Expression of programmed death ligand 1 (PD-L1) is associated with poor prognosis in human breast cancer

A new perspective: Exploring future therapeutic strategies for cancer by understanding the dual role of B lymphocytes in tumor immunity

Our previous understanding of the role of B lymphocytes in tumor immunity is its antitumor effects. However, further evidence indicates B lymphocytes can also promote tumorigenesis by modulating immune responses. Therefore, the increasingly complex role of B lymphocytes in tumor immunity may become an important factor in tumor immunotherapy. In this review, we describe the development of B cells in tumor microenvironments. We then focus on the most controversial issues of the biological functions of B lymphocytes. Finally, we nominate B cells as therapeutic targets, which should open broad perspectives for the development of their clinical applications.

Prognostic significance of programmed cell death ligand 1 expression in patients with ovarian carcinoma: A systematic review and meta-analysis

BACKGROUND

Programmed cell death ligand 1 (PD-L1) overexpression has been reported to be associated with poor prognosis in several human cancers. However, studies on the prognostic value of PD-L1 expression in ovarian carcinoma (OC) remain controversial. This meta-analysis aimed to evaluate comprehensively the prognostic value of PD-L1 in OC.

METHODS

Electronic databases, including PubMed, EMBASE, and the Cochrane Library, were searched up until March 28, 2018. Hazard ratio (HR), along with 95% confidence interval (CI), was used to analyze the included outcomes.

RESULTS

A total of 10 studies with 1179 OC patients were included in this meta-analysis. There was no significant correlation between PD-L1 expression and overall survival (OS) (HR 1.23, 95% CI 0.85-1.79) and progression-free survival (PFS) (HR 0.88, 95% CI 0.52-1.47) of OC patients. However, the subgroup analysis suggested that positive PD-L1 expression was significantly associated with poor OS (HR 1.66, 95% CI 1.08-2.55) and PFS (HR 2.17, 95% CI 1.31-3.61) among OC patients from Asian countries. Increased PD-L1 expression was also a favorable factor for OS (HR 0.73, 95% CI 0.53-0.99) and PFS (HR 0.58, 95% CI 0.45-0.75) in OC patients from non-Asian regions. No evidence of publication bias was detected by the Egger linear regression test and Begg funnel plot. Sensitivity analyses suggested that the results of this meta-analysis were robust.

CONCLUSIONS

The results indicated that PD-L1 expression may be a negative predictor for prognosis of OC patients from Asian countries, and a good predictor for favorable prognosis of OC patients from non-Asian countries. PD-L1 expression has potential to be a prognostic biomarker to guide clinicians for the selection of individuals who may get clinical benefit from anti-PD-1/PD-L1 immunotherapy. Prospective clinical studies are needed to support these findings.

Immune checkpoint inhibitors of CTLA4 and PD-1 for malignant melanoma arising in ovarian cystic teratoma: A case report

RATIONALE

Malignant melanoma (MM) arising in ovarian cystic teratoma (OCT) is a rare disease with poor prognosis. Recently, immune checkpoint inhibitors of cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) and programmed death 1 (PD-1) have shown promising results in MM. Herein we report a case of MM arising in OCT.

PATIENT CONCERNS

A 63-year-old Japanese primigravida had lower abdominal pain. Magnetic resonance imaging revealed the presence of an 85-mm mass at the right ovary.

DIAGNOSES

The patient underwent right salpingo-oophorectomy for right ovarian tumor, and histopathological examinations revealed MM arising in OCT. On immunohistochemical analysis, the tumor cells were positive for HMB-45, Melan A, and S-100 protein, and negative for programmed death-ligand 1 (PD-L1). BRAF gene mutations were not detected by the Real-Time PCR. Two months after surgery, liver metastasis was detected.

INTERVENTIONS

The patient underwent immune checkpoint inhibitors of CTLA4 (ipilimumab) and PD-1 (pembrolizumab and nivolumab). She had interstitial pneumonia associated with ipilimumab, but she safely underwent the immune checkpoint inhibitors therapy along with oral prednisolone. Pembrolizumab, ipilimumab, and nivolumab therapies had poor effect on the tumor.

OUTCOMES

Now, the present case has had tumor-bearing survival for 14 months since the initial diagnosis and 12 months since the detection of liver metastasis.

LESSONS

This is the first case of MM arising in OCT treated by immune checkpoint inhibitors, with information of PD-L1 immunohistochemical expression and adverse events. The present case is the longest survivor following the detection of recurrence among all the previous reports. The long survival and slow-growing tumor in the present case may be associated with no PD-L1 expressions.

Distribution of CD4+ and CD8+ exhausted tumor-infiltrating lymphocytes in molecular subtypes of Chinese breast cancer patients

PURPOSE

Breast cancer (BC) is the leading cancer affecting Chinese women; however, the immune microenvironment between molecular subtypes is less reported. This study aimed to investigate the distribution of tumor-infiltrating lymphocyte (TIL) subpopulations, especially exhausted CD4+ and CD8+ TILs in Chinese BC patients.

PATIENTS AND METHODS

A total of 133 patients with breast invasive ductal carcinoma were recruited consecutively from January 1, 2012 to December 31, 2013, and TILs were detected in H&E-stained sections. Expression profiling of PD-1, CD4, and CD8 was determined by immunohistochemistry on 4 µm formalin-fixed paraffin-embedded tissue sections. The distribution of TILs was analyzed based on hormone receptor status and molecular subtypes.

RESULTS

PD-1+, CD4+, and CD8+ TILs distributed differently based on molecular subtypes. Compared to Luminal A, triple-negative breast cancer (TNBC) patients had more PD-1+ TILs (39/high-power field [HPF] vs 11/HPF), PD-1+ helper T (CD4+) cells (28/HPF vs 10/HPF), and PD-1+ cytotoxic (CD8+) T-cells (3/HPF vs 2/HPF).

CONCLUSION

TILs are distributed differently based on molecular subtypes. TNBC patients exhibit more PD-1+ exhausted TILs, representing an inhibitory immune microenvironment. PD-1/PD-L1 pathway is a potential therapeutic target of TNBC.

Prognostic impact of the tumor immune microenvironment in synovial sarcoma

The association between the immune status within the tumor microenvironment and prognosis in synovial sarcoma is not well understood. We aimed to investigate the tumor immune microenvironment and analyze its prognostic impact for patients with synovial sarcoma. A total of 36 primary patients who were treated in our institution were retrospectively evaluated. Infiltration of lymphocytes (CD4+, CD8+, and FOXP3+), CD163+ macrophages, and expression of human leukocyte antigen (HLA) class I and programmed death ligand 1 (PD-L1) were evaluated by immunohistochemistry. Moreover, we investigated PD-L1 and programmed death ligand 2 (PD-L2) mRNA expression in 19 of the 36 cases, using real-time PCR. The Kaplan-Meier method was used to estimate overall survival and progression-free survival. Infiltration of lymphocytes and macrophages varied among the patients. Furthermore, the expression of HLA class I was negative or downregulated in 11 specimens. No PD-L1 expression was observed using immunohistochemistry. Moreover, although PD-L1 mRNA expression was observed in 18 of 19 specimens, the expression level was low. A higher infiltration of CD8+ or FOXP3+ lymphocytes in patients was associated with a favorable overall survival. In addition, a higher infiltration of CD163+ macrophages indicated a significantly worse overall and progression-free survival. Infiltration of CD4+ lymphocytes, HLA class I, PD-L1, and PD-L2 expression were not associated with patient prognosis. This represents the first report investigating the tumor immune microenvironment as a prognostic factor in synovial sarcoma, indicating that CD163+ macrophages are associated with tumor progression. Our results underscore the clinical significance of the tumor immune microenvironment in synovial sarcoma.

