Clinical significance of programmed death-1 ligand-1 and programmed death-1 ligand-2 expression in human esophageal cancer

The optimal neoadjuvant treatment of locally advanced esophageal cancer

Esophagectomy is the cornerstone of intentionally curative treatment in patients with locally advanced esophageal cancer. Neoadjuvant treatments have been introduced to minimize the risk of development of locoregional- and/or distant recurrences. Chemotherapy is used based on the results of the MAGIC- and the OEO2-trials and chemoradiotherapy became part of standard treatment after the publication of the CROSS-trial. Although several studies have compared the efficacy of neoadjuvant chemotherapy and chemoradiotherapy, no robust evidence on the optimal neoadjuvant treatment has been obtained as yet. Several studies indirectly comparing both modalities suggest a benefit for chemoradiotherapy in the number of pathologically complete responders, radical resection rate and possibly even in overall survival. Large randomized controlled trials like the Neo-AEGIS-, ESOPEC- and NeXT-trials are currently addressing this topic. A relatively new aspect of esophageal cancer treatment is the administration of monoclonal antibodies. Several monoclonal antibodies have been tested in, mostly, advanced esophageal cancer treatment. Cetuximab has also been tested as addition to neoadjuvant- and definitive treatment in patients with locally advanced esophageal cancer, showing mixed results. This review aims at providing an overview of the currently available neoadjuvant treatments in esophageal cancer.

A review on the interactions between the tumor microenvironment and androgen receptor signaling in prostate cancer

Prostate cancer growth is controlled by androgen receptor signaling via both androgen-dependent and androgen-independent pathways. Furthermore, the prostate is an immune competent organ with inflammatory changes both within the systemic and local environment contributing to the reprogramming of the prostatic epithelium with consistently elevated lymphocyte infiltration and proinflammatory cytokines being found in prostate cancer. The crosstalk between the tumor microenvironment and androgen receptor signaling is complex with both protumorigenic and antitumorigenic roles observed. However, despite an increase in immune checkpoint inhibitors and inflammatory signaling blockades available for a range of cancer types, we are yet to see substantial progress in the treatment of prostate cancer. Therefore, this review aims to summarize the tumor microenvironment and its impact on androgen receptor signaling in prostate cancer.

Expression of PD-L1 Attenuates the Positive Impacts of High-level Tumor-infiltrating Lymphocytes on Prognosis of Triple-negative Breast Cancer

Background: Among all breast cancer subtypes, triple-negative breast cancer (TNBC) has aggressive clinical manifestations including more frequent relapses and metastases. The roles of PD-L1 expression and tumor-infiltrating lymphocytes (TILs) in TNBC clinicopathological behaviors and patients' survival outcomes remain unclear. Methods: TNBC (108 cases) patients with at least 5-year follow-up were analyzed for PD-L1 expression and TILs by immunohistochemistry. We also analyzed the relationships between PD-L1 expression, TILs and clinicopathological characteristics. Furthermore, we explored the effect of PD-L1 expression and TILs on prognosis as illustrated by disease-free survival (DFS). Results: The expression of PD-L1 was related to more aggressive clinicopathological behaviors in TNBC patients including a larger tumor size, higher incidence of PL-1-ALN, more frequent distant metastasis, and a reduced disease-free survival. In contrast, patients with high-level TILs showed less aggressive disease progression hence a better prognosis compared to patients with low-level TILs. Among patients with high-level TILs, PD-L1 expression was correlated with adverse prognosis. Conclusions: Expression of PD-L1 and low-level TILs in TNBC patients were associated with adverse clinical outcomes. However, the positive impact of high-level TILs was attenuated by PD-L1 expression. Our results suggest potential biomarkers for a selection of indicated cases in the TNBC patients for anti-PD-L1/anti-PD1 immunotherapy.

Osteosarcoma cell intrinsic PD-L2 signals promote invasion and metastasis via the RhoA-ROCK-LIMK2 and autophagy pathways

Known as co-stimulatory molecule, programmed death ligand-2 (PD-L2) contributes to T-cell exhaustion by interaction with programmed death-1 (PD-1) receptor, but its tumor cell-intrinsic signal effects have been little investigated. PD-L2 expression was detected by immunohistochemistry in 18 pairs of primary osteosarcoma tissues and matching lung metastasis tissues. We also investigated the effects of PD-L2 knockdown on osteosarcoma both in vitro and in vivo. In our study, PD-L2 expression was elevated in lung metastases compared with primary osteosarcoma according to an immunohistochemistry assay. Wound-healing and transwell assays revealed that PD-L2 knockdown  leaded to inhibition of migration and invasion of human osteosarcoma cells in vitro. Mechanistically, we demonstrated that PD-L2 knockdown attenuated migration and invasion by inactivating RhoA-ROCK-LIMK2 signaling, suppressing epithelial–mesenchymal transition (EMT), and inhibiting autophagy by decreasing beclin-1 expression. In support of these observations, beclin-1 knockdown also inhibited activation of the RhoA-ROCK-LIMK2 pathway, leading to autophagy inhibition-induced blockade of migration and invasion. Depletion of PD-L2 in KHOS cells markedly weakens pulmonary metastatic potential in vivo by orthotopic transplantation of nude mice. Our study reveals a pro-metastatic functional mechanism for PD-L2 in osteosarcoma. Furthermore, we demonstrate a regulatory role for PD-L2 on autophagy, as well as a relationship between autophagy and metastasis in osteosarcoma, which may represent a potential therapeutic target for osteosarcoma.

Programmed death-1 ligands and tumor infiltrating T lymphocytes in primary and lymph node metastasis of esophageal cancer patients

Neoadjuvant chemotherapy (NAC) is administered to many patients with esophageal squamous cell carcinoma (ESCC) prior to surgery, but it is also true that some of these patients demonstrated no response to the therapy following surgery. In addition, the prognosis of advanced case such as ESCC patients with lymph node metastasis has remained relatively low. Programmed death ligand-1 (PD-L1) in conjunction with tumor-infiltrating lymphocytes (TILs) has been studied as a potential mechanism of "immune escape" in several human malignancies. Therefore, in this study, we studied PD-L1 status in carcinoma cells and forkhead box protein 3 (FOXP3) and CD8 status among TILs in the residual tumors of primary and metastatic sites following NAC. We also studied the association of these factors with the clinicopathological findings in 44 patients with ESCC harboring lymph node metastasis. There was discordance in the pathological response to chemotherapy between the primary tumor and lymph node metastasis, and histologically identified resistance to NAC in lymph node metastases tended to be correlated with an adverse clinical outcome (P = 0.0765) than resistance in the primary tumor. Both univariate and multivariate analyses for disease-specific survival (DSS) revealed that the PD-L1 status of carcinoma cells in metastatic lymph nodes and a higher FOXP3/CD8 ratio in the primary tumor were both significantly correlated with an eventual adverse clinical outcome of the patients (P = 0.0178, P = 0.0463, respectively). These results all indicated that the PD-L1 status of carcinoma cells in metastatic lymph nodes and the FOXP3/CD8 ratio in primary tumors could predict eventual clinical outcomes in ESCC patients with NAC.

Met inhibition revokes IFNγ-induction of PD-1 ligands in MET-amplified tumours

BACKGROUND

Interferon-induced expression of programmed cell death ligands (PD-L1/PD-L2) may sustain tumour immune-evasion. Patients featuring MET amplification, a genetic lesion driving transformation, may benefit from anti-MET treatment. We explored if MET-targeted therapy interferes with Interferon-γ modulation of PD-L1/PD-L2 in MET-amplified tumours.

METHODS

PD-L1/PD-L2 expression and signalling pathways downstream of MET or Interferon-γ were analysed in MET-amplified tumour cell lines and in patient-derived tumour organoids, in basal condition, upon Interferon-γ stimulation, and after anti-MET therapy.

