PD-L1 expression is a favorable prognostic factor in early stage non-small cell carcinoma

Unique Immune Gene Expression Patterns in Bronchoalveolar Lavage and Tumor Adjacent Non-Neoplastic Lung Tissue in Non-Small Cell Lung Cancer

Background

The immune cells in the local environments surrounding non-small cell lung cancer (NSCLC) implicate the balance of pro- and antitumor immunity; however, their transcriptomic profiles remain poorly understood.

Methods

A transcriptomic microarray study of bronchoalveolar lavage (BAL) cells harvested from tumor-bearing lung segments was performed in a discovery group. The findings were validated (1) in published microarray datasets, (2) in an independent group by RT-qPCR, and (3) in non-diseased and tumor adjacent non-neoplastic lung tissue by immunohistochemistry and in BAL cell lysates by immunoblotting.

Result

The differential expression of 129 genes was identified in the discovery group. These genes revealed functional enrichment in Fc gamma receptor-dependent phagocytosis and circulating immunoglobulin complex among others. Microarray datasets analysis (n = 607) showed that gene expression of BAL cells of tumor-bearing lung segment was also the unique transcriptomic profile of tumor adjacent non-neoplastic lung of early stage NSCLC and a significantly gradient increase of immunoglobulin genes’ expression for non-diseased lungs, tumor adjacent non-neoplastic lungs, and tumors was identified (ANOVA, p < 2 × 10⁻¹⁶). A 53-gene signature was determined with significant correlation with inhibitory checkpoint PDCD1 (r = 0.59, p = 0.0078) among others, where the nine top genes including IGJ and IGKC were RT-qPCR validated with high diagnostic performance (AUC: 0.920, 95% CI: 0.831–0.985, p = 2.98 × 10⁻⁷). Increased staining and expression of IGKC revealed by immunohistochemistry and immunoblotting in tumor adjacent non-neoplastic lung tissues (Wilcoxon signed-rank test, p < 0.001) and in BAL cell lysates (p < 0.01) of NSCLC, respectively, were noted.

Conclusion

The BAL cells of tumor-bearing lung segments and tumor adjacent non-neoplastic lung tissues present a unique gene expression characterized by IGKC in relation to inhibitory checkpoints. Further study of humoral immune responses to NSCLC is warranted.

PD-L1 expression in lung adenocarcinoma harboring EGFR mutations or ALK rearrangements

OBJECTIVES

Expression of programmed cell death-ligand 1 (PD-L1) has been associated with clinical outcome of programmed cell death-1 (PD-1) pathway blockade in non-small cell lung cancer (NSCLC). The PD-L1 IHC 22C3 pharmDx assay, the only companion diagnostic for pembrolizumab therapy, has revealed that ∼30% of all NSCLCs express PD-L1 at a high level. The frequency of high PD-L1 expression in NSCLCs with known driver oncogenes has remained unclear, however.

MATERIALS AND METHODS

We retrospectively evaluated PD-L1 expression with the 22C3 assay in tumor tissue of 80 lung adenocarcinoma patients including 71 with EGFR mutations and 9 with ALK rearrangements, all of whom were treated with corresponding tyrosine kinase inhibitors (TKIs).

RESULTS

Of the 80 tumors analyzed, 26 (32.5%) had a PD-L1 tumor proportion score (TPS) of 1%-49% and 9 (11.3%) had a PD-L1 TPS of ≥50%; 35 (43.8%) thus had a PD-L1 TPS of ≥1%. Of the 71 tumors with EGFR mutations, 23 (32.4%) had a PD-L1 TPS of 1%-49% and 7 (9.9%) had a PD-L1 TPS of ≥50%. A PD-L1 TPS of ≥1% was not associated with any clinical characteristic examined. Progression-free survival on initial TKI treatment was significantly poorer for patients with a PD-L1 TPS of ≥1% than for those with a PD-L1 TPS of <1% (p = .016).

CONCLUSIONS

A subset of patients with EGFR mutations or ALK rearrangements had a PD-L1 TPS of ≥50%. Prospective studies are thus warranted to examine the efficacy of PD-1/PD-L1 inhibitors in such patients.

