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The success of immunotherapy using immune checkpoint blockade in solid tumors and in relapsed/refractory classical Hodgkin lymphoma and chronic lymphocytic leukemia holds promise for targeted therapy in hematologic malignancies. Because efficacy of immunomodulatory therapy is correlated with numbers of cells that express programmed death (PD-1) ligands, we evaluated the expression of PD-L1 and PD-L2 proteins using immunohistochemistry in more than 702 diagnostic lymphoma biopsies. In classical Hodgkin lymphoma, PD-L1 and PD-L2 were expressed in 82% and 41% of cases, respectively, and PD-L1 but not PD-L2 expression correlated with Epstein-Barr virus in tumor cells. PD-L1 staining was detected in 80% of anaplastic large cell lymphoma, angioimmunoblastic T-cell lymphoma, and follicular dendritic cell sarcoma; 75% of nodular lymphocyte-predominant Hodgkin lymphoma; 53% of primary mediastinal large B-cell lymphoma; 39% of extranodal NK/T cell lymphoma; 26% of peripheral T-cell lymphoma; 10% of diffuse large B-cell lymphoma; and very rare examples of mantle, marginal zone, and small lymphocytic lymphomas. PD-L2 staining was present in 78% of primary mediastinal large B-cell lymphoma but in fewer cases in all other categories including 40% of follicular dendritic cell sarcoma and 7% of anaplastic large cell lymphoma. Our results confirm and extend prior studies of PD-L1 and provide new data of PD-L2 expression in lymphomas. The differential expression patterns in some tumor types and the expression of PD-L2 in the absence of PD-L1 raise the possibility of targeted therapy for additional subsets of patients with lymphoma., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Programmed death ligand 1 (PD-L1) is a key protein upregulated by tumor cells to suppress immune responses. Tumor-associated macrophages (TAMs) play a major role in this immunosuppression, but the relationship between PD-L1 expression and TAMs remains unclear in gastric adenocarcinoma (GAC). We simultaneously examined expression of PD-L1 and TAMs in GAC., Methods: We performed immunohistochemical staining for PD-L1, CD68 (pan-macrophage), and CD163 (M2-like macrophage) in 217 GAC samples using a tissue microarray. Expression of PD-L1 and CD68- and CD163-positive cells was evaluated using the Cytoplasmic V2.0 algorithm in Aperio ImageScope software, and logistic regression analysis was used to compare expression patterns between groups., Results: Thirty-one samples (14%) were positive for PD-L1 expression. The mean (± standard error) rates of infiltration were 6.83 ± 0.38% for CD68-positive cells and 6.16 ± 0.29% for CD163-positive cells. The mean rate of CD163-positive cell infiltration was significantly higher in diffuse GAC than in intestinal GAC (diffuse n = 111, 6.91%; intestinal n = 91, 5.26%; p = 0.006), but the mean rate of CD68-positive cell infiltration was similar between these types (p = 0.38). The mean infiltration rates of CD68- and CD163-positive cells in PD-L1-positive GAC were significantly higher than in PD-L1-negative GAC (CD68 p = 0.0002; CD163 p < 0.0001). In multivariate logistic regression analyses, CD163-positive cell infiltration was associated with PD-L1 expression (odds ratio 1.13; 95% confidence interval 1.02-1.25; p = 0.021)., Conclusion: M2-like macrophage infiltration is highly associated with PD-L1 expression in GAC cells, suggesting that macrophage infiltration can serve as a potential therapeutic target.

Purpose The KEYNOTE-028 trial ( ClinicalTrials.gov identifier: NCT02054806) was designed to assess the safety and efficacy of pembrolizumab in 20 programmed death ligand 1-positive, advanced solid tumor cohorts. Here, we present the results from the cohort of patients with advanced cervical cancer. Methods Patients were treated with pembrolizumab 10 mg/kg every 2 weeks for up to 24 months. Response was assessed every 8 weeks for the first 6 months and every 12 weeks thereafter. The primary end point was overall response rate per Response Evaluation Criteria in Solid Tumors, version 1.1, by investigator review. Safety was a secondary end point. Results Twenty-four patients were enrolled in the cervical cancer cohort. The median age was 42 years (range, 26 to 62 years), 22 patients (92%) had received prior radiation therapy, and 15 patients (63%) had received two or more lines of therapy, including bevacizumab (10 of 24 patients), for advanced disease. At the data cutoff, median follow-up duration was 11.0 months (range, 1.3 to 32.2 months). Overall response rate was 17% (95% CI, 5% to 37%); four patients (17%) achieved a confirmed partial response, and three patients (13%) had stable disease. Median duration of response for the four patients who achieved a partial response was 5.4 months (4.1 to 7.5 months). Treatment related adverse events (AEs) were experienced by 18 patients (75%); only rash (n = 5; 21%) and pyrexia (n = 4; 17%) and occurred in ≥ 10% of patients. Five patients experienced grade 3 treatment-related AEs. No grade 4 treatment-related AEs or deaths were observed. Conclusion In patients with programmed death ligand 1-positive advanced cervical cancer, pembrolizumab demonstrated antitumor activity and exhibited a safety profile consistent with that seen in other tumor types.

Purpose To establish the safety profile and antitumor activity of the anti-programmed death 1 receptor monoclonal antibody, pembrolizumab, in patients with recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) that expressed programmed death-ligand 1 (PD-L1). Patients and Methods KEYNOTE-028 (NCT02054806) is a nonrandomized, multicohort, phase Ib trial of pembrolizumab in patients with PD-L1-positive advanced solid tumors. Key eligibility criteria for the NPC cohort included unresectable or metastatic disease, failure on prior standard therapy, and PD-L1 expression in 1% or more of tumor cells or tumor-infiltrating lymphocytes. Patients received pembrolizumab 10 mg/kg every 2 weeks up to 2 years or until disease progression or unacceptable toxicity. Primary end point was objective response rate (ORR) per investigator review. Tumor response was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1) every 8 weeks for the first 6 months and every 12 weeks thereafter. Results Twenty-seven patients received pembrolizumab. Median age was 52.0 years (range, 18 to 68 years); 92.6% received prior therapies for RM-NPC; 70.4% had received three or more therapies. Partial response and stable disease were observed in seven and 14 patients, respectively, for an ORR of 25.9% (95% CI, 11.1 to 46.3) over a median follow-up of 20 months. ORR by central review was similar (26.3%). Drug-related adverse events that occurred in 15% or more of patients included rash (25.9%), pruritus (25.9%), pain (22.2%), hypothyroidism (18.5%), and fatigue (18.5%). Grade ≥ 3 drug-related adverse events occurred in eight patients (29.6%), and there was one drug-related death (sepsis). As of the data cutoff (June 20, 2016), two patients remained on pembrolizumab treatment. Conclusion Pembrolizumab demonstrated antitumor activity and a manageable safety profile in patients with RM-NPC.

Background: Globo H is a tumor-associated carbohydrate antigen exclusively expressed in cancer cells rather than normal tissue. Globo H has been found on many cancers of epithelial origins, and become an attractive target for cancer vaccine., Objectives: We aimed to study the expression of Globo H in non-small cell lung cancer (NSCLC) patients, and correlated its expression with common driver mutations, clinical outcomes, and status of immune checkpoint, programmed death-ligand 1 (PD-L1)., Methods: The study enrolled 228 patients with surgically resected stage I NSCLC, including 139 patients with adenocarcinoma (ADC) and 89 patients with squamous cell carcinoma (SqCC). Using immunohistochemistry, tumors with moderate to strong membranous staining in ⩾ 1% tumor cells per section were scored as positive Globo H expression. Driver mutations including EGFR, KRAS, BRAF were detected by direct sequencing, while ALK, PI3KCA, FGFR1 and PD-L1 expression was detected by immunohistochemical (IHC) staining., Results: Positive Globo H expression was detected in 88 of the 228 (38.6%) patients. These included 51 of 139 (36.7%) patients with ADC and 37 of 89 (41.6%) patients with SqCC. Positive Globo H expression was significantly associated with EGFR mutation and PD-L1 expression in the ADC group, and PI3KCA overexpression in the SqCC group. The survival analysis showed that Globo H expression was not an independent prognostic factor in stage I NSCLC., Conclusions: Globo H expression was correlated with specific driver mutations in ADC and SqCC NSCLC tumors, as well as PD-L1 status. Immunotherapy targeting Globo H may have potential application in lung cancer treatment.

