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).
Positive PD-L1 expression was found in 13% of primary tumours, 25% of relapses and 48% of metastases and correlated with a high T-cell infiltrate (p = 0.002).
We herein characterize PD-L1 expression in breast cancers across the full range of histomorphologies and investigate its intratumoral heterogeneity and fidelity across primaries and metastases.
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).
The clinical success of immunotherapy that inhibits the negative immune regulatory pathway programmed cell death protein 1/PD-1 ligand (PD-1/PD-L1) has initiated a new era in the treatment of metastatic cancer.
We performed PD-L1 immunohistochemistry on 74 cases of high risk HNcSCC with 38 matched metastases and evaluated clinicopathological associations, prognostic significance and heterogeneity in matched metastases.
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.
Significant PDL1 transcript level reductions were seen in patients who developed metastases, as well as those who had local recurrence, compared to patients who remained disease-free.
On 27 paired samples, IC1/2/3 score on TCs was homogeneous distributed with 59.3% in primary tumors and metastases, but with a high discordance rate of 44.4% of PD-L1 positivity on ICs.
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).