Assessment of programmed cell death ligand-1 expression with multiple immunohistochemistry antibody clones in non-small cell lung cancer

Background

Programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) have been identified as novel targets for immunotherapy, with PD-L1 as a potential predictive biomarker. However, a specific antibody for PD-L1 expression is an immediate requirement. Meanwhile, the clinicopathological identification of patients with positive PD-L1 remains unclear.

Methods

The present study adopted three anti-PD-L1 IHC antibodies, SP142, SP263, and UMAB228 to test PD-L1 expression in 84 non-small cell lung cancer (NSCLC) specimens. The concordance among antibodies was examined by analytical comparison, and the association between PD-L1 expression and clinicopathological factors was assessed.

Results

The samples from 41 (48.8%), 51 (60.7%), and 50 (59.5%) patients were detected as PD-L1 positive evaluated by antibody SP142, SP263, and UMAB228, respectively. The kappa coefficient was 0.53, 0.58, and 0.46 for SP263 vs. SP142, SP263 vs. UMAB228, and SP142 vs. UMAB228, respectively. On the other hand, the univariate analysis of consensus cases indicated that the PD-L1 expression was significantly correlated with tobacco use (χ²=4.25, P=0.04).

Conclusions

The analytical comparison showed moderate concordance between SP142, SP263 and UMAB228, whereas SP263 exhibited higher overall positive rate. Moreover, PD-L1 positive rate was significantly higher in patients with smoking history, which might help in identifying patients who would benefit from PD-1/PD-L1 checkpoint inhibitors.

Association of PD-L1 Expression with Tumor-Infiltrating Immune Cells and Mutation Burden in High-Grade Neuroendocrine Carcinoma of the Lung

INTRODUCTION

The immune microenvironment of high-grade neuroendocrine carcinoma of the lung, including programmed death ligand 1 (PD-L1) expression, has not been well characterized.

METHODS

On the basis of immunohistochemistry (IHC) results, PD-L1 expression on tumor cells (TCs) and tumor-infiltrating immune cells (ICs) was scored as follows: TC0 and IC0 were defined as PD-L1 expression less than 1%, TC1 and IC1 as at least 1% but less than 10%, TC2 and IC2 as 10% or more but less than 50%, and TC3 and IC3 as 50% or more. Phosphatase and tensin homolog (PTEN) IHC was scored as either lost or retained expression. The Ion AmpliSeq Comprehensive Cancer Panel (ThermoFisher Scientific, Waltham, MA) was used to identify mutations in all coding exons of 409 cancer-related genes.

RESULTS

A total of 192 patients with large cell neuroendocrine carcinoma (LCNEC) (n = 72) and SCLC (n = 120) were studied. The prevalence of PD-L1 expression on TCs was 15.1% (29 of 192). IC infiltration and PD-L1 expression on ICs were observed in 34.4% of patients (66 of 192) and 31.3% of patients (60 of 192), respectively. The prevalence of IC infiltration and PD-L1 expression on IC were more strongly correlated with LCNEC than with SCLC (57.6% versus 23.3%, p < 0.01; 45.8% versus 22.5%, p < 0.01) and high nonsynonymous mutations (p = 0.05 and .04). PTEN loss was found in 9.5% of patients (18 of 189) and showed no correlation with PD-L1 expression. Progression-free survival was better in patients with IC infiltration than in those without IC infiltration (median 11.3 versus 6.8 months [p < 0.01]) and in patients with PD-L1 expression of IC1/2/3 than in those with expression of IC0 (median 11.3 versus 7.0 months [p = 0.03]).

CONCLUSION

These findings suggest that the PD-1/PD-L1 pathway is activated in the microenvironment of pulmonary high-grade neuroendocrine carcinoma and correlated with a higher mutation burden.

Association between PD-L1 expression and driver gene status in non-small-cell lung cancer: a meta-analysis

OBJECTIVE

To assess the association between PD-L1 expression and driver gene mutations in patients with non-small-cell lung cancer (NSCLC).

METHOD

We performed a meta-analysis of 26 studies (7541 patients) which were published from 2015 to 2017. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated to describe the correlation. Subgroup analysis was performed based on population characteristics, types of PD-L1 antibodies and quality of individual studies.