Introduction: Increased expression of Programmed death ligand-1 (PD-L1) on cancer cells and immune cells predict response to PD-1/PDL1 inhibitors. Data regarding frequency and pattern of PD-L1 expression in NSCLC from India is not available., Objectives: To analyse PD-L1 expression on tumour cells (TC) and immune cells (IC) and to correlate PD-L1 expression with baseline clinico-pathological characteristics, oncogenic drivers and outcome data., Materials and Methods: PD-L1 expression on tumour cells and immune cells was analysed., Results: Eighty-nine cases of resected NSCLC were included. Squamous cell carcinoma was more common than adenocarcinoma. IC were present in almost all cases. Immunopositivity for PD-L1 in TC and IC was 27% and 18% respectively. PD-L1 immunopositivity in TC or IC did not correlate with age, sex, stage or mutation status however sarcomatoid carcinoma and solid predominant adenocarcinomas showed higher positivity rates. PD-L1 immunopositivity in ICs was found to correlate with better disease free survival., Conclusion: PD-L1 immunopositivity was seen in a quarter of NSCLC patients in India. PDL1 positivity on immune cells may be associated with better prognosis in resected NSCLC. However the prognostic value of PD-L1 and clinical response to check point inhibitors in Indian population need to be validated in larger studies., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Regional lymph nodes are affected frequently by melanoma metastasis. Its microenvironment may be associated with tumor progression. We investigated sentinel nodes with and without tumor and negative nodes surrounding positive nodes, looking for patterns related to tumor immune interaction and lymphovascular progression. We quantified programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1, vascular endothelial growth factor (VEGF)-A/VEGF-C expressions in lymph nodes of 103 patients who underwent sentinel lymph node biopsy. Two groups were studied: negative sentinel lymph nodes and positive ones. Negative lymph nodes of sequential lymphadenectomy from positive cases were also studied. Markers were assessed by immunohistochemistry. Results were related to clinical/histological outcomes. VEGF-A/VEGF-C analysis showed higher positivity in metastatic nodes and higher positivity in the surrounding negative nodes from positive cases in comparison with nonmetastatic patients. Programmed cell death-ligand 1, studied only in metastasis, presented high positivity, not associated with prognosis. PD-1 expressions were similar in the groups with a 1% cutoff and higher in the metastasis with a 5% cutoff. Higher VEGF-A expression was related to higher pathological stages. PD-1 expression in the lymph node was associated with higher survival. Other clinical and histopatological variables were not associated with marker expression patterns. VEGF-A and VEGF-C expressions in lymph nodes were associated with the presence of lymph node metastasis. PD-1 expression in the lymph node was related to higher survival rates and this should be explored in the context of adjuvant immunotherapy.

Purpose: We investigated the prognostic value of PD-1 and PD-L1 expression in patients with high grade upper tract urothelial carcinoma., Materials and Methods: Tissue microarrays of 423 patients treated with extirpative surgery for high grade upper tract urothelial carcinoma from the International Upper Tract Urothelial Carcinoma collaboration were stained for PD-1 and PD-L1 using antibodies, including Cell Marque™ NAT105 diluted 1:250 and prediluted E1L3N® via immunohistochemistry. A 1% or greater staining rate of tumor infiltrating lymphocytes (PD-1) and tumor cells (PD-L1) was considered positive. Univariate and multivariate analyses were performed to assess independent prognosticators of survival outcomes., Results: Median patient age was 70.0 years and median followup was 37.0 months. PD-1 and PD-L1 were positive in 37.2% and 26.2% of patients, respectively. PD-1 positivity was significantly associated with adverse pathological characteristics while PD-L1 positivity was associated with favorable pT stage. On univariate analysis PD-1 expression was associated with worse recurrence-free, cancer specific and overall survival. On multivariate analysis PD-1 expression was an independent prognosticator of cancer specific survival (HR 1.7, 95% CI 1.03-2.66, p = 0.039) and overall survival (HR 1.5, 95% CI 1.05-2.24, p = 0.029) but not recurrence-free survival (HR 1.4, 95% CI 0.9-2.16, p = 0.139). On univariate analysis PD-L1 expression was not significantly associated with survival outcomes. However, on multivariate analysis in patients with organ confined disease (pT2 or less, pN0/x and cM0), PD-L1 positivity was an independent prognosticator of recurrence-free survival (HR 0.2, 95% CI 0.06-0.98, p = 0.046) and overall survival (HR 0.3, 95% CI 0.11-0.63, p = 0.003)., Conclusions: PD-1 positivity of tumor-infiltrating lymphocytes was associated with adverse pathological criteria and independent prognostication of worse survival outcomes. PD-L1 positivity of tumor cells was an independent prognosticator of favorable survival outcomes in cases of organ confined disease., (Copyright © 2017. Published by Elsevier Inc.)

Oral tongue squamous cell carcinoma (OTSCC) is the most common oral cavity tumor. In this study, we examined the basis for the activity of programmed cell death protein (PD-1)-based immune checkpoint therapy that is being explored widely in head and neck cancers. Using multispectral imaging, we systematically investigated the OTSCC tumor microenvironment (TME) by evaluating the frequency of PD-1 expression in CD8 + , CD4 + , and FoxP3 + tumor-infiltrating lymphocytes (TIL). We also defined the cellular sources of PD-1 ligand (PD-L1) to evaluate the utility of PD-1:PD-L1 blocking antibody therapy in this patient population. PD-L1 was expressed in 79% of the OTSCC specimens examined within the TME. Expression of PD-L1 was associated with moderate to high levels of CD4 + and CD8 + TILs. We found that CD4 + TILs were present in equal or greater frequencies than CD8 + TILs in 94% of OTSCC and that CD4 + FOXP3neg TILs were colocalized with PD-1/PD-L1/CD68 more frequently than CD8 + TILs. Both CD4 + PD1 + and CD8 + PD1 + TILs were anergic in the setting of PD-L1 expression. Overall, our results highlight the importance of CD4 + TILs as pivotal regulators of PD-L1 levels and in determining the responsiveness of OTSCC to PD1-based immune checkpoint therapy. Cancer Res; 77(22); 6365-74. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Objectives: Programmed death ligand 1 (PD-L1) expression in pancreatic ductal adenocarcinoma (PDA) has been described, but unselected PDAs have shown limited clinical responsiveness to anti-programmed death 1 (PD-1)/PD-L1 therapy., Methods: We studied 24 cases of undifferentiated pancreatic carcinoma (UPC) using immunohistochemistry for PD-L1 (E1L3N clone), CD3, CD20, CD68, and DNA mismatch repair proteins in this study. Slides were scored for extent of PD-L1 expression on tumor cells and tumor-infiltrating immune cells., Results: PD-L1 expression was more frequent in UPCs than in PDAs (63% vs 15%, P < .01). The extent of PD-L1 expression was greater in UPCs, with 13 (87%) of 15 cases containing 10% or more positive tumor cells compared with three of seven PDAs (P = .05). Both tumor groups showed similar numbers of tumor-infiltrating T cells, B cells, and macrophages., Conclusions: UPC is enriched for PD-L1 expression in frequency and extent, relative to conventional PDA. Anti-PD-1/PD-L1 agents may represent a valuable therapeutic approach for this subset of highly aggressive pancreatic carcinoma., (© American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Introduction: Pulmonary Sarcomatoid Carcinoma (PSC) is a rare subset of NSCLC, associated with worse prognosis and resistant to platinum-based regimens. Recent investigations have shown high levels of PD-L1 expression in PSC, providing a rationale for the potential use of immunotherapy. In this study, we investigated whether the PD-L1 expression was related to clinico-pathologic and molecular characteristics., Materials and Methods: Fortythree surgically-resected PSCs were selected from 2006 to 2014 and clinical information retrieved. PD-L1 expression was analyzed by immunohistochemistry and correlated with the clinic-pathologic features and driver gene mutations analyzed by Next-Generation-Sequencing. Correlation of clinical, pathological and genetic variants with PD-L1 expression positivity were tested by Fisher's exact test analysis., Results: About 25% of PSCs showed a significant expression of PD-L1 (positive staining defined as staining in ≥10% of tumor cells). 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). Furthermore, PD-L1 expression was significantly associated with the overall mutational load of the tumors (PD-L1 positivity only in PSCs with at least one mutational event) and in particular with the presence of KRAS mutation (PD-L1 positive in 44.4% of KRAS-Mut PSCs vs 12.0% in KRAS-Wild PSCs). The correlation between PD-L1 expression and KRAS-mutation were found at univariate analysis (p=0.031), even considering PD-L1 as a continuous variable (p=0.018), and confirmed at multivariate analysis (p=0.035). The mutational status of the other genes explored in the NGS-panel (EGFR, APC, PTEN, PIK3CA, TP53 and STK11) did not correlate with PD-L1 expression., Conclusions: PD-L1 expression significantly correlates with overall mutational load and KRAS mutational status in pulmonary sarcomatoid carcinomas., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Recent studies have reported the associations between programmed death-ligand 1 (PD-L1) or PD-L2/PD-1 pathways and pro-angiogenic genes including hypoxia-inducible factors (HIFs) and vascular endothelial growth factor (VEGF) in several malignancies. However, no study has examined the relationship or prognostic implication of PD-L1, PD-L2, PD-1, VEGF expression, and microvessel density (MVD) in classical Hodgkin lymphoma (cHL) patients. Diagnostic tissues from 109 patients with doxorubicin, bleomycin, vinblastine, and dacarbazine-treated cHL were evaluated retrospectively by immunohistochemical analysis for PD-L1, PD-L2, PD-1, VEGF expression, and for CD31 expression as a measure of MVD. There was a positive correlation between PD-L1 and VEGF expression (P = 0.008) and additionally between PD-L2 and VEGF expression (P = 0.001). The mean MVD in tumors positive for both PD-L1 and VEGF was significantly (P = 0.022) higher than the mean MVD in tumors negative for both markers. High PD-1 expression group had lower (P = 0.019) 5-year overall survival rate than low PD-1 expression group. Multivariate analysis revealed that PD-1 was an independent prognostic factor for cHL with significance (P = 0.026). However, PD-L1, PD-L2, and VEGF expression had no prognostic impact. Our data confirmed the positive correlations between PD-L1, VEGF, or MVD. Our findings provided evidence supporting new therapeutic approaches including combinations of anti-PD-L1/PD-1 and anti-VEGF therapy in addition to the current standard regimen for cHL.