Assessment of PD-L1 expression across breast cancer molecular subtypes, in relation to mutation rate, BRCA1-like status, tumor-infiltrating immune cells and survival

To better understand the expression pattern of programmed death-ligand 1 (PD-L1) expression in different breast cancer types, we characterized PD-L1 expression in tumor and tumor-infiltrating immune cells, in relation to mutation rate, BRCA1-like status and survival. We analyzed 410 primary treatment-naive breast tumors comprising 162 estrogen receptor-positive (ER+) and HER2-, 101 HER2+ and 147 triple-negative (TN) cancers. Pathologists quantified tumor-infiltrating lymphocytes (TILs) and PD-L1 expression in tumor cells and TILs using whole slides and tissue microarray. Mutation rate was assessed by DNA sequencing, BRCA1-like status using multiplex ligation-dependent probe amplification, and immune landscape by multiplex image analyses of CD4, CD68, CD8, FOXP3, cytokeratin, and PD-L1. Half of PD-L1 scores evaluated by tissue microarray were false negatives compared to whole slide evaluations. We observed at least 1% of PD-L1-positive (PD-L1+) cells in 53.1% of ER+HER2-, 73.3% of HER2+, and 84.4% of TN tumors. PD-L1 expression was higher in ductal compared to lobular carcinomas, also within ER+HER2- tumors (p = 0.04). High PD-L1+ TILs score (> 50%) was independently associated with better outcome in TN tumors (HR = 0.27; 95%CI = 0.10-0.69). Within TN tumors, PD-L1 and TIL scores showed a modest but significant positive association with the number of silent mutations, but no association with BRCA1-like status. Multiplex image analyses indicated that PD-L1 is expressed on multiple immune cells (CD68+ macrophages, CD4+, FOXP3+, and CD8+ T cells) in the breast tumor microenvironment, independent of the PD-L1 status of the tumor cells. We found no evidence that levels of PD-L1+ TILs in TN breast cancer are driven by high mutation rate or BRCA1-like status.

Assessment of programmed cell death ligand-1 expression by 4 diagnostic assays and its clinicopathological correlation in a large cohort of surgical resected non-small cell lung carcinoma

Immune checkpoint blockade targeting the PD-1/PD-L1 axis has recently demonstrated efficacy and promise in cancer treatment. Appropriate biomarker selection is therefore essential for improving treatment efficacy. However, the establishment of PD-L1 assay in pathology laboratories is complicated by the presence of multiple testing platforms using different scoring systems. Here we assessed the PD-L1 expression in 713 consecutive non-small cell lung carcinomas by four commercially available PD-L1 immunohistochemical assays, namely, 22C3, 28-8, SP142 and SP263. The analytical performances of the four assays and diagnostic performances across clinically relevant cutoffs were evaluated. The prevalence of PD-L1 (22C3) expression was 21% with a ≥50% cutoff and 56% with a ≥1% cutoff. High PD-L1 expression (using a ≥50% cutoff) was significantly associated with male sex (P = 0.001), ever smoking history (P < 0.001), squamous cell carcinoma (P = 0.001), large cell carcinoma (P < 0.001), lymphoepithelioma-like carcinoma (P = 0.006), sarcomatoid carcinoma (P < 0.001), mutant KRAS (P = 0.005) and wild-type EGFR (P = 0.003). Elevated PD-L1 expression was also significantly associated with shorter survival in patients with adenocarcinoma (log-rank P = 0.026) and remained an independent prognostic factor by multivariable analysis. Among the four assays, 22C3, 28-8 and SP263 were highly concordant for tumor cell scoring. With a cutoff of ≥50% (i.e., the threshold for first-line patient selection), inter-rater agreement was high among the three assays with percentage agreement >97%. In conclusion, three PD-L1 assays showed good analytical performance and a high agreement with each other, but not all cases were correctly classified using the same clinical cutoff. Further studies comparing the predictive value of these assays are required to address the interchangeability of these assays for clinical use.

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.

BET proteins in abnormal metabolism, inflammation, and the breast cancer microenvironment

Obesity and its associated pathology Type 2 diabetes are two chronic metabolic and inflammatory diseases that promote breast cancer progression, metastasis, and poor outcomes. Emerging critical opinion considers unresolved inflammation and abnormal metabolism separately from obesity; settings where they do not co-occur can inform disease mechanism. In breast cancer, the tumor microenvironment is often infiltrated with T effector and T regulatory cells programmed by metabolic signaling. The pathways by which tumor cells evade immune surveillance, immune therapies, and take advantage of antitumor immunity are poorly understood, but likely depend on metabolic inflammation in the microenvironment. Immune functions are abnormal in metabolic disease, and lessons learned from preclinical studies in lean and metabolically normal environments may not translate to patients with obesity and metabolic disease. This problem is made more urgent by the rising incidence of breast cancer among women who are not obese but who have metabolic disease and associated inflammation, a phenotype common in Asia. The somatic BET proteins, comprising BRD2, BRD3, and BRD4, are new critical regulators of metabolism, coactivate transcription of genes that encode proinflammatory cytokines in immune cell subsets infiltrating the microenvironment, and could be important targets in breast cancer immunotherapy. These transcriptional coregulators are well known to regulate tumor cell progression, but only recently identified as critical for metabolism, metastasis, and expression of immune checkpoint molecules. We consider interrelationships among metabolism, inflammation, and breast cancer aggressiveness relevant to the emerging threat of breast cancer among women with metabolic disease, but without obesity.

Genetic, transcriptional and post-translational regulation of the programmed death protein ligand 1 in cancer: biology and clinical correlations

The programmed death protein 1 (PD-1) and its ligand (PD-L1) represent a well-characterized immune checkpoint in cancer, effectively targeted by monoclonal antibodies that are approved for routine clinical use. The regulation of PD-L1 expression is complex, varies between different tumor types and occurs at the genetic, transcriptional and post-transcriptional levels. Copy number alterations of PD-L1 locus have been reported with varying frequency in several tumor types. At the transcriptional level, a number of transcriptional factors seem to regulate PD-L1 expression including HIF-1, STAT3, NF-κΒ, and AP-1. Activation of common oncogenic pathways such as JAK/STAT, RAS/ERK, or PI3K/AKT/MTOR, as well as treatment with cytotoxic agents have also been shown to affect tumoral PD-L1 expression. Correlative studies of clinical trials with PD-1/PD-L1 inhibitors have so far shown markedly discordant results regarding the value of PD-L1 expression as a marker of response to treatment. As the indications for immune checkpoint inhibition broaden, understanding the regulation of PD-L1 in cancer will be of utmost importance for defining its role as predictive marker but also for optimizing strategies for cancer immunotherapy. Here, we review the current knowledge of PD-L1 regulation, and its use as biomarker and as therapeutic target in cancer.

Prognostic Role and Clinical Association of Tumor-Infiltrating Lymphocyte, Programmed Death Ligand-1 Expression with Neutrophil-Lymphocyte Ratio in Locally Advanced Triple-Negative Breast Cancer

Purpose

Tumor-infiltrating lymphocyte (TIL), programmed death-ligand 1 (PD-L1) expression and neutrophil-to-lymphocyte ratio (NLR) is associated to immunogenicity and prognosis of breast cancer. We analyzed baseline NLR, changes of NLR, TIL, and PD-L1 during neoadjuvant chemotherapy (NAC) and their clinical implication in triple-negative breast cancer (TNBC).

Materials and Methods

Between January 2008 to December 2015, 358 TNBC patients were analyzed. Baseline NLR, 50 paired NLR (initial diagnosis, after completion of NAC) and 34 paired tissues (initial diagnosis, surgical specimen after completion of NAC) were collected. Changes of TIL, CD4, CD8, forkhead box P3 (FOXP3), and PD-L1 expression were assessed with immunohistochemical stain.