RESULTS

A lower frequency of PD-L1 positivity was observed in NSCLCs harboring EGFR mutation (OR: 0.64, 95% CI, 0.45-0.91, p = 0.014). A negative correlation was also found at 1% (OR: 0.35, 95% CI, 0.22-0.55, p = 0.000) and 50% (OR: 0.33, 95% CI, 0.14-0.81, p = 0.015) cutoff for PD-L1 positive, elderly age group (OR: 0.56, 95% CI, 0.35-0.89, p = 0.013), female dominant group (OR: 0.55, 95% CI, 0.29-0.94, p = 0.030) and smoker dominant group (OR: 0.52, 95% CI, 0.29-0.96, p = 0.035). No significant differences in PD-L1 expression were observed among patients with different ALK, BRAF, HER2, PIK3CA status and MET expression level. Higher level of PD-L1 was found in tumors with KRAS mutation (OR: 1.45, 95% CI, 1.18-1.80, p = 0.001). PD-L1 expression level was not significantly different between triple (EGFR/ALK/KRAS) wild type NSCLCs and those with EGFR/ALK/KRAS mutation.

CONCLUSIONS

PD-L1 expression in EGFR mutated NSCLCs were lower than those in EGFR wild type NSCLCs, while tumors with KRAS mutation showed higher levels of PD-L1.

Prognostic value of PD-L1 expression in combination with CD8+ TILs density in patients with surgically resected non-small cell lung cancer

To investigate the prognostic value of PD-L1 expression combined with CD8+ TILs density in patients with resected NSCLC and correlations with clinicopathological features. We retrospectively enrolled 178 patients with resected NSCLC from 2011 to 2015. All surgical primary and 58 matched metastatic lymph node specimens were tested for PD-L1, CD8+ TILs, and oncogenic alterations. PD-L1+ was detected in 71 (39.9%) and CD8high TILs in 74 (41.6%) cases. Smoking, SqCC, and EGFR- were associated with both PD-L1+ and CD8high TILs. Patients with CD8high TILs had longer OS (P = 0.012). PD-L1- was significantly associated with longer OS in patients with oncogenic alterations (P = 0.047). By multivariate analysis, CD8high TILs (HR = 0.411; 95% CI, 0.177-0.954; P = 0.038), rather than PD-L1, was the independent predictive factor for OS. The longest and shortest OS were achieved in patients with PD-L1+ /CD8high and PD-L1+ /CD8low , respectively (P = 0.025). Inconsistent PD-L1 expression levels were observed in 23 of 58 (39.7%) patients with primary and matched metastatic lymph node specimens. Of them, CD8high TILs was significantly associated with longer OS in patients with metastatic lymph nodes and/or consistent PD-L1 expression (P = 0.017 and 0.049, respectively). The combination of PD-L1 and CD8+ TILs density, instead of PD-L1 alone, suggested impressive prognostic values in NSCLC patients. Less than half of patients with resected NSCLC experienced inconsistent PD-L1 expression between primary and metastatic lesions. The level of PD-L1 expression in advanced NSCLC needs to be evaluated more comprehensively.

Aberrant status and clinicopathologic characteristic associations of 11 target genes in 1,321 Chinese patients with lung adenocarcinoma

Background

The aberrant status of target genes and their associations with clinicopathologic characteristics are still unclear in primary lung adenocarcinoma.

Methods

The common mutations and translocations of nine target genes were evaluated in 1,247 specimens of surgically-resected primary lung adenocarcinoma. Immunohistochemistry was used to analyze the expressions of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) in 731 specimens. The frequency of the aberrations and their associations with clinicopathologic characteristics were analyzed.