Clear cell carcinoma represents a distinct histologic type of müllerian carcinoma that is resistant to conventional chemotherapy. Expression of programmed cell death ligand (PD-L1) has been associated with immune evasion in numerous tumor types and may be used to identify patients who will benefit from targeted immunotherapy, particularly in the setting of mismatch repair defects. We evaluated PD-L1 expression in 23 ovarian clear cell carcinomas and 21 endometrial clear cell carcinomas, and correlated expression with mismatch repair status. Tumor PD-L1 staining was seen in 43% of ovarian tumors and 76% of endometrial tumors, including 71% of cases (67% of ovarian and 75% of endometrial) with mismatch repair defects. Extensive tumoral staining (>50%) was seen in only one case (an endometrial case with MSH6 loss). However, tumoral PD-L1 expression remained common in mismatch repair-intact tumors and mismatch repair status was not significantly correlated with PD-L1 expression. The increased incidence of PD-L1 positivity in tumor cells (P=0.04) in endometrial vs ovarian clear cell carcinomas suggests differences in the tumor microenvironment of these histologically and molecularly similar tumors that may inform treatment options. These results suggest that clear cell histology may be a useful susceptibility marker for immunotherapy targeting the PD-1/PD-L1 axis irrespective of mismatch repair status, particularly in endometrial carcinomas.

In summary, the PD-L1 biomarker discussed here highlights the importance of understanding the practice of IHC. This can be used to the patients advantage, with appropriate usage. The currently available literature on PD-L1 IHC from a methodologic point of view has not shown that different assays are comparable. The route of laboratory developed test and commercial test validation is the same: challenging and complex. Executing this process along proper methodologic lines is needed to ensure that patients receive the most accurate and representative test outcomes., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Epithelioid peritoneal malignant mesothelioma (EPMM) is the most common subtype of this aggressive tumor. We compared two antibodies against PD-L1, a recent theranostic biomarker, and evaluated the prognostic value of PD-L1 expression by mesothelial and immune cells in EPMM., Methods: Immunohistochemistry was performed on 45 EPMM. Clinical and pathological data were extracted from the RENAPE database. Using E1L3N and SP142 clones, inter-observer agreement, PD-L1 expression by mesothelial and immune cells and inter-antibody agreement were evaluated. The prognostic relevance of PD-L1 expression was evaluated in 39 EPMM by univariate and multivariate analysis of overall survival (OS) and progression-free survival (PFS)., Results: Inter-observer agreement on E1L3N immunostaining was moderate for mesothelial and immune cells, and fair for mesothelial and poor for immune cells using SP142. Using E1L3N, 31.1% of mesothelial and 15.6% of immune cells expressed PD-L1, and 22.2% of mesothelial and 26.7% of immune cells using SP142. Inter-antibody agreement was moderate. In most positive cases, 1-5% of tumor cells were positive. Using E1L3N, PD-L1 expression by lymphocytes was associated with better OS and PFS by both univariate and multivariate analysis. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy predicted better prognosis than other treatments. Solid subtype was an independent prognostic factor for worse OS., Conclusion: E1L3N appeared easier to use than SP142 to evaluate PD-L1 expression. A minority of EPMM expressed PD-L1, and only a few cells were positive. PD-L1 expression by immune cells evaluated with E1L3N was an independent prognostic factor in EPMM., (Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Aim: The present work aims to evaluate the presence of stromal tumour-infiltrating lymphocytes (TILs) and programmed cell death-ligand 1 (PDL1) expression in breast carcinomas and their correlation with available clinicopathological features., Methods: Two independent series of invasive breast cancer (IBC), one including ductal carcinoma in situ (DCIS) pair-matched cases, were selected, and quantification of TILs was accomplished in each case. Immunohistochemistry was also performed to evaluate the expression of PDL1., Results: In both cohorts evaluated, increased stromal TILs and PDL1 expression were present in about 10% of IBCs, being significantly associated with each other and both with grade 3 and triple-negative subtype. We observed a similar distribution of stromal TILs and PDL1 expression between DCIS and IBC. Finally, we observed that increased stromal TILs and PDL1 expression were significantly associated with cancer stem cell (CSC) markers, basal cell markers and vimentin expression. Interestingly, in IBC cases with vimentin expression, increased stromal TILs, as well as decreased PDL1 expression, disclosed a better clinical outcome, independently of the main classical BC prognostic factors., Conclusions: We have confirmed the association of stromal TILs and PDL1 expression with aggressive forms of BC and that both are already found in in situ stages. We also showed that stromal TILs and PDL1 expression are associated with clinical outcome in cases enriched for a mesenchymal immunophenotype. We describe for the first time a close relationship between CSC markers and PDL1 expression., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Introduction: The extent to which intratumoral heterogeneity of programmed death ligand 1 (PD-L1) expression causes discordance of PD-L1 expression between paired samples remains unclear. Here, PD-L1 status was compared between whole sections from NSCLCs and the corresponding tissue microarrays (TMAs) serving as surrogate biopsy specimens., Methods: PD-L1 expression was evaluated by 22C3 immunohistochemistry assay on 190 archival surgical specimens and matched to the TMA results. PD-L1 expression was determined by the tumor proportion score (TPS) and classified as TPS lower than 1%, TPS of 1% to 49%, and TPS of 50% or higher. Agreement statistics were used., Results: The percentage of PD-L1 expression on tumor cells differed greatly between individual TMAs and matched surgical specimens. When PD-L1 TPS was adopted, a total of 36 of 190 discordance cases (18.9%) were observed, with a κ-value of 0.630 between paired samples. The TMAs underestimated or overestimated PD-L1 status in 19 of 36 (52.8%) and 17 of 36 (47.2%) of the matched surgical specimens, respectively (p = 0.118). The discordance rate was much lower in cases with a PD-L1 TPS lower than 1% compared with in cases with a TPS of 1% to 49% and TPS of 50% or higher (18.4% versus 56.7% and 43.3%, p < 0.001). When a TPS of 50% or higher was used as the cutoff, the discordance rate of PD-L1 TPS less than 50% was further reduced to 7.5%. Such discrepancies were due mainly to intratumoral heterogeneity of PD-L1 expression and nonsignificant association with clinicopathological features., Conclusions: PD-L1 expression in TMAs correlates moderately well with that in the corresponding surgical specimens, indicating that evaluating PD-L1 expression in diagnostic biopsy specimens could be misleading in defining sensitivity to pembrolizumab treatment yet may be reliable as a way to exclude patients with a PD-L1 TPS less than 50% from first-line pembrolizumab treatment., (Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Introduction: PD-L1 is established as a predictive marker for therapy of non-small cell lung cancer with pembrolizumab. Furthermore, PD-L1 positive melanoma has shown more favorable outcomes when treated with anti-PD1 antibodies and dacarbazine compared to PD-L1 negative melanoma. However, the role of PD-L1 expression with regard to response to checkpoint inhibition with anti-CTLA-4 is not clear, yet. In addition, the lack of standardization in the immunohistochemical assessment of PD-L1 makes the comparison of results difficult. In this study, we investigated the PD-L1 gene expression with a new fully automated technique via RT-PCR and correlated the findings with the response to the anti-CTLA-4 antibody ipilimumab., Materials and Methods: Within a retrospective multi-center trial, PD-L1 gene expression was evaluated in 78 melanoma patients in a total of 111 pre-treatment tumor samples from 6 skin cancer centers and analyzed with regard to response to ipilimumab. For meaningful statistical analysis, the cohort was enriched for responders with 30 responders and 48 non-responders. Gene expression was assessed by quantitative RT-PCR after extracting mRNA from formalin-fixed paraffin embedded tumor tissue and correlated with results from immunohistochemical (IHC) stainings., Results and Discussion: The evaluation of PD-L1 expression based on mRNA level is feasible. Correlation between PD-L1 expression as assessed by IHC and RT-PCR showed varying levels of concordance depending on the antibody employed. RT-PCR should be further investigated to measure PD-L1 expression, since it is a semi-quantitative method with observer-independent evaluation. With this approach, there was no statistical significant difference in the PD-L1 expression between responders and non-responders to the therapy with ipilimumab. The evaluation of PD-L1 expression based on mRNA level is feasible. Correlation between PD-L1 expression as assessed by IHC and RT-PCR showed varying levels of concordance depending on the antibody employed. RT-PCR should be further investigated to measure PD-L1 expression, since it is a semi-quantitative method with observer-independent evaluation. With this approach, there was no statistical significant difference in the PD-L1 expression between responders and non-responders to the therapy with ipilimumab.