RESULTS

PD-L1 and PD-L2 were upregulated in MET-amplified tumour cells upon Interferon-γ treatment. This induction was impaired by JNJ-605, a selective inhibitor of MET kinase activity, and MvDN30, an antibody inducing MET proteolytic cleavage. We found that activation of JAKs/ STAT1, signal transducers downstream of the Interferon-γ receptor, was neutralised by MET inhibitors. Moreover, JAK2 and MET associated in the same signalling complex depending on MET phosphorylation. Results were confirmed in MET-amplified organoids derived from human colorectal tumours, where JNJ-605 treatment revoked Interferon-γ induced PD-L1 expression.

CONCLUSIONS

These data show that in MET-amplified cancers, treatment with MET inhibitors counteracts the induction of PD-1 ligands by Interferon-γ. Thus, therapeutic use of anti-MET drugs may provide additional clinical benefit over and above the intended inhibition of the target oncogene.

PD-L1 expression and its clinicopathological correlation in advanced esophageal squamous cell carcinoma in a Chinese population

Background

Programmed death ligand 1 (PD-L1) is a ligand for the inhibitory programmed cell death protein 1 (PD-1), which are targeted by several anti-PD-1 and PD-L1 drugs for a variety of human cancers. However, only a few studies have evaluated PD-L1 expression in esophageal squamous cell carcinoma (ESCC) with a large Chinese cohort. Our present study is to evaluate the association of PD-L1 expression with clinicopathological features on ESCC.

Methods

Using tissue microarray and immunohistochemistry, PD-L1 expression on tumor cells and tumor-infiltrating immune cells was studied in 378 advanced ESCC patients without neoadjuvant chemoradiotherapy. Its correlation with clinicopathological parameters was analyzed.

Results

PD-L1 was expressed on 29.9% (113/378) ESCC tumor cells and 40.2% (152/378) tumor-infiltrating immune cells. PD-L1 expression in tumor cells was significantly correlated with age, degree of differentiation, T stage, N stage and metachronous hematogenous metastasis, and PD-L1 expression in tumor-infiltrating immune cells was significantly associated with N stage (P < 0.05). Patients with PD-L1 expression in tumor cells had poor disease-free survival (Hazard ratio [HR] = 1.436, P = 0.009). There was a positive association between tumor cells and tumor-infiltrating immune cells for PD-L1 expression (r = 0.16, P = 0.002). However, PD-L1 expression in tumor-infiltrating immune cells was not significantly correlated with disease-free survival and overall survival.

Conclusions

PD-L1 expression in tumor cells and tumor infiltrating immune cells is not only an indicator for immunotherapy, but also significantly related with age, differentiation, stage, metastasis and disease free survival.

The Clinicopathologic and Prognostic Significance of Programmed Cell Death Ligand 1 (PD-L1) Expression in Patients With Prostate Cancer: A Systematic Review and Meta-Analysis

Background: Programmed cell death ligand 1 (PD-L1) expression has been shown to correlate with poor prognosis in diverse human cancers. However, limited data exist on the prognostic and clinicopathologic significance of PD-L1 expression in prostate cancers (PCa), and the curative effect of anti-PD-1/PD-L1 therapy remains controversial. In this systematic review and meta-analysis, we aimed to evaluate the prognostic and clinicopathologic value of PD-L1 in PCa. Methods: We performed a systematic literature search in the PubMed, Cochrane Library, EMBASE, Web of Science, and SCOPUS databases up to July 21st, 2018. Pooled prevalence of PD-L1 in PCa was calculated using Freeman-Tukey double arcsine transformation by R software version 3.5.0. The data from the studies were examined by a meta-analysis using Review Manager software 5.3 to calculate pooled hazard ratios (HRs) and pooled odds ratios (ORs) with 95% confidence intervals (CIs) to estimate the prognostic and clinicopathologic value of PD-L1 in PCa. Heterogeneity was tested by the Chi-squared test and I ² statistic. Results: Five studies with 2,272 patients were included in this meta-analysis. The pooled prevalence of PD-L1 in PCa was 35% (95% CI 0.32 to 0.37). Both PD-L1 expression (HR = 1.78; 95% CI 1.39 to 2.27; p < 0.00001) and PD-L1 DNA methylation (HR = 2.23; 95% CI 1.51 to 3.29; p < 0.0001) were significantly associated with poor biochemical recurrence-free survival (BCR-FS). PD-L1 tended to have high expression levels in high Gleason score cases (OR = 1.54; 95% CI, 1.17 to 2.03; P = 0.002) and androgen receptor-positive cases (OR = 2.42, 95% CI 1.31 to 4.50; P = 0.005). However, PD-L1 had relatively weak correlation with age, pathologic stage, lymph node metastasis and preoperative PSA level. Conclusions: This meta-analysis confirms the negative prognostic significance of PD-L1 expression and mPD-L1 in PCa patients. Additionally, PD-L1 has a statistically significant correlation with Gleason score and androgen receptor status, while the correlations with age, pathologic stage, lymph node metastasis, and preoperative PSA level were not statistically significant. However, the number of included studies is too small to make the conclusions more convincing, so more retrospective large-cohort studies are expected for the further confirmation of these findings.

Integrative analysis of PD-L1 DNA status, mRNA status and protein status, and their clinicopathological correlation, in diffuse large B-cell lymphoma

AIMS

The protein expression of programmed death-ligand 1 (PD-L1) has been recognised as being a biomarker for poor prognosis in diffuse large B-cell lymphoma (DLBCL). The aims of this study were to determine PD-L1 DNA status and mRNA status, and to explore whether they contribute to protein expression and their clinicopathological correlation in DLBCL.

METHODS AND RESULTS

In this study, we used fluorescence in-situ hybridisation, RNA in-situ hybridisation and immunohistochemistry to determine PD-L1 status at three different levels in 287 DLBCL samples with follow-up. Their correlation and clinical pathological relevance were also analysed. Our results showed that 1.7% (3/175) of patients had PD-L1 DNA amplification, 19.9% (57/287) had high PD-L1 mRNA expression, and 11.8% (34/287) had high PD-L1 protein expression. Both mRNA and protein expression of PD-L1 were significantly higher in non-germinal centre B-cell-like (GCB) DLBCL than in GCB DLBCL (P < 0.05). In addition, the patients with high PD-L1 mRNA or high PD-L1 protein expression but no PD-L1 DNA amplification had significantly poorer overall survival (OS) than those with low PD-L1 expression (P < 0.05). Furthermore, we found that PD-L1 mRNA and PD-L1 protein expression were highly correlated (P = 0.012), which was observed in all three samples with DNA amplification.

CONCLUSIONS

PD-L1 DNA amplification is a rare event, PD-L1 mRNA is the main contributor to the high PD-L1 protein expression, and the latter two will serve as important biomarkers for predicting the prognosis of DLBCL patients and selecting them for immunotherapy.

Human leukocyte antigen class II expression is a good prognostic factor in adult T-cell leukemia/lymphoma

Attenuated human leukocyte antigen (HLA) class I expression is implicated as a major immune escape mechanism in several types of tumor. We previously reported that HLA class I/β2 microglobulin and programmed death ligand-1 expression are prognostic factors in adult T-cell leukemia/lymphoma. A recent report suggested that HLA class II expression is also an important prognostic factor for the clinical outcome of programmed death-1 blockade therapy in recurrent/refractory Hodgkin lymphoma. This prompted us to evaluate HLA class II expression in adult T-cell leukemia/lymphoma and to compare the findings with the patients’ clinicopathological features. Of the 132 biopsy specimens examined from newly diagnosed patients, lymphoma cells were positive for HLA class II expression in 44 patients (33.3%), whereas programmed death ligand-1 expression was observed on neoplastic cells from nine patients (6.9%) and on stromal cells in the tumor microenvironment in 83 cases (62.9%). HLA class II-positive cases showed a significantly better overall survival compared to the HLA class II-negative cases (P<0.0001). Patients positive for HLA class II and programmed death ligand-1 microenvironmental expression had significantly better prognosis than the other groups (P<0.0001). HLA class II-positive and HLA class II-negative groups also showed a significant difference in complete remission rate (P=0.0421), HLA class I/β2 microglobulin expression (P=0.0165), and the number of programmed death-1-positive tumor infiltrating cells (P=0.0020). HLA class II expression was a prognostic factor for overall survival both in univariate and multivariate analyses (P<0.0001 and P=0.0007, respectively). Our study reveals that HLA class II is a novel prognostic factor in adult T-cell leukemia/lymphoma.