Results

Low NLR (≤ 3.16) was associated to superior survival (overall survival: 41.83 months vs. 36.5 months, p=0.002; disease-free survival [DFS]: 37.85 months vs. 32.14 months, p=0.032). Modest NLR change after NAC (–30% < NLR change < 100%) showed prolonged DFS (38.37 months vs. 22.37 months, p=0.015). During NAC, negative or negative conversion of tumor PD-L1 expression was associated to poor DFS (34.77 months vs. 16.03 months, p=0.037), and same or increased TIL showed trends for superior DFS, but without statistical significance. Positive tumor PD-L1 expression (H-score ≥ 5) in baseline or post-NAC tissue was associated to superior DFS (57.6 months vs. 12.5 months, p=0.001 and 53.3 months vs. 18.9 months, p=0.040). Positive stromal PD-L1 expression in baseline was also associated to superior DFS (50.2 months vs. 20.4 months, p=0.002).

Conclusion

In locally advanced TNBC, baseline NLR, changes of NLR during NAC was associated to survival. Baseline PD-L1 expression and changes of PD-L1 expression in tumor tissue during NAC also showed association to prognosis.

Characterizing parathyroid carcinomas and atypical neoplasms based on the expression of programmed death-ligand 1 expression and the presence of tumor-infiltrating lymphocytes and macrophages

BACKGROUND

Four distinct tumor microenvironments have been proposed based on the expression of programmed death-ligand 1 and the presence of tumor-infiltrating lymphocytes: immunotype I (adaptive resistance, tumor-infiltrating lymphocytes+ and programmed death-ligand 1+); immunotype II (immunologic ignorance, tumor-infiltrating lymphocytes- and programmed death-ligand 1-); immunotype III (intrinsic induction; tumor-infiltrating lymphocytes- and programmed death-ligand 1+); and immunotype IV (tolerance, tumor-infiltrating lymphocytes+ and programmed death-ligand 1-). These subtypes may predict tumor response to immunotherapy. We hypothesized that parathyroid neoplasms may have tumor immunogenic expression that can later be used to guide treatment.

METHODS

We assessed retrospectively the immunohistochemical expression of programmed death-ligand 1 and the presence of tumor-infiltrating lymphocytes (CD3+ and CD8+) and macrophages (CD68+) in parathyroid carcinomas and in atypical parathyroid neoplasms treated at the M. D. Anderson Cancer Center from 1996 to 2016. Using intratumoral digital image analysis, the programmed death-ligand 1 H score was calculated with a standardized formula for predominant staining. The tumor-infiltrating lymphocytes per square millimeter of intratumoral areas were quantified.

RESULTS

Within 30 specimens (17 parathyroid carcinomas and 13 atypical parathyroid neoplasms), there was no difference in the median programmed death-ligand 1 H score between the two groups (P = .57). Four parathyroid carcinoma cases had programmed death-ligand 1 H scores ≥1 associated with CD3+ and CD8+ tumor cell density; 2 of them had distant metastases. Parathyroid carcinomas had a lesser median CD3+ density (P = .04) and a lesser median CD8+ density (P =.07) than did atypical parathyroid neoplasms. Median CD68+ density did not differ between groups (P = .22).

CONCLUSION

Parathyroid carcinomas tended to have immune-ignorant and immune-tolerant microenvironments within the neoplasm (immunotypes II and IV). Of the parathyroid carcinoma microenvironments, 17 had patterns of programmed death-ligand 1 and tumor-infiltrating lymphocytes expression (immunotype I), suggesting possible benefit from immunotherapy. In addition, both parathyroid carcinomas and parathyroid neoplasms expressed CD68+. Further exploration of these potential biomarkers as a target in cancer therapies is needed.

Glyco-Engineered Anti-Human Programmed Death-Ligand 1 Antibody Mediates Stronger CD8 T Cell Activation Than Its Normal Glycosylated and Non-Glycosylated Counterparts

The programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis plays a central role in suppression of anti-tumor immunity. Blocking the axis by targeting PD-L1 with monoclonal antibodies is an effective and already clinically approved approach to treat cancer patients. Glyco-engineering technology can be used to optimize different properties of monoclonal antibodies, for example, binding to FcγRs. We generated two glycosylation variants of the same anti-PD-L1 antibody: one bearing core fucosylated N-glycans in its Fc part (92%) and its de-fucosylated counterpart (4%). The two glycosylation variants were compared to a non-glycosylated commercially available anti-PD-L1 antibody in various assays. No differences were observed regarding binding to PD-L1 and blocking of this interaction with its counter receptors PD-1 or CD80. The de-fucosylated anti-PD-L1 antibody showed increased FcγRIIIa binding resulting in enhanced antibody dependent cellular cytotoxicity (ADCC) activity against PD-L1⁺ cancer cells compared to the "normal"-glycosylated variant. Both glycosylation variants showed no antibody-mediated lysis of B cells and monocytes. The non-glycosylated reference antibody showed no FcγRIIIa engagement and no ADCC activity. Using mixed leukocyte reaction it was observed that the de-fucosylated anti-PD-L1 antibody induced the strongest CD8 T cell activation determined by expression of activation markers, proliferation, and cytotoxicity against cancer cells. The systematic comparison of anti-PD-L1 antibody glycosylation variants with different Fc-mediated potencies demonstrates that our glyco-optimization approach has the potential to enhance CD8 T cell-mediated anti-tumor activity which may improve the therapeutic benefit of anti-PD-L1 antibodies.

Progress in targeted therapy for breast cancer

Breast cancer is a multistep, multifactorial, and heterogeneous disease. Significant transformations have occurred in the systemic management of breast cancer in the past decade. Due to the further understanding of pathogenesis, scientists have found plenty of signaling pathways and correspondingly therapeutic targets in breast cancer, such as hormone receptor, human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), phosphoinositide-3-kinase (PI3K), v-akt murine thymoma viral oncogene homolog (AKT), mechanistic target of rapamycin (mTOR), cyclin-dependent kinase 4/6 (CDK4/6), poly (adenosine diphosphate-ribose) polymerase (PARP), and programmed death-1 (PD-1). Targeted therapy, which optimizes the accuracy of antitumor activity and minimizes toxicity to normal tissues, plays a crucial role in breast cancer treatment in the era of precision medicine. In this review, we aimed to summarize the latest developments in targeted therapy for breast cancer and discuss the existing problems.

Biomarkers in breast cancer: A consensus statement by the Spanish Society of Medical Oncology and the Spanish Society of Pathology

This consensus statement revises and updates the recommendations for biomarkers use in the diagnosis and treatment of breast cancer, and is a joint initiative of the Spanish Society of Medical Oncology and the Spanish Society of Pathology. This expert group recommends determining in all cases of breast cancer the histologic grade and the alpha-estrogen receptor (ER), progesterone receptor, Ki-67 and HER2 status, in order to assist prognosis and establish therapeutic options, including hormone therapy, chemotherapy and anti-HER2 therapy. One of the four available genetic prognostic platforms (MammaPrint^®, Oncotype DX^®, Prosigna^® or EndoPredict^®) may be used in node-negative ER-positive patients to establish a prognostic category and decide with the patient whether adjuvant treatment may be limited to hormonal therapy. Newer technologies including next-generation sequencing, liquid biopsy, tumour-infiltrating lymphocytes or PD-1 determination are at this point investigational.

Oncolytic Reovirus and Immune Checkpoint Inhibition as a Novel Immunotherapeutic Strategy for Breast Cancer

As the current efficacy of oncolytic viruses (OVs) as monotherapy is limited, exploration of OVs as part of a broader immunotherapeutic treatment strategy for cancer is necessary. Here, we investigated the ability for immune checkpoint blockade to enhance the efficacy of oncolytic reovirus (RV) for the treatment of breast cancer (BrCa). In vitro, oncolysis and cytokine production were assessed in human and murine BrCa cell lines following RV exposure. Furthermore, RV-induced upregulation of tumor cell PD-L1 was evaluated. In vivo, the immunocompetent, syngeneic EMT6 murine model of BrCa was employed to determine therapeutic and tumor-specific immune responses following treatment with RV, anti-PD-1 antibodies or in combination. RV-mediated oncolysis and cytokine production were observed following BrCa cell infection and RV upregulated tumor cell expression of PD-L1. In vivo, RV monotherapy significantly reduced disease burden and enhanced survival in treated mice, and was further enhanced by PD-1 blockade. RV therapy increased the number of intratumoral regulatory T cells, which was reversed by the addition of PD-1 blockade. Finally, dual treatment led to the generation of a systemic adaptive anti-tumor immune response evidenced by an increase in tumor-specific IFN-γ producing CD8⁺ T cells, and immunity from tumor re-challenge. The combination of PD-1 blockade and RV appears to be an efficacious immunotherapeutic strategy for the treatment of BrCa, and warrants further investigation in early-phase clinical trials.