Cancer cells exploit the expression of the programmed death-1 (PD-1) ligand 1 (PD-L1) to subvert T-cell-mediated immunosurveillance. The success of therapies that disrupt PD-L1-mediated tumour tolerance has highlighted the need to understand the molecular regulation of PD-L1 expression. Here we identify the uncharacterized protein CMTM6 as a critical regulator of PD-L1 in a broad range of cancer cells, by using a genome-wide CRISPR-Cas9 screen. CMTM6 is a ubiquitously expressed protein that binds PD-L1 and maintains its cell surface expression. CMTM6 is not required for PD-L1 maturation but co-localizes with PD-L1 at the plasma membrane and in recycling endosomes, where it prevents PD-L1 from being targeted for lysosome-mediated degradation. Using a quantitative approach to profile the entire plasma membrane proteome, we find that CMTM6 displays specificity for PD-L1. Notably, CMTM6 depletion decreases PD-L1 without compromising cell surface expression of MHC class I. CMTM6 depletion, via the reduction of PD-L1, significantly alleviates the suppression of tumour-specific T cell activity in vitro and in vivo. These findings provide insights into the biology of PD-L1 regulation, identify a previously unrecognized master regulator of this critical immune checkpoint and highlight a potential therapeutic target to overcome immune evasion by tumour cells.

The clinical benefit for patients with diverse types of metastatic cancers that has been observed upon blockade of the interaction between PD-1 and PD-L1 has highlighted the importance of this inhibitory axis in the suppression of tumour-specific T-cell responses. Notwithstanding the key role of PD-L1 expression by cells within the tumour micro-environment, our understanding of the regulation of the PD-L1 protein is limited. Here we identify, using a haploid genetic screen, CMTM6, a type-3 transmembrane protein of previously unknown function, as a regulator of the PD-L1 protein. Interference with CMTM6 expression results in impaired PD-L1 protein expression in all human tumour cell types tested and in primary human dendritic cells. Furthermore, through both a haploid genetic modifier screen in CMTM6-deficient cells and genetic complementation experiments, we demonstrate that this function is shared by its closest family member, CMTM4, but not by any of the other CMTM members tested. Notably, CMTM6 increases the PD-L1 protein pool without affecting PD-L1 (also known as CD274) transcription levels. Rather, we demonstrate that CMTM6 is present at the cell surface, associates with the PD-L1 protein, reduces its ubiquitination and increases PD-L1 protein half-life. Consistent with its role in PD-L1 protein regulation, CMTM6 enhances the ability of PD-L1-expressing tumour cells to inhibit T cells. Collectively, our data reveal that PD-L1 relies on CMTM6/4 to efficiently carry out its inhibitory function, and suggest potential new avenues to block this pathway.

Background and Purpose: We investigated the link between the radiosensitivity gene signature and programmed cell death ligand 1 (PD-L1) status and clinical outcome in order to identify a group of patients that would possibly receive clinical benefit of radiotherapy (RT) combined with anti-PD1/PD-L1 therapy., Material and Methods: We validated the identified gene signature related to radiosensitivity and analyzed the PD-L1 status of invasive breast cancer in The Cancer Genome Atlas (TCGA) dataset. To validate the gene signature, 1045 patients were selected and divided into two clusters using a consensus clustering algorithm based on their radiosensitive (RS) or radioresistant (RR) designation according to their prognosis. Patients were also stratified as PD-L1-high or PD-L1-low based on the median value of CD274 mRNA expression level as surrogates of PD-L1., Results: Patents assigned to the RS group had decreased risk of recurrence-free survival (RFS) rate than patients in the RR group by univariate analysis (HR 0.45, 95% CI 0.25-0.81, p=0.008) only when treated with RT. The RS group was independently associated with the PD-L1-high group, and CD274 mRNA expression was significantly higher in the RS group (p<0.001) than the RR group. In the PD-L1-high group, the RS group was associated with better RFS compared to the RR group (HR 0.37, 95% CI 0.16-0.87, p=0.022) in multivariate analysis. The level of PD-L1 expression may represent the immunogenicity of tumors, and thus, we speculated that the PD-L1-high group had more immunogenic tumors, which could be more sensitive to radiation-induced immunologic cell death., Conclusion: We first evaluated the predictive value of the radiosensitivity gene signature and described a relationship with this radiosensitivity gene signature and PD-L1. The radiosensitivity gene signature and PD-L1 status were important factors for prediction of the clinical outcome of RT in patients with invasive breast cancer and may be used for selecting patients who will benefit from RT combined with anti-PD1/PDL1 therapy., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Introduction: The upregulation of programmed death ligand 1 (PD-L1) is found in many cancers and contributes to evasion of the host's immune defense. In malignant pleural mesothelioma (MPM), PD-L1 expression is associated with the nonepithelioid histological subtype and poor prognosis, but the pathways involved in control of PD-L1 expression in MPM are poorly understood. To address one possible means of PD-L1 regulation we investigated the relationship between dysregulated microRNA levels and PD-L1 expression., Methods: PD-L1 expression was analyzed by immunohistochemistry in tissue microarrays prepared from samples from patients undergoing an operation (pleurectomy with or without decortication). MicroRNA expression was analyzed by reverse-transcriptase quantitative polymerase chain reaction. Regulation of PD-L1 expression in cell lines was assessed after transfection with microRNA mimics and small interfering RNAs. Interaction between microRNAs and PD-L1 was analyzed by using argonaute-2 immunoprecipitation and a luciferase reporter assay., Results: In a series of 72 patients with MPM, 18 (25%) had positive PD-L1 staining, and this was more common in patients with the nonepithelioid subtype (p = 0.01). PD-L1 expression was associated with poor survival (median overall survival 4.0 versus 9.2 months with positive versus negative PD-L1 expression [p < 0.001]), and in multivariate analyses, PD-L1 expression remained a significant adverse prognostic indicator (hazard ratio = 2.2, 95% confidence interval: 1.2-4.1, p < 0.01). In the same patient series, PD-L1 expression was also associated with downregulation of microRNAs previously shown to have tumor suppressor activity in MPM. The median microRNA expression levels of miR-15b, miR-16, miR-193a-3p, miR-195, and miR-200c were significantly lower in the PD-L1-positive samples. Transfecting MPM cell lines with mimics corresponding to miR-15a and miR-16, both of which are predicted to target PD-L1, led to downregulation of PD-L1 mRNA and protein. In addition, miR-193a-3p, with an alternative G-U-containing target site, also caused PD-L1 downregulation., Conclusions: Together, these data suggest that tumor suppressor microRNAs contribute to the regulation of PD-L1 expression in MPM., (Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Background: Binding of tumor-expressed programmed cell death ligand 1 (PD-L1) to the programmed cell death 1 (PD-1) surface receptor blocks T-cell activation thereby leading to immune evasion. Tumor PD-L1 expression has been associated with poor outcome in a wide variety of cancers; however, data in cutaneous squamous cell carcinoma (cSCC) are scarce and conflicting., Objective: To investigate the relationship of tumor PD-L1 expression with the clinicopathologic features and prognosis of cSCC., Methods: PD-L1 expression was analyzed by immunohistochemistry on paraffin-embedded tissue samples from 100 patients with cSCC. Cumulative/dynamic receiver operating characteristic curve was used to determine the optimal PD-L1 threshold. Kaplan-Meier estimators and Cox proportional hazards regression models were also used., Results: On the basis of cumulative/dynamic receiver operating characteristic curves, we defined the cut-off score for PD-L1 expression as ≥25% of tumor cells positively stained. PD-L1 expression was a significant risk factor for nodal metastasis with crude and adjusted hazard ratios of 3.39 (1.71-6.65) and 6.54 (2.28-18.78), respectively., Limitations: This is a retrospective study limited to cSCC of the head and neck., Conclusion: These findings indicate that tumor PD-L1 expression predicts increased risk for nodal metastasis in patients with cSCC., (Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Background and Purpose: We recently reported a time-sensitive, cooperative, anti-tumor effect elicited by radiation (RT) and intra-tumoral-immunocytokine injection in vivo. We hypothesized that RT triggers transcriptional-mediated changes in tumor expression of immune susceptibility markers at delayed time points, which may explain these previously observed time-dependent effects., Materials and Methods: We examined the time course of changes in expression of immune susceptibility markers following in vitro or in vivo RT in B78 murine melanoma and A375 human melanoma using flow cytometry, immunoblotting, and qPCR., Results: Flow cytometry and immunoblot revealed time-dependent increases in expression of death receptors and T cell co-stimulatory/co-inhibitory ligands following RT in murine and human melanoma. Using high-throughput qPCR, we observed comparable time courses of RT-induced transcriptional upregulation for multiple immune susceptibility markers. We confirmed analogous changes in B78 tumors irradiated in vivo. We observed upregulated expression of DNA damage response markers days prior to changes in immune markers, whereas phosphorylation of the STAT1 transcription factor occurred concurrently with changes following RT., Conclusion: This study highlights time-dependent, transcription-mediated changes in tumor immune susceptibility marker expression following RT. These findings may help in the design of strategies to optimize sequencing of RT and immunotherapy in translational and clinical studies., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aims: PD-1/PD-L1 checkpoint immunotherapy has been proposed recently as a promising treatment in relapsed/refractory disease, used eventually in combination with traditional chemotherapy in different cancer settings. To date, no data are available concerning PD-L1 expression in ampulla of Vater carcinoma and its pre-invasive lesions., Methods and Results: We assessed the immunohistochemical expression of PD-L1 in a series of 26 ampullary adenocarcinomas, 50 ampullary dysplastic lesions and 10 normal duodenal mucosa samples. Moreover, in all cases DNA mismatch repair proteins status was investigated. PD-L1 was expressed in seven of 26 (26.9%) invasive carcinomas and three of 50 (6.0%) dysplastic samples. Most of the PD-L1-positive tumours (seven of 10) were intestinal-type and poorly differentiated (G3). The number of PD-L1-positive stromal lymphoid cells was significantly higher in dysplastic and invasive lesions than in the normal samples (P = 0.011). Nineteen dysplastic lesions and eight invasive carcinomas did not show any evident epithelial or stromal PD-L1 expression. Four of the carcinomas were mismatch repair-deficient and two of these were PD-L1-positive. Furthermore, mismatch repair-deficient lesions showed a significantly higher average of PD-L1-positive stromal lymphoid cells than those of neoplastic PD-L1-negative samples (62.8 versus 21.6; P < 0.001)., Conclusions: The present results suggest a role of the PD-1/PD-L1 axis in ampullary adenocarcinomas, and therefore this may also prompt consideration of checkpoint immunotherapy as a novel promising treatment for these tumours., (© 2017 John Wiley & Sons Ltd.)

