = 7).
PD-L1 expression was analyzed by immunohistochemistry using two different antibodies in primary tumors and paired metastases from 81 melanoma patients treated at a single institution.
PD-L1 is also expressed on the K7M2 osteosarcoma tumor cell line that establishes metastases in mice, and PD-1 is expressed on tumor-infiltrating CTLs during disease progression.
PD-L1 expression was analyzed using immunohistochemistry (Merck; clone 22C3) in 678 stages I-III NSCLC and 52 paired nodal metastases using tissue microarrays.
PD-L1 expression was significantly associated with poor prognostic factors such as a higher ISUP nucleolar grade (p = 0.01), metastases at diagnosis (p = 0.01), a sarcomatoid component (p = 0.04), overexpression of VEGF (p = 0.006), and cytoplasmic PAR-3 expression (p = 0.01).
PD-L1 expression (clone SP142) was investigated in esophageal adenocarcinomas using tissue microarrays (TMA) from 112 primary resected tumors, preoperative biopsies and full slide sections from a subset of these cases (n = 24), corresponding lymph node (n = 55) and distant metastases (n = 17).
PD-L1 expression was associated with aggressive pathological features of PSCs including N2-involvement (PD-L1 positive in 83.3% of N2-PSCs vs in 16.2% of N0/N1-PSCs, p=0.003) and presence of either local (p=0.038) and distant metastases (p=0.022).
PD-L1 is frequently expressed in intracranial SFT/HPCs, and diffuse or intense PD-L1 expression might be associated with the early occurrence of extracranial metastases.
PD-L1 positivity was observed in 33% and 39% of primary melanomas and matched metastases, respectively, with, however, poor concordance between the primary and the matched metastatic site (κ = 0.283).
A positive correlation between PD-L1 negativity and mucinous and poorly cohesive carcinoma could be shown (p = 0.043), while no association existed for either gender, T-stage, N-stage, grading, surgical resection status, neoadjuvant therapy, distant metastases, lymphovascular or perineural invasion.
All patients receiving a single-agent ICI (cytotoxic T-lymphocyte-associated protein 4 [CTLA-4] or programmed death(ligand)1 [PD(L)-1] inhibitors) for the standard treatment of a locally advanced or metastatic cancer were included in this retrospective multicentric series.
Although there is no difference in infiltrating CD8<sup>+</sup> T cells between UM and CM, a significant decrease in programmed death-1 (PD-1)-positive lymphocytes was observed and lower levels of programmed death ligand-1 (PD-L1) in UM metastases compared with CM metastases.
As platelets help protect tumor cells from immune elimination in the circulatory system, we hypothesized that tumor PD-L1 and circulating platelets might synergistically promote tumor metastasis, and that the prognostic significance of PD-L1 might vary according to platelet count.
By further combining with the checkpoint blockade adjusted by programmed death ligand 1 (PD-L1) antibody, the Fe<sub>3</sub>O<sub>4</sub>-R837 SP-involved PTT cannot only eliminate the primary tumors but also prevent tumor metastasis to lungs/liver.