Expression of programmed cell death protein 1 (PD-1) and its ligand PD-L1 in colorectal cancer: Relationship with sidedness and prognosis

Expression of programmed cell death protein 1 (PD-1) and its ligand PD-L1 has been demonstrated to confer a prognostic value in colorectal cancer (CRC), but no studies have investigated whether this association differs according to tumour location. In this study, immunohistochemical expression of PD-1 and PD-L1 was analysed in tissue microarrays with primary tumours from 557 incident CRC cases from a prospective population-based cohort. Univariable and multivariable Cox regression analyses, adjusted for age, sex, TNM stage, differentiation grade and vascular invasion, were applied to determine the impact of biomarker expression on 5-year overall survival (OS), in the entire cohort and in subgroup analysis of right colon, left colon, and rectum. High PD-L1 expression on tumour-infiltrating immune cells was an independent factor of a prolonged OS in the entire cohort (hazard ratio [HR] = 0.49; 95% confidence interval [CI] CI 0.35 – 0.68), and in tumours of the right colon (HR = 0.43; 95% CI 0.25 – 0.74) and the left colon (HR = 0.28; 95% CI 0.13 – 0.61), but not in rectal cancer. Tumour-specific PD-L1-expression was not prognostic, neither in the full cohort nor according to tumour location. High immune cell-specific PD-1 expression was associated with a prolonged OS in the entire cohort and in tumours of the right colon, but not in the left colon or rectum, and only in univariable analysis. In conclusion, these results demonstrate that immune cell-specific PD-L1 and PD-1 expression is prognostic in a site-dependent manner, whereas tumour-specific PD-L1-expression is not prognostic in CRC.

Clinicopathological and prognostic significance of PD-L1 expression in sarcoma: A systematic review and meta-analysis

Programmed cell death-ligands 1 (PD-L1) is a key immune checkpoint protein and a promising therapeutic target for malignancy tumor immunotherapy. The prognostic value of PD-L1 in patients with bone and soft tissue sarcoma remains controversial. Therefore, this meta-analysis is conducted to evaluate the associations of PD-L1 expression with overall survival (OS), progression-free survival (PFS), and clinicopathological characteristics of sarcomaA comprehensive literature search of PubMed, Web of Science, Embase, and Cochrane Library was conducted for relevant studies. A total of 14 studies published from 2013 to 2017 were included. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted from included studies to assess the association between PD-L1 expression and OS, PFS of patients with sarcoma. Other relevant data were extracted to evaluate the correlations of PD-L1 expression with risk and clinicopathological characteristics of sarcoma. Stata 12.0 software was applied to calculate the strength of association between PD-L1 expression and sarcoma.In total, 14 articles containing 15 independent studies and 1,451 patients were included in this meta-analysis. We found that the high PD-L1 expression was associated with poorer overall survival (HR 1.27, 95% CI: 0.70-1.84 P = .000) and poorer events-free survival (HR 2.05, 95% CI: 1.55-2.70, P = .000) in bone and soft-tissue sarcoma patients. Additionally, we conducted subgroup analysis according to histology type, ethnicity, target of PD-L1 assessment, cutoff, the significant correlations with poor overall survival and events-free survival were also observed. In contrast none of the clinicopathological characteristics (gender, age, tumor site, tumor grade, tumor depth, tumor necrosis rate, metastasis, recurrence, chemotherapy, radiotherapy) was found to be associated with PD-L1 expression in our analysis.The findings from this meta-analysis indicate that PD-L1 expression might be a useful predicative factor of poor prognosis for patients with bone and soft tissue sarcoma.

Neoadjuvant Therapy for Breast Cancer: Established Concepts and Emerging Strategies

In the last decade, the systemic treatment approach for patients with early breast cancer has partly shifted from adjuvant treatment to neoadjuvant treatment. Systemic treatment administration started as a 'one size fits all' approach but is currently customized according to each breast cancer subtype. Systemic treatment in a neoadjuvant setting is at least as effective as in an adjuvant setting and has several additional advantages. First, it enables response monitoring and provides prognostic information; second, it downstages the tumor, allowing for less extensive surgery, improved cosmetic outcomes, and reduced postoperative complications such as lymphedema; and third, it enables early development of new treatment strategies by using pathological complete remission as a surrogate outcome of event-free and overall survival. In this review we give an overview of the current standard of neoadjuvant systemic treatment strategies for the three main subtypes of breast cancer: hormone receptor-positive, triple-negative, and human epidermal growth factor receptor 2-positive. Additionally, we summarize drugs that are under investigation for use in the neoadjuvant setting.

The combined presence of CD20 + B cells and PD-L1 + tumor-infiltrating lymphocytes in inflammatory breast cancer is prognostic of improved patient outcome

PURPOSE

The purpose of the study was to evaluate protein expression of PD-L1 and CD20 as prognostic biomarkers of patient outcome in inflammatory breast cancer (IBC) samples.

METHODS

PD-L1 and CD20 protein expression was measured by immunohistochemistry in 221 pretreatment IBC biopsies. PD-L1 was assessed in tumor cells (PD-L1⁺ tumor cells) and tumor stromal infiltrating lymphocytes (PD-L1⁺ TILs); CD20 was scored in tumor-infiltrating B cells. Kaplan-Meier curves and Cox proportional hazard models were used for survival analysis.

RESULTS

PD-L1⁺ tumor cells, PD-L1⁺ TILs, and CD20⁺ TILs were found in 8%, 66%, and 62% of IBC, respectively. PD-L1⁺ tumor cells strongly correlated with high TILs, pathological complete response (pCR), CD20⁺ TILs, but marginally with breast cancer-specific survival (BCSS, P = 0.057). PD-L1⁺ TILs strongly correlated with high TILs, CD20⁺ TILs, and longer disease-free survival (DFS) in all IBC and in triple-negative (TN) IBC (P < 0.035). IBC and TN IBC patients with tumors containing both CD20⁺ TILs and PD-L1⁺ TILs (CD20⁺TILs/PD-L1⁺TILs) showed longer DFS and improved BCSS (P < 0.002) than patients lacking both, or those with either CD20⁺ TILs or PD-L1⁺ TILs alone. In multivariate analyses, CD20⁺TILs/PD-L1⁺TILs status was an independent prognostic factor for DFS in IBC (hazard ratio (HR): 0.53, 95% CI 0.37-0.77) and TN IBC (HR: 0.39 95% CI 0.17-0.88), and for BCSS in IBC (HR: 0.60 95% CI 0.43-0.85) and TN IBC (HR: 0.38 95% CI 0.17-0.83).

CONCLUSION

CD20⁺TILs/PD-L1⁺TILs status represents an independent favorable prognostic factor in IBC and TN IBC, suggesting a critical role for B cells in antitumor immune responses. Anti-PD-1/PD-L1 and B cell-activating immunotherapies should be explored in these settings.

Breast Cancer Immunotherapy: An Update

The immune system plays a major role in cancer surveillance. Harnessing its power to treat many cancers is now a reality that has led to cures in hopeless situations where no other solutions were available from traditional anticancer drugs. These spectacular achievements rekindled the oncology community's interest in extending the benefits to all cancers including breast cancer. The first section of this article reviews the biological foundations of the immune response to different subtypes of breast cancer and the ways cancer may overcome the immune attack leading to cancer disease. The second section is dedicated to the actual immune treatments including breast cancer vaccines, checkpoint inhibitors, monoclonal antibodies, and the "unconventional" immune role of chemotherapy.