Background: The prognostic role of programmed death ligand 1 (PDL1), CD8, and forkhead box p3 (FoxP3) expression in desmoplastic melanomas is unclear., Methods: We correlated PDL1, p53, and Ki-67 expression with CD8 + and FoxP3 + immune infiltrates with clinicopathologic variables and patient outcomes in a series of 66 desmoplastic melanomas., Results: Tumoral PDL1 expression (≥25%), which was seen in 21% of patients (14 of 66), significantly correlated with mixed histology, tumor thickness, mitoses, recurrence, and metastasis. According to linear regression analysis, tumoral PDL1 expression correlated with thickness (P = .0041); p53 expression (P = .019); Ki-67 proliferation index (P = .0018); and tumoral CD8 (P = .0084), stromal CD8 (P < .0001), and FoxP3 (P < .0001) T-cell counts. According to univariate analyses, PDL1 expression of 25% or higher correlated with shorter progression-free survival (P < .0001) and melanoma-specific survival (P = .034). According to multivariate analyses, PDL1 expression of 25% or more (P = .026) and mixed histology (P = .039) independently predicted shorter progression-free survival, and presence of lymphovascular invasion predicted shorter overall survival (P = .018)., Limitations: Small study size., Conclusion: Tumoral and stromal CD8 + and FoxP3 + lymphocyte counts correlated with tumoral PDL1 expression, which is supportive of an adaptive immune response. PDL1 expression in desmoplastic melanoma was associated with tumor aggressiveness and progression. Although PDL1 expression is typically low in melanoma, its frequency and level of expression in desmoplastic melanoma may identify a subset of melanomas that are likely to respond to immunotherapy., (Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Aims: During recent years, immune checkpoint inhibition has proved to be effective in several solid malignancies. The aim of this study was to identify novel targets for immunotherapy in anaplastic thyroid cancer by analysis of the expression of tumour antigens for which therapeutic agents are available., Method and Results: By immunohistochemistry we observed tumoral expression of CD70 in 49% of cases. Expression of its receptor, CD27, was present mainly in lymphocytes surrounding and infiltrating the tumour and observed only rarely in tumour cells. CD70 expression was associated with the presence of a precursor papillary thyroid carcinoma and the presence of BRAF V600E mutations in the anaplastic thyroid cancer lesion. Furthermore, the expression of CD70 seems stable during progression of the disease. Tumoral expression of programmed cell death ligand 1 (PD-L1) was found in 28.6% of the anaplastic thyroid cancer cases. Programmed cell death 1 (PD-1), the receptor of PD-L1, was not expressed on the tumour cells. No association between CD70 expression and PD-L1 expression could be demonstrated., Conclusion: These data suggest that targeted immunotherapy for CD70/CD27 and PD-L1/PD-1 might be promising in anaplastic thyroid cancer. However, as a low amount of tumour-infiltrating lymphocytes was observed in most lesions, combined therapy with agents enhancing the invasion of lymphocytes in the tumour region needs to be considered., (© 2017 John Wiley & Sons Ltd.)

Aims: To investigate the expression of the programmed cell death 1 (PD-1) receptor-programmed cell death ligand 1 (PD-L1) pathway and the clinicopathological characteristics in extrahepatic cholangiocarcinoma (eCCA)., Methods and Results: Tissue samples from patients with eCCA [n = 69; perihilar cholangiocarcinoma (CCA), 40; and distal CCA, 29] who underwent surgical resection in the period from 2007 to 2015 were evaluated for PD-1, PD-L1, CD3 and CD163 expression, and correlations with clinicopathological characteristics, including survival data, were determined. PD-L1 was found on both tumour cells of eCCA (8/69, 11.6%) and tumour-associated macrophages (21/69, 30.4%). Significant correlations of PD-L1 expression on cancer cells with venous invasion (P = 0.031) and poor differentiation of the tumour (P = 0.048) were observed. In 19 of 69 (27.5%) samples, tumour-infiltrating lymphocytes (TILs) expressed PD-1, whereas infiltration with CD3-positive and CD163-positive cells was found in 63 of 69 (91.3%) and 68 of 69 (98.6%) cases, respectively. The presence of fewer than five CD3-positive cells per high-power field was significantly correlated with poorer differentiation (P = 0.015) and venous invasion (P < 0.001) of CCA. PD-L1 expression was not correlated with patient survival, but PD-L1 expression on tumour cells combined with low infiltration of CD3-positive TILs was associated with an unfavourable outcome (P = 0.027)., Conclusion: Only a small number of eCCA patients are PD-L1-positive, which might be important for future application of PD-1/PD-L1-targeted immune-modulating therapy in these patients. A small subgroup of eCCAs with PD-L1 expression and low lymphocytic infiltration showed more invasive growth and worse overall survival., (© 2017 John Wiley & Sons Ltd.)

Neuroendocrine neoplasms (NENs) are rare, heterogeneous and ubiquitous tumors commonly localized in the gastrointestinal tract, lung, and pancreas. The clinical behavior of NEN is highly unpredictable; in fact, low-grade cases can unexpectedly be associated with metastases. Currently, the 2010 WHO NEN classification employs histological differentiation and the proliferation index for grading tumors but fails to provide reliable prognostic and therapeutic indications. Therefore, there is an urgent need for a better characterization of G2/G3 NENs. Similar to several other tumors, NENs possess immune-escape mechanisms, but very little has yet been done to characterize this crucial aspect. There are no available data describing PD-L1 expression in these tumors. Here we provide, for the first time, evidence of PD-L1 tissue expression in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). PD-L1 expression was significantly associated with a high-grade WHO classification (G3) (P<0.001) but not with gender, primary site, or lymph node status. The PD-L1 positivity rate and signal intensity are directly correlated (P<0.001) with a grade increase from G1 to G3. In particular in G3 cases, we observed a dichotomy between the morphology (WD- and PD-NENs) and Ki67. Moreover, our study demonstrated a significant association with the grade and PD-L1 expression levels in immune-infiltrating cells (P<0.001). In particular, G3 tumors are characterized by strong PD-L1 expression in both the tumor and infiltrating immune cells (P<0.001), reflecting an unfavorable environment for T-cell-mediated tumor aggression. These findings suggest that NENs might acquire resistance to immune surveillance by upregulating PD-L1 and inhibiting peritumoral and intratumoral infiltrating lymphocytes. Here we demonstrate that PD-L1 is currently the best-known biomarker for G3 NENs, becoming the new gold standard for G3 NEN discrimination. Furthermore, pharmacological approaches using anti-PD-1 antibodies may become the logical choice for the treatment of G3 cases with a poor prognosis.