PD-L1 expression enhancement by infiltrating macrophage-derived tumor necrosis factor-α leads to poor pancreatic cancer prognosis

Immunotherapy using anti‐PD‐1/PD‐L1 antibodies for several types of cancer has received considerable attention in recent decades. However, the molecular mechanism underlying PD‐L1 expression in pancreatic ductal adenocarcinoma (PDAC) cells has not been clearly elucidated. We investigated the clinical significance and regulatory mechanism of PD‐L1 expression in PDAC cells. Among the various cytokines tested, tumor necrosis factor (TNF)‐α upregulated PD‐L1 expression in PDAC cells through NF‐κB signaling. The induction of PD‐L1 expression was also caused by co‐culture with activated macrophages, and the upregulation was inhibited by neutralization with anti‐TNF‐α antibody after co‐culture with activated macrophages. PD‐L1 expression in PDAC cells was positively correlated with macrophage infiltration in tumor stroma of human PDAC tissues. In addition, survival analysis revealed that high PD‐L1 expression was significantly associated with poor prognosis in 235 PDAC patients and especially in patients harboring high CD8‐positive T‐cell infiltration. These findings indicate that tumor‐infiltrating macrophage‐derived TNF‐α could be a potential therapeutic target for PDAC.

Simultaneous presence of lung adenocarcinoma and malignant pleural mesothelioma: A case report

The co-presence of malignant pleural mesothelioma (MPM) and lung cancer is rare. We report a 70-year-old male with exposure to asbestos. Chest computed tomography revealed a right mediastinal mass combined with an enlarged ipsilateral lymph node and left pleural effusion. Transbronchial lung biopsy revealed lung adenocarcinoma. Thoracoscopic examination revealed multiple left pleural nodules, leading to the diagnosis of MPM. Despite aggressive anticancer drug therapy, he expired due to disease progression 2.5 years after diagnosis. Autopsy confirmed an epithelioid MPM in the left pleura. MPM comorbidity in patients diagnosed with lung cancer should be considered, especially in those exposed to asbestos.

PD-L1 expression in pancreatic adenosquamous carcinoma: PD-L1 expression is limited to the squamous component

AIM

We examined the programmed death-ligand 1 (PD-L1) expression in surgically resected pancreatic adenosquamous carcinoma (PASC) samples. Furthermore, the detection rate was also assessed using biopsy cases obtained from endoscopic ultrasound-guided fine needle aspiration (EUS-FNA).

METHODS

Fifteen cases of PASC (six resected and nine EUS-FNA biopsied) from the Kurume University Hospital between 2009 and 2016 were used for the evaluation of PD-L1 expression. As a control group, 34 cases of pancreatic ductal adenocarcinomas (PDACs) were selected. To compare　the positivity and intensity of PD-L1, two types of clones (SP263, E1L3N) were examined for immunostaining. Only the membrane expression of PD-L1 was regarded as positive. The PD-L1 expressions in the squamous cell carcinoma component (SCc), adenocarcinoma component (ACc), and immune cells were assessed separately. The ratio of PD-L1 expression was calculated by counting the positive tumor cells, and tumor proportion score (TPS) was applied (TPS; Null < 1%, low expression; 1 ≤ TPS ≤ 49% and high expression; ≥ 50%).

RESULTS

PD-L1 expression was observed in five surgical PASC samples (83%). This shows that SCc presented a high expression in these cases. However, the overall TPS indicated a low expression. In contrast, only one case (3%) was positive for PD-L1 in PDACs, and the TPS indicated a low expression. No differences in PD-L1 expression were observed between the two clones, SP263 and E1L3N. High PD-L1 expression in the EUS-FNA sample was found in only one case (11%).

DISCUSSION

Although assessment using the tumor cells of PASC samples obtained from EUS-FNA was difficult, this study suggests the selective expression of PD-L1 in the SCc of PASC. Furthermore, it was considered that immune checkpoint inhibitors could provide therapeutic effects selectively on the SCc for the entire range of TPSs, though the PD-L1 expression was low.

Orchestration of immune checkpoints in tumor immune contexture and their prognostic significance in esophageal squamous cell carcinoma

Introduction

Esophageal squamous cell carcinoma (ESCC) develops in a background of chronic inflammation; therefore, it is a promising candidate for treatment by immunotherapy. Although tumor immunity is critically involved in tumor growth and metastasis in ESCC, important gaps exist in our understanding of its immune microenvironment. This study aimed to investigate the expression and prognostic significance of immune checkpoint proteins in ESCC and the associated T-cell densities.

Materials and methods

We investigated the infiltration of CD8⁺ T cells and the expressions of immune checkpoint proteins (PD-1, TIGIT, PD-L1, and PD-L2) in 154 primary ESCC patients by immunohistochemistry. The correlation of immune checkpoint proteins' expression and clinical outcomes was determined by Kaplan-Meier test and multivariate Cox regression analysis.

Results

PD-L1 and PD-L2 expression were detected in 45.5 and 59.7% of the ESCC samples, respectively. The high densities of PD-1⁺ and TIGIT⁺ tumor-infiltrating lymphocytes (TILs) were expressed in 47.4 and 49.4% of the ESCC patients, respectively. The number of PD-1⁺ TILs was significantly positively correlated with CD8⁺ TILs (P<0.001). Cases displaying high PD-L1 expression exhibited consistently high CD8⁺ T-cell infiltration (P=0.0157). Increased numbers of PD-1⁺ and TIGIT⁺ TILs alone or both, as well as PD-L1 and PD-L2 expression alone or both, were significantly and associated with a shorter overall survival among these patients. The combined analysis of the expression of PD-1, TIGIT, PD-L1, and PD-L2 found that a group of patients with PD-1⁺/TIGIT⁺ TILs and PD-L1- and/or PD-L2-positive tumor cells had the worst prognosis in primary ESCC.

Conclusion

These immune profiles of checkpoint proteins expression should guide the selection of ESCC patients to receive suitable immunotherapies.

PD-L2 expression is correlated with the molecular and clinical features of glioma, and acts as an unfavorable prognostic factor

Background: Gliomas are aggressive tumors with various molecular and clinical characteristics and exhibit strongly resistance to radio-chemotherapy. Programmed cell death 1 ligand 2 (PD-L2) is a cell surface protein, which was reported in many cancers, modulating cancer-associated immune responses, while the role of PD-L2 in gliomas remained unclear. Herein, we aimed to investigate the biological behaviors and clinical prognostic values of PD-L2 in gliomas.

Methods: Totally, we enrolled RNA sequencing data of 325 glioma samples from Chinese Glioma Genome Atlas (CGGA) as training cohort and RNA expression data of 1032 samples from The Cancer Genome Atlas (TCGA) dataset as validation cohort in this research. Then, the clinical and molecular characteristics, and the prognostic value of PD-L2 were analyzed.

Results: We found that PD-L2 expression level was significantly upregulated in higher grade glioma and IDH wild-type glioma. Receiver Operating Characteristic (ROC) analysis revealed that PD-L2 was a potential indicator of mesenchymal subtype. PD-L2 exhibited tight relationship with immune response and immune-modulating process in glioma. Moreover, PD-L2 expression level could predict unfavorable prognoses of patients independent of age, grade, IDH status and 1p/19q status.

Conclusions: Our study revealed that PD-L2 was closely related with inflammation and immune response. Patients with lower PD-L2 expression level tended to experience improved survival. Targeting PD-L2 may become a valuable approach for the treatment of gliomas in clinical practice.

High PD-L1 expression in the tumour cells did not correlate with poor prognosis of patients suffering for oral squamous cells carcinoma: A meta-analysis of the literature

OBJECTIVES

Oral cancer represents one of the most common malignancies in humans. Its prognosis is still poor, despite the most recent improvements in therapies. An increasing attention is placed on the role of programmed death ligand 1 (PD-L1) in the tumour immunity and its potential function as a marker for tumour prognosis. Whether PD-L1 expression is a prognostic factor for the poor outcomes in oral squamous cell carcinoma is still controversial. This study aimed to investigate, through a meta-analysis, a potential correlation between PD-L1 expression and the prognostic outcomes in patients with oral squamous cell carcinoma.