Results

Overall, 952 (76.3%) of 1,247 patients harbored at least one target mutation or translocation: epidermal growth factor receptor (EGFR) (729, 58.5%), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) (83, 6.7%), human epidermal growth factor receptor 2 (HER2) (82, 6.6%), anaplastic lymphoma kinase (ALK) (23, 1.8%), phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA) (20, 1.6%), Ret proto-oncogene RET (15, 1.2%), ROS proto-oncogene 1 receptor tyrosine kinase (ROS1) (12, 1.0%), B-raf proto-oncogene (BRAF) (9, 0.7%), neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS) (3, 0.2%). Fourteen (1.9%) of 731 patients were PD-1 positive and 95 (13.0%) were PD-L1 positive in tumor cells. In men and smokers, there were more frequent KRAS mutations (both P<0.001) and PD-L1 positive tumors (P<0.001, P=0.005, respectively), and less frequent EGFR mutations (P=0.049, <0.001, respectively). In ground-glass opacity (GGO) or ground-glass nodules (GGN), there were more HER2 (P=0.033) but less EGFR (P=0.025) and PIK3CA mutations (P=0.012), and ALK translocations (P=0.014). EGFR (P<0.001), KRAS mutations (P=0.004) and PD-L1 positive tumors (P=0.046) were more frequent in older patients, while HER2 (P<0.001), ALK (P=0.005) and ROS1 aberrations (P=0.044) were less frequent. Invasive mucinous adenocarcinoma was significantly associated with KRAS and ALK aberrations (both P<0.001), while solid predominant adenocarcinoma was associated with ROS1 translocations (P=0.036) and PD-L1 expression (P<0.001). KRAS, HER2, and ALK aberrations were scarce in patients with EGFR mutations (all P<0.001), while PD-L1 positive tumors positively correlated with ALK translocations (P=0.031) and negatively correlated with HER2 mutations (P=0.019).

Conclusions

Most patients with primary lung adenocarcinoma harbored target gene aberrations. The frequency of each alteration differed in patients depending on clinicopathologic characteristics.

Prognostic value of PD -L1 expression in patients with primary solid tumors

Programmed death-ligand 1 (PD-L1) is thought to play a critical role in immune escape by cancer, but whether PD-L1 expression can influence prognosis of patients with solid tumors is controversial. Therefore, we meta-analyzed available data on whether PD-L1 expression correlates with overall survival (OS) in such patients. PubMed, EMBASE and other databases were systematically searched for cohort or case-control studies examining the possible correlation between PD-L1 expression and OS of patients with solid tumors. OS was compared between patients positive or negative for PD-L1 expression using scatter plots, and subgroup analyses were performed based on tumor type and patient characteristics. Data from 59 studies involving 20,004 patients with solid tumors were meta-analyzed. The median percentage of tumors positive for PD-L1 was 30.1%. OS was significantly lower in PD-L1-positive patients than in PD-L1-negative patients at 1 year (P = 0.039), 3 years (P < 0.001) and 5 years (P < 0.001). The risk ratios of OS (and associated 95% confidence intervals) were 2.02 (1.56-2.60) at 1 year, 1.57 (1.34-1.83) at 3 years and 1.43 (1.24-1.64) at 5 years. Similar results were obtained in subgroup analyses based on patient ethnicity or tumor type. The available evidence suggests that PD-L1 expression negatively affects the prognosis of patients with solid tumors. PD-L1 might serve as an efficient prognostic indicator in solid tumor and may represent the important new therapeutic target.

Implications of KRAS mutations in acquired resistance to treatment in NSCLC

Rationale

KRAS is the most common and, simultaneously, the most ambiguous oncogene implicated in human cancer. Despite KRAS mutations were identified in Non Small Cell Lung Cancers (NSCLCs) more than 20 years ago, selective and specific inhibitors aimed at directly abrogating KRAS activity are not yet available. Nevertheless, many therapeutic approaches have been developed potentially useful to treat NSCLC patients mutated for KRAS and refractory to both standard chemotherapy and targeted therapies.

The focus of this review will be to provide an overview of the network related to the intricate molecular KRAS pathways, stressing on preclinical and clinical studies that investigate the predictive value of KRAS mutations in NSCLC patients.

Materials and Methods

A bibliographic search of the Medline database was conducted for articles published in English, with the keywords KRAS, KRAS mutations in non-small cell lung cancer, KRAS and tumorigenesis, KRAS and TKIs, KRAS and chemotherapy, KRAS and monoclonal antibody, KRAS and immunotherapy, KRAS and drugs, KRAS and drug resistance.