Expression and clinical significance of programmed death ligand 1 in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) has the highest incidence of all types of head and neck cancer in China. The present study aimed to investigate the association between the expression of programmed death ligand 1 (PD-L1) in NPC tissues and clinicopathological features, as well the outcomes for NPC patients. In addition, the association between tissue expression of PD-L1 and immune components in peripheral blood was assessed. The expression of PD-L1 was determined by immunohistochemistry, while immune indexes were determined by ELISA and flow cytometry. The positive expression rate of PD-L1 in NPC patients was 29.2%, and the PD-L1 expression levels were associated with distant metastasis (P=0.010) and the T-stage of the primary tumor (P=0.032). The expression of PD-L1 was associated with the distant metastasis-free survival of NPC patients (P=0.006). In addition, a statistically significant association of PD-L1 expression with Epstein-Barr virus viral capsid antigen IgA (EBV VCA-IgA; P=0.046) and with CD3^-CD19⁺ cells (P=0.014) was identified. These results indicated that PD-L1 may be a potential prognostic biomarker for NPC patients, and that EBV VCA-IgA and CD3^-CD19⁺ cells may be useful for predicting PD-L1 expression when its levels cannot be detected due to the lack of a tumor tissue sample.

Eya3 promotes breast tumor-associated immune suppression via threonine phosphatase-mediated PD-L1 upregulation

Eya proteins are critical developmental regulators that are highly expressed in embryogenesis but downregulated after development. Amplification and/or re-expression of Eyas occurs in many tumor types. In breast cancer, Eyas regulate tumor progression by acting as transcriptional cofactors and tyrosine phosphatases. Intriguingly, Eyas harbor a separate threonine (Thr) phosphatase activity, which was previously implicated in innate immunity. Here we describe what we believe to be a novel role for Eya3 in mediating triple-negative breast cancer-associated immune suppression. Eya3 loss decreases tumor growth in immune-competent mice and is associated with increased numbers of infiltrated CD8+ T cells, which, when depleted, reverse the effects of Eya3 knockdown. Mechanistically, Eya3 utilizes its Thr phosphatase activity to dephosphorylate Myc at pT58, resulting in a stabilized form. We show that Myc is required for Eya3-mediated increases in PD-L1, and that rescue of PD-L1 in Eya3-knockdown cells restores tumor progression. Finally, we demonstrate that Eya3 significantly correlates with PD-L1 in human breast tumors, and that tumors expressing high levels of Eya3 have a decreased CD8+ T cell signature. Our data uncover a role for Eya3 in mediating tumor-associated immune suppression, and suggest that its inhibition may enhance checkpoint therapies.

High Serum Level of Soluble Programmed Death Ligand 1 is Associated With a Poor Prognosis in Hodgkin Lymphoma

Blockade of the programmed cell death 1-programmed cell death ligand 1 pathway is a new and promising therapeutic approach in Hodgkin lymphoma (HL). To our knowledge, the impact of soluble programmed cell death ligand 1 (sPD-L1) serum levels on HL patient prognosis has not yet been investigated. In this study, the prognostic value of sPD-L1 was assessed in patients with HL. We measured serum sPD-L1 levels and identified their prognostic value in 108 newly diagnosed HL patients using an enzyme-linked immunosorbent assay (ELISA). We found higher serum sPD-L1 concentrations in HL patients than in healthy controls. The best sPD-L1 cutoff value for predicting disease progression risk was 25.1674 ng/ml. The 4-year progression-free survival (PFS) rates for the high-sPD-L1 and low-sPD-L1 groups were 78.8% and 93.3%, respectively. Multivariate survival analysis showed that advanced stage and higher sPD-L1 levels (>25.1674 ng/ml) were independent prognostic factors for shorter PFS. In addition, higher sPD-L1 levels were positively correlated with advanced stage and negatively correlated with peripheral blood monocyte number. The serum sPD-L1 level is an independent prognostic factor for PFS in HL patients and may allow identification of a subgroup of patients who require more intensive therapy and who may benefit from anti-PD-1 agents.

Clinicopathological analysis of epithelioid inflammatory myofibroblastic sarcoma

Inflammatory myofibroblastic tumor (IMT) is a distinctive neoplasm composed of myofibroblastic and fibroblastic spindle cells, accompanied by the inflammatory infiltration of plasma cells, lymphocytes and/or eosinophils. Epithelioid inflammatory myofibroblastic sarcoma (EIMS), which primarily consists of cells with a round or epithelioid morphology, is associated with a poor prognosis and rapid development of local recurrence, and has been recognized to be a variant of IMT. Diagnosis of EIMS is difficult owing to its close resemblance to malignant mesothelioma, anaplastic large cell lymphoma, gastrointestinal stromal tumor and other malignant diseases. In the present study, a case of this rare tumor was evaluated in a 26-year-old male who was admitted to hospital after experiencing abdominal pain for ~18 days and abdominal distention for 1 week. The patient's tumor was examined by imaging, gross examination, histology, immunohistochemistry and fluorescence in situ hybridization (FISH). The magnetic resonance imaging enhanced-scanning image revealed that the morphology of the tumor was irregular, and signal was medley consisting of high and low hybrid reinforcement. Tumors were located in the bladder and rectal pit, in the lower part of the lower abdomen, indicating the presence of malignancy and involvement of the small intestine and rectum. Enhanced-scanning imaging revealed notable inhomogeneous enhancement. Gross examination revealed that the tumor was solid and had a variegated appearance with alternating fleshy and mucoid areas in the cut surface. Microscopically, the tumors were dominated by sheets of epithelioid-to-round cells with a prominent inflammatory infiltrate. The majority of the stroma was myxoid. Immunohistochemically, the tumor cells exhibited diffuse strong staining for ALK receptor tyrosine kinase (hereafter ALK), vimentin, tumor protein P53, desmin, Wilms' tumor 1 and programmed death-ligand 1. FISH analysis also revealed the existence of ALK rearrangement. The expression of PD-L1 in EIMS indicates that the immune checkpoint blockade could represent a novel therapy for the treatment of EIMS.

Type Iγ phosphatidylinositol phosphate kinase regulates PD-L1 expression by activating NF-κB

The programmed death-ligand 1 (PD-L1), by binding to PD-1 on the surface of immune cells, activates a major immune checkpoint pathway. Elevated expression of PD-L1 in tumor cells mediates tumor-induced T-cell exhaustion and immune suppression; therefore protect the survival of tumor cells. Although blockade of the PD-1/PD-L1 axis exhibits great potential in cancer treatment, mechanisms driving the up-regulation of PD-L1 in tumor cells remain not fully understood. Here we found that type Iγ phosphatidylinositol 4-phosphate (PtdIns(4)P) 5-kinase (PIPKIγ) is required for PD-L1 expression in triple negative breast cancer cells. Depletion of PIPKIγ inhibits both intrinsic and induced PD-L1 expression. Results from further analyses suggest that PIPKIγ promotes the transcription of the PD-L1 gene by activating the NF-κB pathway in these cells. These results demonstrate that PIPKIγ-dependent expression of PD-L1 is likely important for the progression of triple negative breast cancer.

Prediction of treatment responses to neoadjuvant chemotherapy in triple-negative breast cancer by analysis of immune checkpoint protein expression

Background

“Avoiding immune destruction” has recently been established as one of the hallmarks of cancer. The programmed cell death (PD)-1/programmed cell death-ligand (PD-L) 1 pathway is an important immunosuppression mechanism that allows cancer cells to escape host immunity. The present study investigated how the expressions of these immune checkpoint proteins affected responses to neo-adjuvant chemotherapy (NAC) in breast cancer.

Methods

A total of 177 patients with resectable early-stage breast cancer were treated with NAC. Estrogen receptor, progesteron receptor, human epidermal growth factor receptor 2, Ki67, PD-L1, PDL-2 and PD-1 status were assessed by immunohistochemistry.