MATERIALS AND METHODS

The studies were identified by searching PubMed, SCOPUS, Web of Science and were assessed by two of the authors. After the selection process, 11 articles met eligibility criteria and were included in the meta-analysis. Quality assessment of studies was performed according to the REMARK guidelines, and the risk of biases across studies was investigated through Q and I² tests. Meta-analysis was performed to investigate the association between the PD-L1 expression either overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), gender and lymph node metastasis.

RESULTS

A total of 1060 patients were analysed in the 11 studies included in the meta-analysis. Pooled analysis revealed that the expression of PD-L1 did not correlate with poor OS (HR, 0.60; 95% CI: [0.33, 1.10]; P = 0.10), DFS (HR, 0.62; 95% CI: [0.21, 1.88]; P = 0.40), DSS (HR, 2.05; 95% CI: [0.53, 7.86]; P = 0.29 and lymph node metastasis (HR, 1.15; 95% CI: [0.74, 1.81]; P = 0.53). Furthermore, results of the meta-analysis showed that high expression of PD-L1 is two times more frequent in female patients (OR, 0.5; 95% CI: [0.36, 0.69]; P < 0.0001) compared to males. For all the three outcomes analysed, a high rate of heterogeneity was detected (I²  > 50%).

DISCUSSION

High PD-L1 expression did not correlate with poor prognosis of patients suffering for oral squamous cell carcinoma. Studies published on the topic showed a significant variation in results, limiting the use of PD-L1 expression by immunohistochemistry as prognostic biomarker in clinical practice.

Immune cells inhibit the tumor metastasis in the 4D cellular lung model by reducing the number of live circulating tumor cells

The immune system and tumor microenvironment play a decisive role in tumor progression. We developed a novel model to better understand tumor progression and interaction with immune cells and the cellular components. We grew 393 P non-metastatic and 344SQ metastatic murine cells in an acellular metastatic lung cancer model, where both cell lines formed circulating tumor cells (CTC) and metastatic lesions. When the CTC from this model were placed in the tail vein of nu/nu mice, both cell lines formed metastatic lesions. However, in syngeneic immune-competent mice, the CTC from the non-metastatic cell line did not metastasize while the CTC from the metastatic cell line metastasized. When we placed the activated immune cells in the cellular lung model, it decreased CTC and metastatic lesion formation for the non-metastatic cell line while it had no impact on metastatic cell line. The metastatic cell line had a significant increase in expression of programmed death-ligand 1 (PDL-1) compared to the non-metastatic cell line in the model. Overall, the immune cells showed an impact on viability of CTC for cell lines with a decreased expression of PDL-1 that leads to decreased metastatic lesion formation. Further studies are needed to understand the subtype of immune cells and mechanism of decreased CTC viability and metastasis inhibition.

Expression of programmed death ligand 1 and 2 in adrenocortical cancer tissues: An exploratory study

BACKGROUND

Inhibition of the interaction of programmed death 1 with programmed death ligand 1 and 2 has been used successfully for treatment of multiple advanced cancers, but expression has not been studied in adrenocortical carcinoma. In this study, we investigated programmed death ligand 1 and 2 expression in adrenocortical carcinoma to determine the potential usefulness of checkpoint inhibitors in these malignant neoplasms.

METHODS

A total of 56 tissue samples from patients with adrenocortical carcinoma (34) and benign adrenal tissues (22) were identified. Immunohistochemistry was performed for programmed death ligand 1, programmed death ligand 2, and CD8 and scored for membranous staining on adrenal and stromal tissue according to the immunoreactive score and absolute percentage, respectively. Descriptive statistics, a Mann-Whitney U test, and Fisher exact tests were calculated.

RESULTS

In total, 15 adrenocortical carcinoma (44%) stained positive for programmed death ligand 2 and 1 adrenocortical carcinoma for programmed death ligand 1 (P = .03). Adrenocortical carcinoma samples were more likely to express programmed death ligand 2 on tumor cells or in stromal tissues than benign samples (OR = 2.3, P = .03). There was no relationship between programmed death ligand 2 and CD8 expression (P = .08). There were also no relationships between programmed death ligand 2 or CD8 expression and tumor characteristics.

CONCLUSION

Programmed death ligand 2, but not programmed death ligand 1, is expressed commonly in adrenocortical carcinoma samples. The utility of certain checkpoint inhibitors should, therefore, be evaluated in further studies.

MERTK inhibition alters the PD-1 axis and promotes anti-leukemia immunity

MERTK is ectopically expressed and promotes survival in acute lymphoblastic leukemia (ALL) cells and is thus a potential therapeutic target. Here we demonstrate both direct therapeutic effects of MERTK inhibition on leukemia cells and induction of anti-leukemia immunity via suppression of the coinhibitory PD-1 axis. A MERTK-selective tyrosine kinase inhibitor, MRX-2843, mediated therapeutic anti-leukemia effects in immunocompromised mice bearing a MERTK-expressing human leukemia xenograft. In addition, inhibition of host MERTK by genetic deletion (Mertk-/- mice) or treatment with MRX-2843 significantly decreased tumor burden and prolonged survival in immune-competent mice inoculated with a MERTK-negative ALL, suggesting immune-mediated therapeutic activity. In this context, MERTK inhibition led to significant decreases in expression of the coinhibitory ligands PD-L1 and PD-L2 on CD11b+ monocytes/macrophages in the leukemia microenvironment. Furthermore, although T cells do not express MERTK, inhibition of MERTK indirectly decreased PD-1 expression on CD4+ and CD8+ T cells and decreased the incidence of splenic FOXP3+ Tregs at sites of leukemic infiltration, leading to increased T cell activation. These data demonstrate direct and immune-mediated therapeutic activities in response to MERTK inhibition in ALL models and provide validation of a translational agent targeting MERTK for modulation of tumor immunity.

PD-1 Haplotype Combinations and Susceptibility of Patients to Squamous Cell Carcinomas of Head and Neck

INTRODUCTION

Head and neck squamous cell carcinomas (HNSCCs) are the most common cancers of head and neck and the sixth most common malignancy worldwide. Programmed cell death 1 (PD-1) is an immune inhibitory molecule which through interaction with its ligands recruits protein phosphatase resulting in immune response inhibition. Expression of PD-1 ligands on tumor cells is considered as one of the crucial immune evasion mechanisms. This study aimed to investigate the association of PD-1 gene polymorphisms at positions PD1.3 (rs11568821), PD1.5 (rs2227981) and PD1.9 (rs2227982) with susceptibility to HNSCCs.

SUBJECTS AND METHODS

150 patients pathologically confirmed to suffer from HNSCCs and 150 age-sex matched healthy controls were recruited in this study. Genomic DNA was extracted from white blood cells of all participants. Restricted fragment length polymorphisms (RFLP)-PCR was performed using site specific primers to determine the genotypes in each position.

RESULTS

Statistical analyses indicated no significant differences in the frequencies of genotypes, alleles as well as haplotypes between patients and controls (P > 0.05), however, haplotype combination differed significantly between two groups. GCC/GCT, GCC/GCC and GCT/GCC were higher in the HNSCC patients than the control group (P < 0.05). On the other hand, in the controls, GCT/GCT, GCT/ACC, GCT/ACT and ACC/GCT were more frequent. No significant association was found with various HNSCC clinicopathological characteristics.

DISCUSSION

Our results suggested that although PD-1 gene polymorphisms at three investigated positions are not solely associated with susceptibility to HNSCCs, haplotype combinations emerged from these three loci may render susceptibility.

Prognostic significance of interferon regulating factor 4 in esophageal squamous cell carcinoma

BACKGROUND

Aberrant expression of interferon regulatory factor 4 (IRF4) has been reported in several hematologic malignancies. However, the prognostic significance of IRF4 expression in esophageal squamous cell carcinoma (ESCC) remains unknown.