Purpose BIRCH was designed to examine the efficacy of atezolizumab, a humanized anti-programmed death-ligand 1 (PD-L1) monoclonal antibody, in advanced non-small-cell lung cancer (NSCLC) across lines of therapy. Patients were selected on the basis of PD-L1 expression on tumor cells (TC) or tumor-infiltrating immune cells (IC). Patients and Methods Eligible patients had advanced-stage NSCLC, no CNS metastases, and zero to two or more lines of prior chemotherapy. Patients whose tumors expressed PD-L1 using the SP142 immunohistochemistry assay on ≥ 5% of TC or IC (TC2/3 or IC2/3 [TC or IC ≥ 5% PD-L1-expressing cells, respectively]) were enrolled. Atezolizumab 1,200 mg was administered intravenously every 3 weeks. Efficacy-evaluable patients (N = 659) comprised three cohorts: first line (cohort 1; n = 139); second line (cohort 2; n = 268); and third line or higher (cohort 3; n = 252). The primary end point was independent review facility-assessed objective response rate (ORR; Response Evaluation Criteria in Solid Tumors [RECIST] version 1.1). Secondary end points included median duration of response, progression-free survival, and overall survival (OS). Results BIRCH met its primary objective of demonstrating a significant ORR versus historical controls. With a minimum of 12 months of follow-up, the independent review facility-assessed ORR was 18% to 22% for the three cohorts, and 26% to 31% for the TC3 or IC3 subgroup; most responses are ongoing. Responses occurred regardless of EGFR or KRAS mutation status. The median OS from an updated survival analysis (minimum of 20 month follow up) for cohort 1 was 23.5 months (26.9 months for TC3 or IC3 patients); the median OS in cohorts 2 and 3 was 15.5 and 13.2 months, respectively. The safety profile was similar across cohorts and consistent with previous atezolizumab monotherapy trials. Conclusion BIRCH demonstrated responses with atezolizumab monotherapy in patients with PD-L1-selected advanced NSCLC, with good tolerability. PD-L1 status may serve as a predictive biomarker for identifying patients most likely to benefit from atezolizumab.

Purpose: PD-L1 expression in the pretreatment tumor microenvironment enriches for response to anti-PD-1/PD-L1 therapies. The purpose of this study was to quantitatively compare the performance of five monoclonal anti-PD-L1 antibodies used in recent landmark publications. Experimental Design: PD-L1 IHC was performed on 34 formalin-fixed paraffin-embedded archival melanoma samples using the 5H1, SP142, 28-8, 22C3, and SP263 clones. The percentage of total cells (including melanocytes and immune cells) demonstrating cell surface PD-L1 staining, as well as intensity measurements/ H -scores, were assessed for each melanoma specimen using a computer-assisted platform. Staining properties were compared between antibodies. Results: Strong correlations were observed between the percentage of PD-L1(+) cells across all clones studied ( R 2 = 0.81-0.96). When present, discordant results were attributable to geographic heterogeneity of the melanoma tissue section rather than differences in PD-L1 antibody staining characteristics. PD-L1 intensity/ H -scores strongly correlated with percentage of PD-L1(+) cells ( R 2 > 0.78, all clones). Conclusions: The 5H1, SP142, 28-8, 22C3, and SP263 clones all demonstrated similar performance characteristics when used in a standardized IHC assay on melanoma specimens. Reported differences in PD-L1 IHC assays using these antibodies are thus most likely due to assay characteristics beyond the antibody itself. Our findings also argue against the inclusion of an intensity/ H -score in chromogenic PD-L1 IHC assays. Clin Cancer Res; 23(16); 4938-44. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Background: Programmed cell death ligand-1 (PD-L1) expression is a predictive biomarker for anti-PD-1 immunotherapy in non-small cell lung cancer. Different immunohistochemistry (IHC) assays have been developed on histologic material with different cutoffs for positivity. More than one third of the patients are diagnosed on cytology alone. We hypothesized that cytologic cell block material is suitable for PD-L1 analysis., Materials and Methods: Eighty-six paired samples of malignancies from the lung where cytologic cell block and histologic material were available from the same lesion were stained with PD-L1 IHC 28-8pharmDx and PD-L1 IHC 22C3pharmDx. Scorings of like material (cytology or histology) stained with different assays were analyzed in order to evaluate the analytical agreement between assays. Scoring of different materials stained with like assays were analyzed in order to evaluate the agreement between cytology and histology., Results: A high degree of agreement was found between 28-8pharmDx and 22C3pharmDx, whether applied to histologic or cytologic cell blocks, with Pearson R of 0.95. The Pearson R between 2 rounds of assessment of the same assay on the same type of material was also 0.95. The agreement between histologic and cytologic specimens was high with Pearson R 0.87 to 0.89 and overall agreement between 85% and 95%. There was no bias toward lower prevalence of positivity with cytology than with histology. Disagreement was related to heterogeneity of the histologic tumor sample., Conclusion: PD-L1 assessment is feasible on cytologic material with the tested assays using cutoffs for positivity similar to those used on histologic material.

Background: Clear cell renal cell carcinoma (ccRCC) is highly metastatic. Cabozantinib, an anti-angiogenic tyrosine kinase inhibitor that targets c-MET, provided interesting results in metastatic ccRCC treatment., Objective: To understand better the role of c-MET in ccRCC, we assessed its status in a population of patients with metastatic ccRCC., Patients and Methods: For this purpose, tumor samples were analyzed for c-MET expression by immunohistochemistry (IHC), for c-MET copy number alterations by fluorescence in situ hybridization (FISH), and for c-MET mutations by next generation sequencing (NGS) in a retrospective cohort of 90 primary ccRCC of patients with metastases treated by first-line sunitinib. The expression of c-MET was correlated with pathological, immunohistochemical (VEGFA, CAIX, PD-L1), clinical, and molecular criteria (VHL status) by univariate and multivariate analyses and to clinical outcome using Kaplan-Meier curves compared by log-rank test., Results: Of ccRCC, 31.1% had low c-MET expression (absent to weak intensity by IHC) versus 68.9% with high expression (moderate to strong intensity). High expression of c-MET was associated with a gain in FISH analysis (p=0.0284) without amplification. No mutations were detected in NGS. Moreover, high c-MET expression was associated with lymph node metastases (p=0.004), sarcomatoid component (p=0.029), VEGFA (p=0.037), and PD-L1 (p=0.001) overexpression, the only factor that remained independently associated (p<0.001) after logistic regression. No difference was observed in clinical outcomes., Conclusion: This study is the first to analyse c-MET status in metastatic ccRCC. The high expression of c-MET in the majority of ccRCC and its independent association with PD-L1 expression, may suggest a potential benefit from combining c-MET inhibitors and targeted immunotherapy.

Background/aim: Programmed death 1 (PD1) and its ligand programmed death ligand 1 (PDL1) form a pathway which when activated is thought to result in suppression of antitumor adaptive responses, influencing antitumor immunity. With potential targeted therapies emerging against PDL1, we investigated the clinical significance of mRNA expression levels of PD1 and PDL1 in our breast cancer cohort to explore its association with disease progression and prognosis. Previous studies evaluating the expression of PD1 and PDL1 (mRNA or protein) and its association with prognosis in breast cancer showed both positive and negative correlations and hence remain controversial., Materials and Methods: Quantitative polymerase chain reaction was used to determine transcript expression levels of PD1 and PDL1 in a cohort consisting of primary breast cancer tissues (n=127) and matching non-neoplastic background tissues (n=33) with available clinical and pathological information. Two-sample two-tailed t-test, Kaplan-Meier survival analysis and Wilcoxon tests were performed., Results: 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. Higher PDL1 transcript levels were also associated with better overall and disease-free survival. Significantly higher transcript expression levels of PD1 were found in tumor tissue, whilst a general increase in PDL1 expression was found in tumor tissues, although this did not reach statistical significance., Conclusion: Our study demonstrates higher levels of expression of PDL1 are associated with favorable clinical outcome., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose Data suggest that DNA damage by poly (ADP-ribose) polymerase inhibition and/or reduced vascular endothelial growth factor signaling by vascular endothelial growth factor receptor inhibition may complement antitumor activity of immune checkpoint blockade. We hypothesize the programmed death-ligand 1 (PD-L1) inhibitor, durvalumab, olaparib, or cediranib combinations are tolerable and active in recurrent women's cancers. Patients and Methods This phase I study tested durvalumab doublets in parallel 3 + 3 dose escalations. Durvalumab was administered at 10 mg/kg every 2 weeks or 1,500 mg every 4 weeks with either olaparib tablets twice daily or cediranib on two schedules. The primary end point was the recommended phase II dose (RP2D). Response rate and pharmacokinetic analysis were secondary end points. Results Between June 2015 and May 2016, 26 women were enrolled. The RP2D was durvalumab 1,500 mg every 4 weeks with olaparib 300 mg twice a day, or cediranib 20 mg, 5 days on/2 days off. No dose-limiting toxicity was recorded with durvalumab plus olaparib. The cediranib intermittent schedule (n = 6) was examined because of recurrent grade 2 and non-dose-limiting toxicity grade 3 and 4 adverse events (AEs) on the daily schedule (n = 8). Treatment-emergent AEs included hypertension (two of eight), diarrhea (two of eight), pulmonary embolism (two of eight), pulmonary hypertension (one of eight), and lymphopenia (one of eight). Durvalumab plus intermittent cediranib grade 3 and 4 AEs were hypertension (one of six) and fatigue (one of six). Exposure to durvalumab increased cediranib area under the curve and maximum plasma concentration on the daily, but not intermittent, schedules. Two partial responses (≥15 months and ≥ 11 months) and eight stable diseases ≥ 4 months (median, 8 months [4 to 14.5 months]) were seen in patients who received durvalumab plus olaparib, yielding an 83% disease control rate. Six partial responses (≥ 5 to ≥ 8 months) and three stable diseases ≥ 4 months (4 to ≥ 8 months) were seen in 12 evaluable patients who received durvalumab plus cediranib, for a 50% response rate and a 75% disease control rate. Response to therapy was independent of PD-L1 expression. Conclusion To our knowledge, this is the first reported anti-PD-L1 plus olaparib or cediranib combination therapy. The RP2Ds of durvalumab plus olaparib and durvalumab plus intermittent cediranib are tolerable and active. Phase II studies with biomarker evaluation are ongoing.