Results

There were 37 (20.9%) patients with high PD-1 expression, 42 (23.7%) patients had high PD-L1 expression, and 52 (29.4%) patients had high PD-L2 expression. The patients with high PD-1 and PD-L1 expressions had a significantly higher rate of triple-negative breast cancer (TNBC) (p = 0.041) (p < 0.001). In TNBC, patients with high PD-1 and PD-L1 expressions had significantly higher rates of non-pCR (p = 0.003) (p < 0.001). Univariate analysis showed that PD-1 and PD-L1 expressions also significantly shortened disease free survival in TNBC (p = 0.048, HR = 3.318) (p = 0.007, HR = 8.375). However, multivariate analysis found that only PD-L1 expression was an independent prognostic factor (p = 0.041, HR = 9.479).

Conclusions

PD-1 and PD-L1 expressions may be useful as biomarkers to predict treatment responses to NAC in breast cancer. Above all, PD-L1 expression may also be useful as biomarkers for more effective chemotherapy in TNBC.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1458-y) contains supplementary material, which is available to authorized users.

PD-L1 immuno-expression assay in thymomas: Study of 84 cases and review of literature

BACKGROUND AND AIMS

Programmed death ligand 1 (PD-L1), an immune check point inhibitor, is known to be expressed in several malignancies and is being considered as a prognostic factor and a potential immunotherapeutic target. The aim of this study was to characterize PD-L1 expression in thymomas and to determine correlation with clinicopathological features and previously published studies in the literature.

METHODS

Tissue microarrays were prepared from selected blocks of thymomas and immunohistochemistry (IHC) for PD-L1 was performed. Cases were considered as PD-L1 positive or negative depending on whether the percentage of stained thymic epithelial cells were <25 or >25%. Results were compared clinically and with previously published studies using Google and Pubmed search engines.

RESULTS

Of 84 cases of thymoma, 69 (82.1%) revealed PD-L1 positivity in >25% cells. 94.23% of type B thymoma subtypes (B1/B2/B3) were PD-L1 positive (P < 0.001). There was no correlation of PD-L1 with age, gender, myasthenia gravis, the tumor size or stage of disease. Nine studies were available in the literature; most of which showed PD-L1 expression in higher stage and B subtype however percentage positivity varied from 53.7% to over 90%.

CONCLUSIONS

PD-L1 expression is frequent in type B (B1/B2/B3) thymomas. It can be easily evaluated by IHC even on small biopsies in unresectable cases, thereby enabling improved clinical evaluation as well as prognostic stratification of patients. It will serve as a potential indicator for benefit from anti-PD-L1 antibody immunotherapy in thymomas.

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.

Expression of PD-L1 and prognosis in breast cancer: a meta-analysis

The associations between programmed cell death ligand 1 (PD-L1) and the prognosis of various cancers have always been a research topic of considerable interest. However, the prognostic value of PD-L1 in breast cancer patients remains a controversial subject. We aimed to assess the association between PD-L1 protein expression and clinicopathological features and the impact of this relationship on breast cancer survival. We performed a systematic search of the PubMed, EMBASE, and Cochrane Library databases to determine the correlations among PD-L1 expression, clinicopathological features and overall survival (OS). A total of 5 studies containing 2,546 cases were included in the analysis. The combined hazard ratio (HR) and its 95% confidence interval (CI) for OS were 1.76 (95% CI 1.09–2.82; P=0.02) for patients with tumors exhibiting PD-L1 overexpression. The pooled odds ratios (ORs) indicated that PD-L1 expression was associated with positive lymph node metastasis, higher histological grades, estrogen receptor (ER)-negativity, and triple-negative breast cancer (TNBC). Our findings indicate that PD-L1 expression is a promising biomarker for the prognosis of breast cancer, and may be helpful to clinicians aiming to select the appropriate immunotherapy for breast cancer.

[Consensus statement on biomarkers in breast cancer by the Spanish Society of Pathology and the Spanish Society of Medical Oncology]

This consensus statement is a joint initiative of the Spanish Society of Pathology (SEAP) and the Spanish Society of Medical Oncology (SEOM). It revises and updates the recommendations for the use of biomarkers in the diagnosis and treatment of breast cancer. The group of experts recommends that, in all cases of breast cancer, the histologic grade and the alpha-estrogen receptor (ER), progesterone receptor, Ki-67 and HER2 status should be determined, in order to assist prognosis and establish therapeutic options, including hormone therapy, chemotherapy and anti-HER2 therapy. One of the four available genetic prognostic platforms (MammaPrint^®, Oncotype DX^®, Prosigna^® or EndoPredict^®) may be used in node-negative ER-positive patients to establish a prognostic category and decide, together with the patient, whether adjuvant treatment be limited to hormonal therapy. Newer technologies, including next generation sequencing, liquid biopsy, tumour infiltrating lymphocytes or PD-1 determination, are still investigational.

Immune-Related Concepts in Biology and Treatment of Germ-Cell Tumors

Germ-cell tumors (GCTs) are highly curable with chemotherapy. Salvage chemotherapy or surgery can cure a proportion of patients, but the ones failing these treatments will die of their disease in the young age. Immune checkpoint pathways are emerging as powerful targetable biomarkers, and a significant preclinical and clinical research is underway to widen our knowledge and expand the treatment possibilities with immune therapy. The concept of immune modulation that was currently adopted in many solid tumors is understudied in GCTs. Herein, we summarize the current knowledge of published literature discussing the immune mechanisms and immune therapy in GCTs.

The role of programmed death ligand-1 and tumor-infiltrating lymphocytes in breast cancer overexpressing HER2 gene

PURPOSE

The purpose of the study is to investigate the prognostic significance of programmed death ligand-1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs) in HER2+ breast cancer (BC).

METHODS

HER2+ BC cases (n  = 191) were collected between 1996 and 2013. Tissue microarray (TMA) slides were stained with two clones of PD-L1 antibodies (28-8 and 22C3) and the percentage of positive membranous staining was scored. TILs of the full sections were also scored using percentage scale.

RESULTS

Clone 28-8 had expression in ≥ 1% of the tumor cells in 25.7% of the cases, while clone 22C3 in ≥ 1% of the tumor cells was expressed in 11.5% of the cases. In the multivariate analysis, higher expression of PD-L1 (clone 28-8) in tumor correlated with lower risk of tumor recurrence, with HR of 0.4 (p = 0.033). Higher level of TILs (> 15%) predicts better overall survival (OS) in all patients with HR of 0.35 (p  = 0.0046). In the group of patients who were treated with trastuzumab-based adjuvant chemotherapy, lower PD-L1 (clone 28-8) expression in TILs correlated with tumor recurrence (p  = 0.034). In the group of patients who were treated with non-trastuzumab-based adjuvant chemotherapy, lower TILs and lower PD-L1 (clone 28-8) expression in tumor had borderline statistical significance in association with tumor recurrence (p  = 0.064 and 0.083, respectively). In the group of patients who were treated with trastuzumab-based adjuvant chemotherapy, PD-L1 or TILs was not statistically significant to predict 5-year survival. In the group of patients who were treated with non-trastuzumab-based adjuvant chemotherapy, low TILs (p = 0.009) correlated with 5-year death due to disease.

CONCLUSION

We conclude that PD-L1 may have prognostic significance in HER2+ BCs.

New Insights into Tumor-Infiltrating B Lymphocytes in Breast Cancer: Clinical Impacts and Regulatory Mechanisms

Currently, tumor-infiltrating B lymphocytes have been recognized as a new hallmark of breast cancer (BC). The function seems to be controversial, either with positive, negative, or no significance in BC’s prediction and prognosis. Moreover, B-cell infiltrates regulate tumor process through productions of antibodies and interleukin-10. The interactions with other lymphocytes and programmed death-1/PD-1 ligand axis are also documented. The regulatory mechanisms will eventually be incorporated into diagnostic and therapeutic algorithms, thus give guide to clinical treatment. In this review, we give new insights into clinical impacts and regulatory mechanisms of tumor-infiltrating B cells, which heralds a new era in immuno-oncology in BC treatment.