METHODS

IRF4 protein expression in ESCC tumor specimens was determined immunohistochemically. The correlation of IRF4 expression with clinico-pathological features was assessed from a cohort of 100 patients with primary ESCC. Kaplan-Meier and Cox proportional regression analyses were used to evaluate the association between IRF4 expression and patient survival.

RESULTS

A Kaplan-Meier analysis indicated that patients with high IRF4 expression had a significantly longer overall survival rate than those with low IRF4 expression (p = 0.0006). Furthermore, multi-variate analyses revealed that IRF4 protein expression is an independent prognostic indicator for ESCC patients.

CONCLUSION

Our results suggest that increased IRF4 protein expression correlates with improved outcome in ESCC. IRF4 may therefore represent a promising prognostic biomarker and potential immuno-therapeutic target for patients with ESCC.

Expression of B7 Homolog 1 (B7H1) Is Associated with Clinicopathologic Features in Urothelial Bladder Cancer

BACKGROUND B7 homolog 1 (B7H1) plays an important role in regulating tumor immunity. The purpose of this study was to probe the relationship between B7H1 expression and clinical outcomes in urothelial bladder cancer. MATERIAL AND METHODS We investigated 110 urothelial bladder cancer cases. The expressions of B7H1 in tumors were analyzed by immunohistochemistry and RT-PCR. The correlation between B7H1 expression and survival rate was analyzed by log-rank test. RESULTS B7H1 expression was significantly increased in cancerous tissues compared to normal tissues (p<0.05). B7H1 expression was not associated with sex, age, diameter, or the combination of these factors (p>0.05). The positive expression of B7-H1 was positively correlated with grade, stage, recurrence, and metastasis (p<0.05). The RT-PCR results were consistent with the immunohistochemistry outcomes. Furthermore, the expression of B7H1 in tumors was highly correlated with the survival rate (p<0.05). CONCLUSIONS Expression of B7H1 is correlated with clinicopathologic features in bladder cancer. Up-regulation of B7H1 can result in progression and recurrence of urothelial bladder cancer.

Frontiers and Opportunities: Highlights of the 2nd Annual Conference of the Chinese Antibody Society

Background

Programmed cell death 1 (PD-1) is an inhibitory immune checkpoint expressed on activatedT cells. Upon the formation of T cell receptor (TCR)-pMHC complexes, concomitant PD-1 ligation to its ligands programmed death-ligand 1 (PD-L1) or programmed death-ligand 2 (PD-L2) downregulates TCR signaling and effector function. Here we describe the preclinical characterization of Sintilimab, a fully human IgG4 antibody that potently blocks PD-1 interactions with PD-L1 and PD-L2.

Methods

The binding affinity and blockade function were detected by using surface plasmon resonance (SPR), Enzyme-linked immunosorbent assay (ELISA) and flow cytometry. The biology function properties were measured with luciferase assay and mixed lymphocyte reaction assay. In vivo anti-tumor function and preclinical pharmacokinetic (PK) were identified with human PD-1 transgenic mice and non-human primates separately.

Results

Sintilimab can specifically and strongly bind to human PD-1 (hPD-1) and cynomolgus PD-1 and the affinity of Sintilimab to human PD-1 was measured at 0.3 nm via surface SPR, and displayed slow dissociation kinetics. Sintilimab can block the interaction of PD-1 to PD-L1 and PD-L2 and induce high secretion levels of interferon (IFN)-γ and interleukin (IL)-2 in primary T cell assays. In humanized hPD-1 knock-in mouse models, Sintilimab showed potent anti-tumor activity and increased tumor-infiltrating CD8/CD4 T cell and CD8/ Treg ratios. Preclinical experimentation in non-human primates following a single intravenous infusion of Sintilimab at 1, 6 and 30 mg/kg presented with no signs of drug-related toxicity, and showed typical PK characteristics of an IgG antibody.

Conclusions

Sintilimab has desirable preclinical attributes that supports its clinical development for cancer treatment.

A nomogram-based immunoprofile predicts overall survival for previously untreated patients with esophageal squamous cell carcinoma after esophagectomy

Background

Immunoscore, as a prognostic tool defined to quantify in situ immune cell infiltrates, appears to be superior to the TNM staging system. In esophageal squamous cell carcinoma (ESCC), no immunoscore has been established; however, in situ tumor immunology is recognized as highly important. Our study aimed to construct a comprehensive immunoprofile for ESCC.

Methods

The infiltration of four immune cell types (CD8+/CD4+/Foxp3+/CD33+ cells), the expression of both inhibitory (PD-1/PD-L1/Tim-3/LAG-3) and stimulatory checkpoints (OX-40/ICOS), and IDO1 were evaluated by IHC staining and multi-color immunofluorescence in two independent cohorts (95 patients in the primary cohort and 55 patients in the validation cohort). The association with patients’ overall survival was analyzed by the Kaplan-Meier method and the Cox model. Nomogram-based immunoprofile was established using the independent prognostic variables. To determine its predictive accuracy and discriminatory capacity, the C-index and calibration curve were calculated.

Results

Significant correlation of PD-L1 expression in tumor cells with PD-1+ T cell infiltration was found (P = 0.035), indicating the activation of the inhibitory PD-1/PD-L1 pathway in ESCC cases. More PD-L1+ ICs, Tim-3+ ICs and LAG-3+ ICs were found in the CD8-rich tumor microenvironment, which is in accordance with the feedback nature of immune system. After adjustment by TNM stage, four immune variables including the infiltration of CD8+/Foxp3+/CD33+ cells and the PD-L1 expression by tumor cells were selected to construct a prognostic nomogram. The calibration curves showed good accuracy of the nomogram for survival prediction. To overcome the complexity of applying a nomogram in a clinical setting, a simple immunoprofile was then established according to the points of each factor from the nomogram. Our immunoprofile model could separate same-stage patients into different risk subgroups, and showed superior accuracy for survival prediction than the TNM staging system based on the C-index calculation and ROC analysis.

Conclusions

Our nomogram-based immunoprofile can provide more accurate prognosis prediction and is an important complement to the TNM staging system for operable ESCC patients.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0418-7) contains supplementary material, which is available to authorized users.

Strategies for Predicting Response to Checkpoint Inhibitors

PURPOSE OF REVIEW

Despite the clinical successes of immune checkpoint blockade across multiple tumor types, many patients do not respond to these therapies or become resistant after an initial response. This underscores the need to improve our understanding of the molecular determinants of response to guide more personalized and rational utilization of these therapies. Here, we describe available biomarkers of checkpoint blockade activity by classifying them into four major categories: tumor-intrinsic, immune microenvironmental, host-related, and dynamic factors.

RECENT FINDINGS

The clinical experience accumulated thus far with checkpoint blockade now offers the opportunity to comprehensively study the molecular and immune features associated with response. This is yielding a growing set of biomarkers whose integration will be key to more accurately predict clinical outcome. We propose a model for systematic assessment of available baseline and dynamic biomarkers in relationship with patients' outcomes. This will improve our understanding of the tumor-immune interactions and dynamics that predict a clinical response and will provide key information to develop more personalized and effective treatment strategies.

The intracellular signalosome of PD-L1 in cancer cells

Programmed cell death-1 ligand-1 (PD-L1) overexpression in cancer cells accelerates tumor progression. PD-L1 possesses two main pro-oncogenic functions. First, PD-L1 is a strong immunosuppressive molecule that inactivates tumor-specific T cells by binding to the inhibitory receptor PD-1. Second, PD-L1 function relies on the delivery of intrinsic intracellular signals that enhance cancer cell survival, regulate stress responses and confer resistance toward pro-apoptotic stimuli, such as interferons. Here, we review the current knowledge on intracellular signal transduction pathways regulated by PD-L1, describe its associated signalosome and discuss potential combinations of targeted therapies against the signalosome with PD-L1/PD-1 blockade therapies.