Recent data supports a potentially significant role for immune checkpoint inhibitors in the treatment of gastric cancer. However, there are few data on the clinical implications of immunotherapy markers in gastric signet-ring cell carcinoma (SRCC). We evaluated the expression of programmed cell death protein-1 (PD-1), programmed cell death ligand 1(PD-L1), infiltration by CD3+ T cell, microsatellite instability (MSI), and Epstein-Barr Virus (EBV), and the relationship of each factor to survival in 89 advanced SRCC patients. All patients received 5-FU-based first-line chemotherapy. PD-L1 and PD-1 were expressed in 40.4% and 18.0% of the patients, respectively. There was a significant correlation between PD-L1 and PD-1 expression (r=0.363, p<0.001). There was loss of at least 1 of the 4 DNA mismatch repair (DNA-MMR) gene proteins in 32.6% of samples. Only 1 case out of 89 was EBV positive, with concurrent PD-L1 positivity, a high degree of CD3+ T cell infiltration and MSI. Increased CD3+ T cells numbers was associated with increased PD-1 expression (r=0.256, p=0.012) and MSI status (r=0.208, p=0.049). High CD3+ T cell infiltration was related to better OS (23.7 months, 95% CI: 19.0-38.0 vs 15.8 months, 95% CI: 13.0-22.0, p=0.033), but was not an independent prognostic factor for survival after multivariate analysis (HR=0.68, 95% CI: 0.42-1.10, p=0.116). CD3+ T cell was more infiltrated in PD-1 positive, tumors with MSI and were associated with better OS, indicating an adaptive immune resistance may be occurring. Further research into the cancer immunotherapy markers of SRCC immune microenvironment may highlight targets for immunotherapy.

Most nasopharyngeal carcinomas (NPCs) in a high-incidence population are driven by Epstein-Barr virus (EBV) infection. EBV-associated malignancies have increased expression of the programmed death-ligand 1 (PD-L1). Immunotherapy agents targeting the PD-1/PD-L1 pathway have achieved durable treatment effects in patients with various cancer types including EBV-associated malignancies. In this study, we sought to investigate PD-L1 expression in a cohort of patients with NPCs from the Philippines. Fifty-six NPCs were studied for PD-L1, p16, and DNA mismatch repair (MMR) deficiency by immunohistochemistry. One case with MMR deficiency was also assessed for microsatellite instability (MSI) by polymerase chain reaction. EBV and human papillomavirus (HPV) status were tested by in situ hybridization. All NPCs were p16 negative. Three of the 56 NPCs (5%) were EBV negative (EBV-) and HPV negative, while one NPC (1/56, 2%) was EBV positive and showed MSI (EBV+/MSI). Positive PD-L1 expression (PD-L1+), defined as membranous staining in ≥1% tumor cells, was seen in 64% (36/56) of NPCs. All three EBV- NPCs were PD-L1+ as was the EBV+/MSI NPC. PD-L1+ was seen significantly more often in NPCs from non-smokers than those from smokers (23/28, 82% vs 9/18, 50%; P = 0.047). PD-L1+ was not associated with pT, pN, distant metastasis, or clinical stage (P > 0.05). PD-L1+ was not associated with overall survival (P = 0.473). In summary, our results show frequent PD-L1 expression in NPCs regardless of EBV status and a preferential PD-L1 expression in non-smokers. MSI and HPV positivity are exceedingly rare in NPCs.

Purpose Blockade of the programmed cell death 1 (PDCD1, PD-1) immune checkpoint pathway can improve clinical outcomes in various malignancies. Evidence suggests that aspirin (a widely used nonsteroidal anti-inflammatory drug) not only prolongs colorectal cancer survival, but can also activate T cell-mediated antitumor immunity and synergize with immunotherapy through inhibition of prostaglandin E2 production. We hypothesized that the survival benefit associated with aspirin might be stronger in colorectal carcinoma with a lower CD274 (PDCD1 ligand 1, PD-L1) expression level that resulted in lower signaling of the immune checkpoint pathway. Patients and Methods Using data from 617 patients with rectal and colon cancer in the Nurses' Health Study and the Health Professionals Follow-Up Study, we examined the association of postdiagnosis aspirin use with patient survival in strata of tumor CD274 expression status measured by immunohistochemistry. We used multivariable Cox proportional hazards regression models to control for potential confounders, including disease stage, microsatellite instability status, CpG island methylator phenotype, long interspersed nucleotide element-1 methylation, cyclooxygenase-2 (PTGS2), and CDX2 expression, and KRAS, BRAF, and PIK3CA mutations. Results The association of postdiagnosis aspirin use with colorectal cancer-specific survival differed by CD274 expression status ( P interaction < .001); compared with aspirin nonusers; multivariable-adjusted hazard ratios for regular aspirin users were 0.16 (95% CI, 0.06 to 0.41) in patients with low CD274 and 1.01 (95% CI, 0.61 to 1.67) in patients with high CD274. This differential association seemed consistent in patients with microsatellite-stable or PIK3CA wild-type disease and in strata of PTGS2 expression, CDX2 expression, tumor-infiltrating lymphocytes, or prediagnosis aspirin use status. Conclusion The association of aspirin use with colorectal cancer survival is stronger in patients with CD274-low tumors than CD274-high tumors. Our findings suggest a differential antitumor effect of aspirin according to immune checkpoint status.

Immunotherapy targeting the programmed death-1 (PD-1) receptor/PD-1 ligand (PD-L1) pathway has shown promising results in several malignancies. However, the prognostic significance of PD-L1 expression remains unknown in patients with upper tract urothelial carcinoma (UTUC). This study aimed to evaluate PD-L1 expression and its association with clinicopathological characteristics and oncological outcomes in UTUC patients. PD-L1 expression on tumor cells and tumor-infiltrating mononuclear cells (TIMCs), and E-cadherin and N-cadherin expression on tumor cells were assessed by immunohistochemistry in a cohort of 162 patients with UTUC. Associations of PD-L1 expression on tumor cells and TIMCs with clinicopathological characteristics and cancer-specific survival (CSS) were evaluated. Out of 162 patients, 20 (12.3%) and 35 (21.6%) had positive PD-L1 expression on tumor cells and TIMCs, respectively. Decreased E-cadherin expression was associated with PD-L1 positivity on tumor cells (P = 0.048) and PD-L1 negativity on TIMCs (P = 0.033). PD-L1 expression on tumor cells was higher in patients with preoperative chronic kidney disease (CKD) stage 4-5 than in those with no CKD or CKD stage 1-3 (P = 0.011). PD-L1 was differentially expressed in tumor cells and TIMCs in UTUC. Multivariate analyses revealed that PD-L1 expression on tumor cells independently predicted shorter CSS (P = 0.012), whereas PD-L1 expression on TIMCs independently predicted longer CSS (P = 0.034).

Purpose: To evaluate the prognostic value and pathobiological significance of Glasgow microenvironment score (GMS), a parameter based on tumor stroma percentage and inflammatory cell infiltration, in gastric cancer., Methods: A total of 225 cases of gastric cancer were histologically reviewed, and GMS was evaluated for each case. The association between GMS and patients' survival was investigated. Then the relationship between GMS and mismatch repair (MMR) status, Epstein-Barr virus (EBV) infection were determined using immunohistochemistry (IHC) and in situ hybridization, and the expression of PD1/PD-L1 was examined. Furthermore, the amount of cancer-associated fibroblasts (CAFs), the content and maturity of collagen components were detected using IHC, Picrosirius Red staining and second harmonic generation imaging., Results: GMS was significantly associated with clinical outcomes of gastric cancer, and multivariate analysis indicated that GMS was an independent factor (HR 1.725, P = 0.002). Low GMS was a manifestation of better prognosis and inflammatory tumor microenvironment, which was related to MMR deficiency (P = 0.042) and EBV infection (P = 0.032), and within this microenvironment, expression of PD-L1 in carcinoma cells (P = 0.030) or in inflammatory cells (P = 0.029) was significantly higher. In contrast, high GMS linked to a poorer survival and desmoplastic stroma, in which there existed markedly increased CAFs and collagen deposition., Conclusion: GMS can serve as a useful prognostic factor for gastric cancer, and according to GMS, the tumor microenvironment in this cancer type may be partially classified as inflammatory or desmoplastic microenvironment that possesses different pathobiological features.