MicroRNA-152 regulates immune response via targeting B7-H1 in gastric carcinoma

MiR-152 has been reported may be involved in carcinogenesis in gastric cancer. However, its role has not been comprehensively investigated in gastric cancer. We found miR-152 in human gastric cancer tissues were significantly lower than that in matched adjacent normal tissues. Meanwhile, lower miR-152 was also found in gastric cancer cell lines. The stage, tumor size and lymph node metastasis rate were significant higher in low–miR-152 group in clinical patients. Furthermore, there was a marked correlation between the levels of miR-152 and B7-H1 mRNA in gastric cancer tissues. Mechanistically, miR-152 directly bind to B7-H1 3′ untranslated region in gastric cancer cell and inhibited B7-H1 expression. Functional study demonstrated that elevation of miR-152 enhanced T cells proliferation and effector cytokines production via inhibiting B7-H1/PD-1 pathway. In conclusion, our work identified a novel mechanism by which immune response is increased by expression of miR-152 via targeting B7-H1. MiR-152 may be a potential therapeutic approach for gastric cancer.

Prognostic significance of tumor-infiltrating immune cells and PD-L1 expression in esophageal squamous cell carcinoma

Programmed death-1 receptor (PD-1) and its ligand (PD-L1) play an integral role in regulating the immune response against cancer. This study investigated the prognostic significance of PD-L1 expression on tumor cells and tumor-infiltrating immune cells (TILs) in the tumor microenvironment in Chinese patients with esophageal squamous cell carcinoma (ESCC). Archival formalin-fixed, paraffin-embedded ESCC samples from treatment-naïve patients with ESCC after surgery or by diagnostic endoscopic biopsy were collected between 2004 and 2014. Expression of PD-L1 in ESCC tumor specimens was assessed by immunohistochemistry (IHC), and the degree of TIL infiltration was evaluated by examining hematoxylin and eosin-stained (H&E) specimens. PD-L1+ as defined as ≥1% of tumor cell membranes showing ≥1+ intensity. In 428 patients, specimens from 341 (79.7%) were PD-L1+. In the definitive treatment group (patients who received curative esophagectomy or definitive [chemo-]radiation therapy), PD-L1 positivity was associated with a significantly shorter DFS and OS. In the palliative chemotherapy group exhibited, neither PFS nor OS correlated significantly with PD-L1 expression. PD-L1 expression was positively associated with TIL density. In 17 paired tumor tissues collected before and after treatment, an increase in PD-L1 expression was associated with disease progression, whereas a decrease in PD-L1 expression was associated with response to chemotherapy or disease control. So, PD-L1 expression was associated with a significantly worse prognosis in patients with ESCC. These observations suggest that PD-L1 may play a critical role in ESCC cancer progression and provide a rationale for developing PD-L1 inhibitors for treatment of a subset of ESCC patients.

Targeting of interleukin (IL)-17A inhibits PDL1 expression in tumor cells and induces anticancer immunity in an estrogen receptor-negative murine model of breast cancer

The expression of IL-17A and programmed death ligand 1 (PDL1) is increased in estrogen receptor-negative breast cancer. IL-17A promotes tumor cell survival and invasiveness and inhibits the antitumor immune response. The PDL1-PD1 (programmed death protein 1) signaling pathway promotes escape from immune surveillance in tumor cells. The pro-tumor properties of IL-17A and PDL1 in various cancers have been previously examined; however, the relationship and roles of IL-17A and PDL1 in ER-negative breast cancer have not been evaluated. Therefore, we assessed whether IL-17A promotes PDL1 expression in tumor cells and whether targeting of IL-17A could inhibit ER-negative breast cancer progression in a murine model. Our study revealed that IL-17A promoted PDL1 expression in human and mouse cells. In the murine cancer model, targeting of IL-17A inhibited PDL1 expression in the tumor microenvironment, decreased the percentage of Treg cells in tumor-infiltrating lymphocytes, and promoted CD4+ and CD8+ T cells to secrete interferon gamma. More importantly, treatment with combined anti-IL-17A and anti-PDL1 antibodies enhanced antitumor effects in favor of tumor eradication. Thus, our study established a pro-tumor role of IL-17A in promoting tumor immune escape and supports the development of a novel cytokine immunotherapy against breast cancer.

TILGen: A Program to Investigate Immune Targets in Breast Cancer Patients - First Results on the Influence of Tumor-Infiltrating Lymphocytes

BACKGROUND

Despite advancements in the treatment of primary and metastatic breast cancer, many patients lack a durable response to these treatments. Patients with triple-negative breast cancer (TNBC) and human epidermal growth factor receptor 2(HER2)-positive breast cancer who do not have a pathological complete response (pCR) after neoadjuvant chemotherapy (NACT) have a very poor prognosis. Tumor-infiltrating lymphocytes (TILs) have been identified as a predictive marker for pCR after NACT in TNBC and HER2-positive breast cancer. These patient populations could also be suitable for novel treatment strategies including neoepitope-based therapies. This work analyses the effect of TILs on the pCR in neoadjuvantly treated patients in the TILGen study and presents the procedures aimed at establishing neoepitope-based therapies in this study.

METHODS

Neoadjuvantly treated HER2-positive and TNBC patients were eligible for the presented analysis concerning the association between TILs and pCR. A total of 146 patients could be identified within the TILGen study. TILs were evaluated as percentage of stromal tumor tissue in core biopsies at primary diagnosis. The phenotype 'lymphocyte-predominant breast cancer' (LPBC) was associated with pCR by logistic regression adjusted for estrogen receptor status, progesterone receptor status, HER2 status, age at diagnosis, and grading.

RESULTS

LPBC was seen in 24 (16.4%) patients. In this patient group, 66.7% achieved a pCR, while the pCR rate was 32.8% in patients with a low TIL count. The adjusted odds ratio was 6.60 (95% confidence interval 2.02-21.56; p < 0.01).

CONCLUSION

TILs are a strong predictor of pCR in TNBC and HER2-positive breast cancer patients. Implications for the use of this information including the effect on prognosis might help to identify patients most likely to benefit from a neoepitope-based therapy approach.

Clinicopathologic and Prognostic Significance of Programmed Cell Death Ligand 1 Expression in Patients with Non-Medullary Thyroid Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Evidence has shown that programmed cell death ligand 1 (PD-L1) overexpression is associated with poor prognosis and resistance to immune therapies in several human cancers. However, data on the prognostic significance of PD-L1 expression in thyroid cancer are limited and remain controversial. This systematic review and meta-analysis aimed to evaluate comprehensively the clinicopathologic significance and prognostic value of PD-L1 expression in non-medullary thyroid cancers.

METHODS

Electronic databases, including Medline/PubMed, EMBASE, and the Cochrane Library, were searched up until July 5, 2017. In total, seven comparisons (from six articles) comprising 1421 patients were included in the pooled analysis.

RESULTS

There was moderate quality evidence from four studies (n = 721) that shows positive PD-L1 expression was significantly associated with poor survival among thyroid cancer patients (pooled hazard ratio = 3.73 [confidence interval (CI) 2.75-5.06]). Increased PD-L1 expression was also found to be significantly associated with disease recurrence (odds ratio = 1.95 [CI 1.15-3.32]) and concurrent thyroiditis (odds ratio = 1.65 [CI 1.09-2.51]).

CONCLUSIONS

The results confirm the prognostic significance of PD-L1 expression in thyroid cancer patients. PD-L1 expression has the potential to be implemented as a prognostic biomarker used to guide clinicians in identifying patients with more aggressive cancers, and for the selection of individuals that would derive durable clinical benefit from anti-PD-1/PD-L1 immunotherapy. Prospective clinical trials will be useful to support these findings.