On the Road to Immunotherapy-Prospects for Treating Head and Neck Cancers With Checkpoint Inhibitor Antibodies

Head and neck cancers (HNC) represent a heterogeneous cluster of aggressive malignancies that account for 3% of all cancer cases in the UK. HNC is increasing in frequency particularly in the developing world, which is related to changes in risk factors. Unfortunately, the mortality rate is high, which is chiefly attributed to late diagnosis at stages where traditional treatments fail. Cancer immunotherapy has achieved great successes in anti-tumor therapy. Checkpoint inhibitor (CI) antibodies enhance anti-tumor activity by blocking inhibitory receptors to drive tumor-specific T and NK cell effector responses. Since their introduction in 2011, CI antibodies have been approved for many cancer types including HNC. Here, we examine the development of CI therapies and look forward to future developments for treatment of HNC with CI therapies.

PD-1/PD-L1 immune checkpoint: Potential target for cancer therapy

Recent studies show that cancer cells are sometimes able to evade the host immunity in the tumor microenvironment. Cancer cells can express high levels of immune inhibitory signaling proteins. One of the most critical checkpoint pathways in this system is a tumor-induced immune suppression (immune checkpoint) mediated by the programmed cell death protein 1 (PD-1) and its ligand, programmed death ligand 1 (PD-L1). PD-1 is highly expressed by activated T cells, B cells, dendritic cells, and natural killer cells, whereas PD-L1 is expressed on several types of tumor cells. Many studies have shown that blocking the interaction between PD-1 and PD-L1 enhances the T-cell response and mediates antitumor activity. In this review, we highlight a brief overview of the molecular and biochemical events that are regulated by the PD-1 and PD-L1 interaction in various cancers.

Frontiers and Opportunities: Highlights of the 2nd Annual Conference of the Chinese Antibody Society

The Chinese Antibody Society (CAS) convened the second annual conference in Cambridge, MA, USA on 29 April 2018. More than 600 members from around the world attended the meeting. Invited speakers discussed the latest advancements in therapeutic antibodies with an emphasis on the progress made in China. The meeting covered a vast variety of topics including the current status of therapeutic antibodies, the progress of immuno-oncology, and biosimilars in China. The conference presentations also included the development of several novel antibodies such as antibodies related to weight loss, T-cell receptor-mimicking antibodies that target intracellular antigens, and tumor-targeting antibodies that utilize both innate and adaptive immune pathways. At the meeting, the CAS announced the launch of its official journal-Antibody Therapeutics-in collaboration with Oxford University Press. The conference was concluded by a panel discussion on how to bring a therapeutic drug developed in China to the USA for clinical trials.

Indoleamine 2, 3-dioxygenase and B7-H1 expressions as prognostic and follow-up markers in human pancreatic carcinoma

This study was to test hypotheses that indoleamine 2, 3-dioxygenase and B7-H1 expressions can be used as prognostic markers in human pancreatic carcinoma (PC). Ninety-five patients were recruited who had undergone radical surgical resection for PC. IDO and B7-H1 expressions in PC tissue specimens were evaluated by immunohistochemistry (IHC) techniques. The clinical and pathological features of these specimens were analyzed. IDO positive, B7-H1 positive, and combined IDO/B7-H1 positive tumors exhibited significant correlations with lymphocytic infiltration, perineural invasion, TNM status, and pathologic grade (p < .05), which tended to show strong correlations with malignant progression of PC. Also, IDO correlated with diabetes mellitus (DM) and HAD scale and B7-H1 correlated with smoke (p < .05). In addition, the correlation analysis indicated that IDO had a positive correlation with B7-H1 (p < .05). Moreover, the results showed that a combination of IDO and B7-H1 expressions could serve as independent prognostic marker after adjusting by Cox proportional hazards regression models (p < .05). IDO and B7-H1 expressions were observed in patient with PC tissues and are important markers for PC malignant progression. A combination of IDO and B7-H1 expression can be served as an independent prognostic marker for PC.

Prognostic impact of programmed cell death ligand 1 expression on long-term oncologic outcomes in colorectal cancer

The present study evaluated the association between programmed cell death ligand-1 (PD-L1) expression and long-term oncologic outcomes in colorectal cancer (CRC). PD-L1 expression was evaluated using immunohistochemistry in 175 patients who underwent surgical resection for CRC between September 1999 and August 2004. Patients were grouped according to PD-L1 expression, with 82 (46.9%) and 93 (53.1%) in the low and high PD-L1 expression groups, respectively. The overall survival (OS) and disease-free survival (DFS) rates were significantly better in the high expression group compared with in the low expression group (OS: 48.2 vs. 32.9%, P=0.047; DFS: 43.3 vs. 32.9%, P=0.021). According to the Tumor-Node-Metastasis stage subgroups, the OS rates in the low and high expression groups, respectively, were 66.7 and 60.0% in stage I (P=0.715), 51.8 and 46.7% in stage II (P=0.789), 19.6 and 51.1% in stage III (P=0.011) and 9.1 and 0% in stage IV (P=0.005). The DFS rates in the low and high expression groups, respectively, were 66.7 and 60.0% in stage I (P=0.715), 51.8 and 46.7% in stage II (P=0.857), 19.6 and 38.3% in stage III (P=0.006) and 9.1 and 0% in stage IV (P=0.700). The systemic recurrence rate was significantly higher in the low expression group compared with in the high expression group (42.7 vs. 12.9%, respectively, P=0.030). Low PD-L1 expression was significantly associated with tumor relapse and poor prognosis in stage III CRC.

Biomarkers of response to immune checkpoint blockade in cancer treatment

Immune checkpoint inhibitors (ICPis) are emerging as the new corner stone of cancer treatment due to their ability to produce durable responses in patients with various cancers. But, objective responses to ICPis vary among each type of cancer. Further, treatment with ICPis is often associated with risk of developing immune-related adverse event, which are potentially life-threatening if untreated, indicating a need for patient selection. However, given the complexity of the tumor microenvironment and the dynamic interaction between tumor and immune cells, development of robust biomarkers to predict patients who are likely to respond to treatment with ICPis remains a challenge. In this review we present an overview of the immune monitoring strategies that are currently in use to enable appropriate patient selection.

Advances in immuno-oncology biomarkers for gastroesophageal cancer: Programmed death ligand 1, microsatellite instability, and beyond

Blockade of the programmed death ligand 1 (PD-L1) and programmed cell death 1 (PD-1) receptor axis represents an effective form of cancer immunotherapy. Preclinical evidence initially suggested that gastric and gastroesophageal junction (GEJ) cancers are potentially immunotherapy-sensitive tumors. Early phase clinical trials have demonstrated promising antitumor activity with PD-1/PD-L1 blockade in advanced or metastatic gastric/GEJ cancer. Microsatellite instability (MSI) and PD-L1 expression have been shown to predict higher response to PD-1 inhibitors as highlighted by the recent approvals of pembrolizumab in treatment-refractory solid tumors with MSI status and the third-line or greater treatment of PD-L1 positive advanced gastric/GEJ cancers. However, predictive and prognostic biomarkers remain an ongoing need. In this review, we detail the preclinical evidence and early tissue biomarker analyses illustrating potential predictive biomarkers to PD-1/PD-L1 blockade in gastric/GEJ cancer. We also review the clinical development of PD-1/PD-L1 inhibitors in gastric/GEJ cancer and highlight several areas in need of future investigation in order to optimize the efficacy of PD-1/PD-L1 blockade in gastric/GEJ cancer.

Prognostic significance of programmed death ligand-1 immunohistochemical expression in esophageal cancer: A meta-analysis of the literature

BACKGROUND

It is thought that expression of programmed death ligand-1 (PD-L1) in esophageal cancer (EC) might compromise patient survival. However, the association between PD-L1 expression and survival of patients with EC remains controversial.

METHODS

A meta-analysis combining eligible published studies was performed to evaluate the effect of PD-L1 expression in tumor cells detected by immunohistochemistry (IHC) on overall survival (OS) and disease-free survival (DFS) in patients with EC, using pooled hazard ratio (HR) with its 95% confidence interval (CI).

RESULTS

The pooled HR for 19 eligible studies (18 publications, n = 3306) suggested that PD-L1 overexpression had an unfavorable impact on OS (HR = 1.42, 95% CI: 1.09-1.86). No significant effect of PD-L1 overexpression on DFS was observed, and the combined HR was 1.08 (95% CI: 0.76-1.53) for 12 eligible studies (11 publications, n = 2260).