Clinical significance of PD-L1 and PD-L2 copy number gains in non-small-cell lung cancer

New reliable biomarkers are needed to predict the response to immune checkpoint inhibitors against programmed death-1 (PD-1) and its ligand (PD-L1), because PD-L1 expression on tumor cells has limited power for selecting patients who may benefit from such therapy. Here we investigated the significance of PD-L1 and PD-L2 gene copy number gains using fluorescence in situ hybridization as well as PD-L1 and PD-L2 expression in 654 patients with resected non-small-cell lung cancer. The prevalence of PD-L1 amplification and polysomy was 3.1% and 13.2%, respectively. The PD-L1 gene copy number status was in agreement with both the PD-L2 and Janus kinase 2 gene copy number statuses. PD-L1 and PD-L2 expression was observed in 30.7% and 13.1%, respectively. Both PD-L1 copy number gains and expression were associated with smoking-related tumors. Tumor cells with PD-L1 genomic gains exhibited significantly higher levels of PD-L1 expression than those without, but PD-L2 copy number gains were not related to PD-L2 augmentation. PD-L1 gene amplification and polysomy were independently associated with PD-L1 expression, with high immune infiltrates and EGFR expression in a multivariate logistic regression model. Comparative analysis between primary tumors and synchronous regional lymph node metastases revealed that the PD-L1 gene copy number alterations were highly consistent and reproducible compared with the PD-L1 expression. Both PD-L1 amplification and level of protein expression were predictors of poor survival using Cox univariate analyses. Therefore, we conclude that an increase in PD-L1 gene copy number can be a feasible alternative biomarker for predicting response to anti-PD-1/PD-L1 therapy.

CD274/PD-L1 gene amplification and PD-L1 protein expression are common events in squamous cell carcinoma of the oral cavity

Immunomodulatory therapies, targeting the immune checkpoint receptor-ligand complex PD-1/PD-L1 have shown promising results in early phase clinical trials in solid malignancies, including carcinomas of the head and neck. In this context, PD-L1 protein expression has been proposed as a potentially valuable predictive marker. In the present study, expression of PD-L1 and PD-1 was evaluated by immunohistochemistry in 80 patients with predominantly HPV-negative oral squamous cell carcinomas and associated nodal metastasis. In addition, CD274/PD-L1 gene copy number status was assessed by fluorescence in situ hybridization analysis. PD-L1 expression was detected in 36/80 (45%) cases and concordance of PD-L1 expression in primary tumor and corresponding nodal metastasis was present in only 20/28 (72%) cases. PD-1 expression was found in tumor-infiltrating lymphocytes (TILs) but not in tumor cells. CD274/PD-L1 gene amplification was detected in 19% of cases, with high level PD-L1 amplification present in 12/80 (15%), and low level amplification in 3/80 (4%). Interestingly, CD274/PD-L1 gene amplification was associated with positive PD-L1 immunostaining in only 73% of cases. PD-L1 copy number status was concordant in primary tumor and associated metastases. Clinically, PD-L1 tumor immunopositivity was associated with a higher risk for nodal metastasis at diagnosis, overall tumor related death und recurrence. Based on our findings we propose to include PD-L1 copy number status in addition to protein status in screening programs for future clinical trials with immunotherapeutic strategies targeting the PD-1/PD-L1 axis.

YAP regulates PD-L1 expression in human NSCLC cells

Programmed death-ligand 1 (PD-L1) is a membrane protein on tumor cells that binds to the PD-1 receptor expressed on immune cells, leading to the immune escape of tumor cells. Yes-associated protein (YAP) is a main effector of the Hippo/YAP signaling pathway, which plays important roles in cancer development. Here we show that YAP regulates PD-L1 expression in human non-small cell lung cancer (NSCLC) cells. First, we investigated YAP and PD-L1 expression at the protein level in 142 NSCLC samples and 15 normal lung samples. In tumor tissue, immunohistochemistry showed positive staining for YAP and PD-L1, which correlated significantly (n = 142, r = 0.514, P < 0.001). Second, in cell lines that express high levels of PD-L1 (H460, SKLU-1, and H1299), the ratio of p-YAP/YAP was lower and GTIIC reporter activity of the Hippo pathway was higher than those in three cell lines expressing low levels of PD-L1 (A549, H2030, and PC9) (P < 0.05). Third, in the same three cell lines, inhibition of YAP by two small interfering RNAs (siRNAs) decreased the mRNA and protein level of PD-L1 (P < 0.05). Fourth, forced overexpression of the YAP gene rescued the PD-L1 mRNA and protein level after siRNA knockdown targeting 3′UTR of the endogenous YAP gene. Finally, chromatin immunoprecipitation (ChIP) assays using a YAP-specific monoclonal antibody resulted in the precipitation of PD-L1 enhancer region encompassing two putative TEAD binding sites. Our results indicate that YAP regulates the transcription of PD-L1 in NSCLC.