Purpose: To examine oral squamous cell carcinoma (OSCC) specimens for programmed death ligand-1 (PD-L1) expression and presence of programmed death-1 (PD-1)-positive tumor-infiltrating lymphocytes (TILs) and to determine possible clinicopathologic implications. It was hypothesized that PD-L1 expression and PD-1-positive TIL presence in OSCC would have no clinical relevance., Materials and Methods: The authors implemented a retrospective cohort study design. The study cohort was chosen in compliance with predefined inclusion criteria. Demographic, clinical, and histopathologic data were gathered. Tissue microarrays were obtained from paraffin-embedded OSCC specimens and analyzed immunohistochemically for PD-L1 expression and PD-1-positive TIL infiltration. PD-L1 positivity of OSCC specimens served as the predictor variable and neck node metastasis served as the primary outcome variable. Descriptive and inferential statistics were computed and the significance level was set at a P value less than or equal to .05., Results: The study sample was composed of 88 patients (48 men, 40 women; mean age, 61.34 yr). Marked PD-L1 expression was detected in 29% of OSCC specimens (26 of 88) and 83% of specimens (73 of 88) exhibited a high rate of PD-1-positive TIL infiltration. PD-L1 positivity of OSCC samples was significantly associated with the anatomic origin of OSCC (P = .039), presence of cervical metastasis (P = .039), and high PD-L1-positive TIL infiltration (P = .033)., Conclusion: A considerable proportion of OSCCs exhibited marked PD-L1 expression. This could be associated with clinical parameters. PD-L1 expression in OSCC might differ depending on its anatomic origin. PD-1-positive TILs could be detected in most OSCC specimens. These findings might indicate a potential role for the PD-1 and PD-L1 pathway in OSCC., (Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

V-domain Ig suppressor of T cell activation (VISTA), a novel immune checkpoint regulatory molecule, suppresses T cell mediated immune responses. The aim of the present study was to profile the immunological expression, clinical significance and correlation of VISTA in human oral squamous cell carcinoma (OSCC). Human tissue microarrays, containing 165 primary OSCCs, 48 oral epithelial dysplasias and 43 normal oral mucosae, were applied to investigate the expression levels of VISTA, CD8, cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), programmed death ligand 1 (PD-L1), PI3Kα p110, IL13Rα2, phospho-STAT3 at tyrosine 705 (p-STAT3) and myeloid-derived suppressor cell (MDSC) markers (CD11b and CD33) by immunohistochemistry and digital pathology analysis. The results demonstrated that the protein level of VISTA was significantly higher in human OSCC specimens, and that VISTA expression in primary OSCCs was correlated with lymph node status. VISTA expression did not serve as an independent predictor for poor prognosis, while patient subgroup with VISTA high and CD8 low expression (22/165) had significantly poorer overall survival compared with other subgroups based on the multivariate and Cox hazard analyses among the primary OSCC patients in the present cohort. Additionally, the expression of VISTA was significantly correlated with PD-L1, CTLA-4, IL13Rα2, PI3K, p-STAT3, CD11b and CD33 according to Pearson's correlation coefficient test. Taken together, the results indicated that the VISTA high and CD8 low group, as an immunosuppressive subgroup, might be associated with a poor prognosis in primary OSCC. These findings indicated that VISTA might be a potential immunotherapeutic target in OSCC treatment.

Cholangiocarcinoma is an aggressive biliary neoplasm lacking effective therapeutic agents. Immunotherapies targeting the PD-L1/PD-1 immune checkpoint have shown encouraging results in solid and hematologic cancers in clinical trials. Response to these immunomodulators is correlated with PD-L1 expression. Our goal was to characterize PD-L1 expression in intra-hepatic (iCCA) and perihilar (pCCA) cholangiocarcinomas, and to correlate our results with clinicopathological features, density of tumor-infiltrating lymphocytes (TILs) and PD-1 expression.A series of 58 iCCAs and 41 pCCAs was included in the study. PD-L1, PD-1 and CD3 expression was investigated using immunohistochemistry. Density of TILs was evaluated by immunohistochemistry using a quantitative score of CD3-stained intratumoral lymphocytes.PD-L1 expression by neoplastic cells was observed in 9 cases (9%, 5 iCCAs and 4 pCCAs). PD-L1 positive inflammatory cell aggregates were identified in 46% (n = 46) of the cases (31 iCCAs and 15 pCCAs). PD-L1 expression by either neoplastic or inflammatory cells was associated to high density of CD3-positive TILs (p = 0.01 and p = 0.005, respectively). The number of PD-L1 positive inflammatory cell aggregates was higher in tumors with high PD-1 expression (p < 0.0001).Altogether, PD-L1 in iCCA and pCCA is mainly expressed in tumors with high density of TILs. Our results suggest that CCAs with dense intratumoral lymphocytic infiltration might represent good candidates for PD-L1/PD-1 blocking agents.

Many human cancers have been reported to have enhanced expression of the immune checkpoint molecule programmed death-ligand 1 (PD-L1), which binds to programmed cell death-1 (PD-1) expressed on immune cells. PD-L1/PD-1 plays a role in inhibition of antitumor immunity by inducing T cell apoptosis and tolerance. Thus, it is crucial to elucidate mechanisms of PD-L1 expression on cancer cells. ERO1-α is an oxidase located in the endoplasmic reticulum. It is overexpressed in a variety of tumor types and it plays a role in disulfide bond formation in collaboration with PDI. Here, we investigated the influence of ERO1-α on expression of PD-L1 and immune escape. We demonstrated that ERO1-α augmented the expression of PD-L1 via facilitation of oxidative protein folding within PD-L1. In addition, we showed that overexpression of ERO1-α increased HIF-1α protein expression, resulting in an increase of PD-L1 mRNA as well as protein. In clinical cases, we observed that the expression of ERO1-α in triple negative breast cancer was related to the expression of PD-L1. Moreover, apoptosis of Jurkat leukemia T cells, which express PD-1, induced by tumor PD-L1 was inhibited when ERO1-α was depleted. The results suggest that targeting ERO1-α in tumor cells can be a novel approach for cancer immunotherapy. Therefore, the role of ERO1-α in tumor-mediated immunosuppression should be further explored.

Background: The expression of programmed death (PD) ligand 1 (PD-L1) protein expression assessed by immunohistochemistry (IHC) has been correlated with response and survival benefit from anti-PD-1/PD-L1 immune checkpoint inhibitor therapies in advanced non-small cell lung carcinoma (NSCLC). The efficacy of several agents appears correlated with PD-L1 expression. It remains controversial whether PD-L1 is prognostic in NSCLC. We assessed the prognostic value of PD-L1 IHC and its predictive role for adjuvant chemotherapy in early stage NSCLC., Patients and Methods: Tumor sections from three pivotal adjuvant chemotherapy trials (IALT, JBR.10, CALGB 9633) using the E1L3N antibody were studied in this pooled analysis. PD-L1 staining intensity and percentage in both tumor cells (TCs) and immune cells (ICs) were scored by two pathologists. The average or consensus PD-L1 expression levels across intensities and/or percent cells stained were correlated with clinicopathological and molecular features, patient survivals and potential benefit of adjuvant chemotherapy., Results: Results from 982 patients were available for analysis. Considering staining at any intensities for overall PD-L1 expression, 314 (32.0%), 204 (20.8%) and 141 (14.3%) tumor samples were positive for PD-L1 staining on TCs using cut-offs at ≥1%, ≥10% and ≥25%, respectively. For PD-L1 expressing ICs, 380 (38.7%), 308 (31.4%) and 148 (15.1%) were positive at ≥ 1%, ≥10% and 25% cut-offs, respectively. Positive PD-L1 was correlated with squamous histology, intense lymphocytic infiltrate, and KRAS but not with TP53 mutation. EGFR mutated tumors showed statistically non-significant lower PD-L1 expression. PD-L1 expression was neither prognostic with these cut-offs nor other exploratory cut-offs, nor were predictive for survival benefit from adjuvant chemotherapy., Conclusions: PD-L1 IHC is not a prognostic factor in early stage NSCLC patients. It is also not predictive for adjuvant chemotherapy benefit in these patients., (© The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

This study sought to investigate the prevalence of programmed death ligand 1 (PD-L1) and its prognostic value in patients with residual tumors after neoadjuvant chemotherapy (NCT) for locally advanced breast cancer. A total of 309 patients considered as non-pathological complete responders (non-pCR) after NCT followed by mastectomy were selected. The expression of PD-L1 and tumor-infiltrating lymphocytes (TILs) in residual breast cancer cells was assessed by immunohistochemistry in surgical specimens. The median density was used to classify PD-L1 expression from low to high. The prognostic value of various clinicopathological factors was evaluated. The expression of PD-L1 was more commonly observed in patients with low levels of total TILs (p < 0.001), high levels of FOXP3+ TILs (p < 0.001) and low levels of CD8+ TILs (p < 0.001). This served as an independent prognostic factor for both relapse-free survival (Hazard ratio = 1.824, p = 0.013) and overall survival (OS) (Hazard ratio = 2.585, p = 0.001). High expression of PD-L1 was correlated to worse survival, which is most significantly observed in triple-negative patients. Patients classified as PD-L1-high/CD8-low exhibited relatively unfavorable survival, whereas patients with either low expression of PD-L1 or high expression of CD8 had similar outcomes. PD-L1 expression in residual tumor can be used as a prognostic marker in non-pCR patients after receiving NCT for breast cancer, which highlights the importance of immune evasion in the therapeutic vulnerability of chemoresistant cancer cells as well as the potential of anti-PD-L1 treatments in non-pCR responders., (© 2016 UICC.)