CONCLUSION

PD-L1 expression in tumor cells detected by IHC was associated with worse OS in EC. However, the prognostic value of PD-L1 expression in tumor cells on OS in EC still needs further large prospective trials to be clarified.

Immunohistochemical Analysis of Foxp3+, CD4+, CD8+ Cell Infiltrates and PD-L1 in Oral Squamous Cell Carcinoma

The immunoexpression of the PD-L1 and the number of immune infiltrating cells have been shown to be a significant prognostic factors in various human cancers. Immunohistochemical method was used to examine the immunoexpression of PD-L1 and number of Foxp3+, CD4+, CD8+ cells in 78 cases of oral squamous cell carcinomas (OSCCs): with better prognosis - OSCCBP (n = 37), and with poorer prognosis - OSCCPP (n = 41), and 18 cases of normal mucosa as a control. The immunoexpression of PD-L1 and the mean number of Foxp3+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. The mean number of CD4+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. CD8+ cells were significantly more numerous in OSCCBP group in comparison to OSCCPP and control group. In both OSCCPP and OSCCBP groups there were positive significant correlations between number of Foxp3+ and CD4+ cells. We found positive correlations between the immunoexpression of PD-L1 and numbers of Foxp3+ cells, and negative correlation between the immunoexpression of PD-L1 and numbers of CD8+ cells in both OSCCPP and OSCCBP groups. We found also significant positive correlation between immunoexpression of PD-L1 and the number of CD4+ cells in OSCCPP group. In conclusion, our findings support the hypothesis of involvement of Tregs and PD-L1 in OSCC development and progression.

Clinical relevance of PD-L1 and PD-L2 overexpression in patients with esophageal squamous cell carcinoma

Background

Even with the advance of diagnosis and the treatment, the 5-year survival rate for esophageal cancer patients is still poor. The checkpoint protein inhibition provides another choice to improve the survival. The expression of the programmed death ligand-1 (PD-L1) was reported but the clinical relevance remained inconsistent in esophageal cancer. Besides, there were few references about the other ligand, programed death ligand-2 (PD-L2). In this study, we evaluated the expressions of PD-L1 and PD-L2 in patients with esophageal squamous cell carcinoma (ESCC) and assessed their clinical relevance.

Methods

From 1996 to 2011, 150 patients undergone complete surgical resection for ESCC were enrolled. Clinical data were recorded. Expression of PD-L1 and PD-L2 on cytoplasm in paraffin embedded tumor samples were analyzed by immunohistochemistry staining and scored with a semi-quantitative method.

Results

Of the patients, 96 (64.0%) patients had PD-L1 overexpression and 63 (42.0%) had PD-L2 overexpression. There was a correlation between the expression of PD-L1 and PD-L2 (P<0.001). Patients without overexpression of PD-L1, pathological T1-2 and N0 status, pathological stage I-II and no post-operative adjuvant treatment had a better disease free survival (DFS). In multivariate analysis, PD-L1 expression and pathological stage were the independent prognostic factors for DFS. The expression of PD-L2 did not influence the DFS. Although not statistically significant, patients without overexpression of PD-L1 and PD-L2 seem to have a better overall survival (OS).

Conclusions

The overexpression of PD-L1 on cytoplasm, not PD-L2, is an independent prognostic factor for DFS in patients with ESCC undergone esophagectomy. However, there is a trend which suggested that patients without overexpression of PD-L1 and PD-L2 had a better OS.

PD-L1 Expression On tumor Cells Was Associated With Unfavorable Prognosis In Esophageal Squamous Cell Carcinoma

Background: Evidence about the association between programmed cell death ligand 1 (PD-L1) expression and prognosis of esophageal squamous cell carcinoma (ESCC) were limited and controversial. Thus, the present study aims to investigate the prognostic value of tumor immune microenvironment (TIM) based on PD-L1 expression and CD8+ T cell infiltration in ESCC tissues.

Methods: From September 2008 to March 2010, a total of 146 ESCC patients received radical esophagectomy were retrospectively analyzed in our present study. PD-L1 expression and CD8+ T cell infiltration were evaluated through immunohistochemistry. The clinicopathological characteristics and survival were analyzed.

Results: There were 111 male and 35 female. The median age was 59.1 years (37-78 years). The positive rate of PD-L1 expression was 61.7%. The rate of high CD8+ T cell infiltration was 33%. No significant differences were found between clinicopathological features and PD-L1 expression or CD8+ T cell infiltration. PD-L1 expression was significantly associated with poor overall survival (P=0.010). However, CD8+ T cell infiltration was not a prognostic risk factor. Type of TIM was significantly associated with the prognosis of ESCC patients (P=0.021).

Conclusions: PD-L1 expression was an independent risk factor for the prognosis of ESCC patients. Immunotherapy may achieve promising outcomes in ESCC patients with type I TIM.

Immunotherapy in non-small-cell lung cancer: a bridge between research and clinical practice

Lung cancer has been historically considered a poorly immunogenic disease because of the few evidence of immune responses in affected patients and the limited efficacy of immunomodulating strategies. Recent understanding of the molecular mechanisms leading to cancer immune evasion has allowed the development of a new class of drugs called immune checkpoint inhibitors, which reactivate host responses with outstanding clinical benefits in a portion of patients with non-small-cell lung cancer. In this review, we briefly summarize the basis of immunogenicity and immune escape of cancer, with specific focus on non-small-cell lung cancer, mechanisms underlying immune checkpoint inhibitors efficacy and the most updated results on potential biomarkers, with the final aim of defining current unmet needs of immunotherapy in clinical practice.

What Will We Expect From Novel Therapies to Esophageal and Gastric Malignancies?

Esophageal cancer and gastric cancer are aggressive diseases for which treatment approaches are facing a new era. Some molecular pathways, such as VEGF, EGFR, fibroblast growth factor receptor, PIK3CA, and PARP-1, have been studied, and novel targeted drugs are presumed to be developed in the near future. From The Cancer Genome Atlas report, 80% of Epstein-Barr virus tumors and 42% of tumors with microsatellite instability have PIK3CA mutations, suggesting that this pathway could be reevaluated as a possible target for new systemic treatment of gastric cancer. Notably, higher PARP-1 expression can be found in gastric cancer, which might be related to more advanced disease and worse prognosis. In addition, PD-L1 expression, high microsatellite instability, and mismatch repair deficiency can be found in gastric cancer, thus suggesting that immunotherapy may also play a role in those patients. We discuss trends related to the potential of novel therapies for patients with esophageal and gastric cancers in the near future.

Indoleamine 2,3-dioxygenase 1 and overall survival of patients diagnosed with esophageal cancer

BACKGROUND

Indoleamine 2,3-dioxygenase 1 (IDO1) is an enzyme with immunomodulatory properties that has emerged as a potential immunotherapeutic target in human cancer. However, the role, expression pattern, and relevance of IDO1 in esophageal cancer (EC) are poorly understood. Here, we utilize gene expression analysis of the cancer genome atlas (TCGA) and immunohistochemistry (IHC) to better understand the role and prognostic significance of IDO1 in EC.

RESULTS

High IDO1 mRNA levels were associated with worse overall survival (OS) in both esophageal squamous cell carcinoma (SCC) (P = 0.02) and adenocarcinoma (AC) (P = 0.036). High co-expression of IDO1 and programmed death ligand 1 (PD-L1) was associated with worse OS in SCC (P = 0.0031) and AC (P = 0.0186). IHC for IDO1 in SCC showed a significant correlation with PD-L1 (P < 0.0001) and CD3ε (P < 0.0001).

CONCLUSIONS

EC with high IDO1 and PD-L1 expression is significantly correlated with decreased patient survival, and may correlate with increased T-cells. These data suggest that simultaneous inhibition of IDO1 and PD-(L)1 may overcome important barriers to T-cell mediated immune rejection of EC.

MATERIALS AND METHODS

mRNA expression data from TCGA (SCC N = 87; AC N = 97). IHC in a second cohort of EC (N = 93) were stained for IDO1, PD-L1, and CD3ε, followed by light microscopic analysis.