Independent prognostic role of PD-L1expression in patients with esophageal squamous cell carcinoma

Accumulating evidence has shown that PD-L1 expression is associated with clinicopathological features in various human malignancies. We searched for correlations between PD-L1 expression and clinicopathological data in esophageal squamous cell carcinoma (ESCC) patients. PD-L1 expression in primary tumors from 278 patients was evaluated using immunohistochemistry (IHC) in ESCC tissue microarray. Survival curves were constructed by using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazard regression models were performed to identify associations with outcome variables. Overall, tumoral PD-L1 expression (≥10%, 20% or 30% as cut-off value) was associated with favorable DFS and OS upon multivariate analysis. When the patients stratified into stage I-II (168, 60.4%) and stage III-IV (110, 39.6%), or with lymph node metastasis (133, 47.8%), the prognostic role was not consistent. In patients with stage I-II disease, tumoral PD-L1 expression (≥5%, 10%, 20% or 30%) was associated with better DFS and OS upon multivariate analysis. In patients without lymph node metastasis, tumoral PD-L1 expression (≥1%, 5%, 10%, 20%, or 30%) was associated with improved DFS and OS in univariate or multivariate analysis. However, PD-L1 expression was not correlated with prognosis in patients with stage III-IV disease or with lymph node metastasis. Our results for the first time showed the prognostic role of tumoral PD-L1 expression was variable in different stages and lymph node status of ESCC. Tumoral PD-L1 expression was independent favorable predictor in ESCC patients with Stage I-II disease or without lymph node metastasis, not in stage III-IV or lymph node metastasis.

Expression of Programmed Death Ligand 1 (PD-L1) in Posttreatment Primary Inflammatory Breast Cancers and Clinical Implications

OBJECTIVES

Inflammatory breast carcinoma (IBC) is rare but is the most lethal type of breast cancer. Programmed death ligand 1 (PD-L1) expression in IBCs has been understudied.

METHODS

In this study, tissue microarrays of 68 IBCs were immunostained with a PD-L1 antibody using an antibody clone (28-8) and detection system approved by the US Food and Drug Administration for selecting patients with non-small cell lung cancer and melanoma for anti-PD-L1 therapy.

RESULTS

Positive PD-L1 expression was found in 25 (36.8%) of 68 samples but was not significantly associated with the clinicopathologic variables examined. Univariate analysis of overall survival (OS) revealed that worse OS was significantly associated with positive PD-L1, negative estrogen receptor, and triple-negative status. The 5-year OS rate was 36.4% for patients with PD-L1-positive IBC and 47.3% for those with PD-L1-negative IBC. In multivariate analyses, PD-L1 status remained a statistically independent predictor of OS.

CONCLUSIONS

These findings indicate that PD-L1 inhibitors could potentially improve the clinical outcome of patients with PD-L1-positive IBC.

[PD-L1 expression and PD-1/PD-L1 inhibitors in breast cancer]

The development of immune checkpoints inhibitors represents one of the major recent advances in oncology. Monoclonal antibodies directed against the programmed cell death protein 1 (PD-1) or its ligand (PD-L1) provides durable disease control, particularly in melanoma, lung, kidney, bladder and head and neck cancers. The purpose of this review is to synthesize current data on the expression of PD-L1 in breast cancer and on the preliminary clinical results of PD-1/PD-L1 inhibitors in breast cancer patients. In breast cancer, PD-L1 expression is heterogeneous and is generally associated with the presence of tumor-infiltrating lymphocytes as well as the presence of poor-prognosis factors, such as young age, high grade, ER-negativity, PR-negativity, and HER-2 overexpression, high proliferative index, and aggressive molecular subtypes (triple negative, basal-like, HER-2-overexpressing). Its prognostic value remains controversial when assessed with immunohistochemistry, whereas it seems favorable in triple-negative cancers when assessed at the mRNA level. Early clinical trials with PD-1/PD-L1 inhibitors in breast cancer have shown efficacy in terms of tumor response and/or disease control in refractory metastatic breast cancers, notably in the triple-negative subtype. Many trials are currently underway, both in the metastatic and neo-adjuvant setting. A crucial issue is identification of biomarkers predictive of response to PD-1/PD-L1 inhibitors.

PD1 protein expression in tumor infiltrated lymphocytes rather than PDL1 in tumor cells predicts survival in triple-negative breast cancer

To determine PD1/PDL1 expression status in triple-negative breast cancer (TNBC) at both protein and mRNA levels, and to analyze the relationship between their expression and clinical parameters of the TNBC patients. Immunohistochemistry and RNAscope were used to semi quantitively evaluate PD1/PDL1 protein and mRNA expression in 195 TNBC cases on tissue microarrays. Tumor infiltrating lymphocyte (TILs) abundance was assessed using hematoxylin-eosin staining. Both tumor cells and TILs expressed PDL1. PDL1 protein and mRNA positivity was 6.7% and 74.4% respectively in tumor cells, and 31.3% and 50.9% respectively in TILs. PDL1 protein and mRNA expressions had no significant association with patient prognosis. PD1 protein was only detected in TILs (70.3% positivity). PD1 protein expression was significantly related to PDL1 expression, higher TIL abundance, Ki-67 index, basal-like subtypes, and distant metastasis. Furthermore, it was significantly associated with longer disease free survival (P<0.001) and overall survival (P = 0.004). There was no significant association between PD1 mRNA expression and clinicopathological characteristics. PD1/PDL1 protein and mRNA expressions were inconsistent (kappa = 0.705 and 0.061, respectively). PD1 protein expression in TILs, but not PDL1 in tumor cells, was a favorable prognostic factor in TNBC. PD1/PDL1 mRNA and protein expressions were inconsistent.

CD8+/FOXP3+ ratio and PD-L1 expression associated with survival in pT3N0M0 stage esophageal squamous cell cancer

Data describing relationships between the tumor immune microenvironment and patient outcome are limited for esophageal squamous cell cancer (ESCC). The present study investigated the prognostic values of programmed death-ligand 1 (PD-L1) expression and CD8+ or forkhead box protein 3+ (FOXP3+) tumor-infiltrating lymphocytes (TILs) in 133 pathological T3N0M0 stage ESCC patients who underwent radical resection without neoadjuvant or adjuvant therapy. CD8+ and FOXP3+ TIL densities as well as PD-L1 levels in tumor cells and lymphocytes, were assessed through immunohistochemical staining. Patient survival was not associated with CD8+ or FOXP3+ TILs alone, but PD-L1 expression and the CD8+/FOXP3+ ratio were independent predictors of both disease-free and overall survival. PD-L1 expression correlated with age (p = 0.029), tumor length (p < 0.001), tumor differentiation status (p = 0.002) and reduced intratumoral CD8+ TIL density (p < 0.001). Our results suggest pT3N0M0 ESCC clinical outcomes correlate with CD8+ and FOXP3+ TIL densities and PD-L1 levels. Moreover, an intrinsic mechanism for induction of PD-L1 overexpression may be occurring during early tumor oncogenesis. This information may be useful for stratifying patients and guide the application of checkpoint blockade therapy in ESCC.

PD-1/PD-L1 in disease

Aim: Expression of PD-1 on T/B cells regulates peripheral tolerance and autoimmunity. Binding of PD-1 to its ligand, PD-L1, leads to protection against self-reactivity. In contrary, tumor cells have evolved immune escape mechanisms whereby overexpression of PD-L1 induces anergy and/or apoptosis of PD-1 positive T cells by interfering with T cell receptor signal transduction. PD-L1 and PD-1 blockade using antibodies are in human clinical trials as an alternative cancer treatment modality. Areas covered: We describe the role of PD-1/PD-L1 in disease in the context of autoimmunity, neurological disorders, stroke and cancer. Conclusion: For immunotherapy/vaccines to be successful, the expression of PD-L1/PD-1 on immune cells should be considered, and the combination of checkpoint inhibitors and vaccines may pave the way for successful outcomes to disease.