Significance of PD-L1 expression in pulmonary metastases from head and neck squamous cell carcinoma

BACKGROUND

The mechanism by which tumors escape the immune system has been actively investigated and is partly explained by the programmed death-1 (PD-1) and its ligand (PD-L1) pathway. This study is aimed at clarifying the prognostic significance of PD-L1 expression in patients with surgically resected pulmonary metastases of head and neck squamous cell carcinoma (HNSCC).

PATIENTS AND METHODS

A retrospective review was conducted of 26 HNSCC patients who underwent complete resection of pulmonary metastases. PD-L1 expression in both the primary and metastatic tumors was evaluated using immunohistochemistry (anti-PD-L1 antibody, clone SP263). High PD-L1 expression was defined as ≥50% of tumor cells with positive staining. Survival and prognostic impacts following pulmonary metastasectomy were analyzed based on the PD-L1 expression level.

RESULTS

The patients included 23 men and 3 women, with a median age of 65 years. Six (23%) of the pulmonary metastatic cases showed high PD-L1 expression, while their corresponding primary lesions had low PD-L1 expression. The 5-year overall survival rate after pulmonary metastasectomy was 57.6% in all cases. The 5-year overall survival rates were 72.5% and 16.7% in the low and high PD-L1 groups, respectively (p < 0.001). Multivariate analysis demonstrated that high PD-L1 expression and older age (>65 years) correlated independently with a shorter overall survival (p < 0.001).

CONCLUSIONS

High PD-L1 expression in pulmonary metastases could be an independent predictor of poor outcome in HNSCC patients undergoing pulmonary metastasectomy. This is the first report evaluating the prognostic implication of PD-L1 expression in metastatic HNSCC.

Increased intraepithelial CD3+ T-lymphocytes and high PD-L1 expression on tumor cells are associated with a favorable prognosis in esophageal squamous cell carcinoma and allow prognostic immunogenic subgrouping

Esophageal squamous cell carcinoma (ESCC) is the most common esophageal cancer associated with poor prognosis and additional therapeutic strategies must be implemented to optimize ESCC treatment. Meanwhile, the important biologic role and potential prognostic and therapeutic implications of a tumors immunologic microenvironment (IM) have been recognized in various cancers.In order to investigate the contexture and the prognostic relevance of the IM in ESCC, we immunohistochemically evaluated the extent of overall/intraepithelial TILs (CD3+/CD8+) and of PD-1 / PD-L1 expression in a cohort of 125 therapy-naive ESCCs, additionally assessing PD-L1 copy number status via fluorescence in-situ hybridization.High intraepithelial CD3+ TILs (CD3ihigh) and high PD-L1 expression on tumor cells (PD-L1high) were each significantly associated with improved overall- (OS) (CD3+: p = 0.019; PD-L1: p = 0.028), disease specific- (DSS) (CD3+: p = 0.05; PD-L1: p = 0.006) and disease free survival (DFS) (CD3+: p = 0.009; PD-L1: p < 0.001). CD3ihigh- and PD-L1high cases were significantly associated with one another (p < 0.001). Subgrouping of ESCC revealed decreased OS (p = 0.031), DSS (p = 0.012) and DFS (p < 0.001) for CD3ilow/PD-L1low cancers.Our data not only associate CD3ihigh- and PD-L1high ESCC with a beneficial outcome, but also demonstrate PD-L1high- and CD3ihigh status to be closely intertwined. Furthermore, our study demarcates a prognostically unfavorable, "non-immunoreactive" CD3ilow / PD-L1low ESCC-subgroup, potentially forming the basis for an immune-based stratification of ESCC.

Use of the tumor-infiltrating CD8 to FOXP3 lymphocyte ratio in predicting treatment responses to combination therapy with pertuzumab, trastuzumab, and docetaxel for advanced HER2-positive breast cancer

Background

The trastuzumab, pertuzumab, and docetaxel (TPD) regimen is strongly recommended as a treatment option for first-line therapy for advanced human epidermal growth factor receptor (HER) 2-positive breast cancer. Monitoring the host microenvironments in cancer plays a significant role in predicting prognoses and curative effects. It is important to clarify the role of immune related gene expression in tumor-infiltrating lymphocytes in the tumor microenvironment. In this study, we evaluated the impact of chemotherapy with a TPD regimen, on immune micro environments in HER2-positive breast cancer using immune related proteins as indicators.

Methods

The subjects consisted of 30 patients who received the TPD regimen. The expression levels of estrogen receptor, progesterone receptor, Ki67, CD8, forkhead box protein (FOXP) 3, programmed death (PD) 1, programmed death ligand (PD-L) 1, CD163, phosphatase and tensin homolog and lymphocyte activation gene 3 were evaluated in biopsy specimens, by immunostaining.

Results

CD8⁺, CD8/FOXP3 ratio (CFR)^high and PD-L1⁻ group had significantly longer PFS than the CD8⁻, CFR^low and PDL1⁺ group (p = 0.045, log-rank) (p = 0.007, log-rank) (p = 0.040, log-rank), respectively. The CFR^high group had significantly better OS than the CFR^low group (p = 0.034, log-rank). In the univariate analysis, CD8⁺, CFR^high groups extended PFS significantly (p = 0.027, hazard ratio [HR] = 0.162) (p = 0.008, HR = 0.195), respectively. The receiver operating characteristic (ROC) analyses showed that the results for CFR [area under the curve (AUC): 0.708] were better than those for other factors (AUC: CD8 = 0.681, FOXP3 = 0.639, PD1 = 0.528, PD-L1 = 0.681).

Conclusions

This study shows with the TPD regimen, a high CFR leads to a high ORR and long PFS in HER2-positive breast cancer. CFR, therefore, may be one of the important prognostic factors for this disease.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1460-4) contains supplementary material, which is available to authorized users.

Immune checkpoint inhibitors in gastrointestinal malignancies

Gastrointestinal (GIT) tumors are extremely fatal and lethal tumors with limited therapeutic options. Antitumor immunity is new line of research in management of solid tumors. Immune check points are negative regulators of immune system and control the immune response. These checkpoints are exploited by cancer cells. Cancer cells causes early activation of checkpoints and suppress the immune response, and therefore have unchecked growth and metastasis of malignant cells. Immune checkpoint inhibitors (ICIs), downregulates these checkpoints and activate the proliferation of cytotoxic T cells which helps in lysis of tumor cells. ICIs have shown the promising results in management of melanoma, non-small cell lung cancer and renal cell carcinoma. Encouraged by their recent success in solid tumors many clinical trials are ongoing to evaluate their efficacy in GIT tumors. In this article we will try to explain rationale for use of ICIs in GIT tumors. We will summarize the ongoing research, preliminary results and future aspects of ICIs in GIT malignancies.

The concentration of programmed cell death-ligand 1 in the peripheral blood is a useful biomarker for esophageal squamous cell carcinoma

BACKGROUND

We determined the serum concentrations of Programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2) in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

Blood samples were collected from 85 patients with histologically proved ESCC. Serum levels of PD-1, PD-L1, and PD-L2 were measured using enzyme linked immunosorbent assays. Correlations between serum PD-1, PD-L1, and PD-L2 concentration and tumor depth, number of lymph node metastases, organ metastasis status, or disease stage were assessed and five-year survival rates according to clinicopathological characteristics were calculated.

RESULTS

The concentration of PD-1 was not differed according to tumor progression. On the other hand, the average concentration of PD-L1 in patients with T3/T4 disease was 15.6 (12.2-18.3) pg/mL (25-75%), and this was significantly higher than that in patients with Tis/T1/T2 disease (p = 0.020). Similarly, PD-L1 levels were significantly higher in patients with positive lymph nodes than in cases with negative lymph node involvement (p = 0.006) and were higher in patients with organ metastasis (p = 0.123) and in more advanced stage (p = 0.006). Similar tendency was observed regarding PD-L2 concentrations. PD-L2 concentration was higher in T3, T4 cases (p = 0.008), in LN positive cases (p = 0.032), and in more advanced stage (p = 0.024).

CONCLUSION

Our data showed that a concentration of PD-L1 in peripheral blood was high in advanced cancer and high concentration of PD-L1 predicted disease progression and also poor survival in patients with ESCC.