Advances in T-cell checkpoint immunotherapy for head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) has been found to be a complex group of malignancies characterized by their profound immunosuppression and high aggressiveness. In most cases of advanced HNSCC, treatment fails to obtain total cancer cure. Efforts are needed to develop new therapeutic approaches to improve HNSCC outcomes. In this light, T-cells "immune checkpoint" has attracted much attention in cancer immunotherapy. It has been broadly accepted that inhibitory T-cell immune checkpoints contribute to tumor immune escape through negative immune regulatory signals (cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4], programmed cell death 1 [PD-1], B7-H3, and B7-H4, etc). Current data suggest that PD-1 and CTLA-4 receptors can inhibit T-cell receptors and T-cell proliferation. Blockade of PD-1/PD-L1 and/or CTLA-4/CD28 pathways has shown promising tumor outcomes in clinical trials for advanced solid tumors like melanoma, renal cell cancer, and non-small cell lung cancer. The present review attempts to explore what is known about PD-1/PD-L1 and CTLA-4/CD28 pathways with a focus on HNSCC. We further discuss how these pathways can be manipulated with therapeutic intent.

Comparison of Four PD-L1 Immunohistochemical Assays in Lung Cancer

INTRODUCTION

Four different programmed death ligand 1 immunohistochemical assays are approved or in development as companion or complementary diagnostics to different immunotherapeutic agents in lung carcinoma. We sought to determine whether these assays are technically equivalent and whether one antibody can be used on an alternate staining platform.

METHODS

Serial sections of tissue microarrays constructed from 368 cases of resected lung cancer were stained for 22C3 and 28-8 on the Dako Link 48 platform (Dako, Carpinteria, Ca) and for SP142 and SP263 on the Ventana Benchmark Ultra platform (Ventana Medical Systems, Tucson, AZ) strictly as per product insert. A protocol was developed to use the 22C3 antibody on the Ventana Benchmark Ultra platform.

RESULTS

Differences in mean tumor cell and immune cell staining were observed between the four assays (p < 0.001). Differences between 22C3 and 28-8 were not statistically significant. Concordance of tumor cell scores was good (intraclass correlation coefficient [ICC] = 0.674), particularly when SP142 was excluded as an outlier (ICC = 0.755). The highest concordance was seen between 22C3 and 28-8 (ICC = 0.812). Concordance was poor for immune cell staining (ICC = 0.212). When dichotomized according to clinically relevant cutoffs, pairwise comparisons showed poor to moderate concordance (κ = 0.196-0.578), with positive percent agreement ranging from 15.1% to 90.0%. The 22C3 antibody performed comparably on the Dako Link 48 platform and the alternate Ventana Benchmark Ultra platform (ICC = 0.921, κ = 0.897).

CONCLUSIONS

Concordance between the four programmed death ligand 1 immunohistochemical assays when performed and scored as intended show that apart from 28-8 and 22C3, they cannot be used interchangeably in clinical practice. A protocol was successfully developed to use 22C3 on an alternate platform, which may help to overcome some barriers to implementation.

Immune checkpoint inhibitors in epidermal growth factor receptor mutant non-small cell lung cancer: Current controversies and future directions

Major advances with the development of epidermal growth factor receptor tyrosine kinase inhibitors and immune check-point inhibitors have ushered in a new era in lung cancer therapy. Whilst pre-clinical studies suggest EGFR-driven NSCLC inhibit antitumor immunity through the activation of the PD-1/PD-L1 pathway, epidemiology studies suggest EGFR mutant NSCLC are more likely to have decreased PD-L1 expression. The superiority of single agent PD-1/PD-L1 inhibitors over docetaxel in pre-treated EGFR mutant NSCLC appears to be moderated. Several mechanisms for a poor response to immune checkpoint have been proposed including a lower tumor mutation burden, and an uninflamed and immunosuppressive tumor microenvironment. Predictive biomarkers to PD-1/PD-L1 inhibitors sensitivity in patients with EGFR mutations are required. The role of EGFR TKI in combination with an immune checkpoint inhibitor is currently being investigated intensively in multiple clinical trials and outcomes from these trials are immature and the optimal sequence, schedule and dosing remains to be determined. A careful evaluation will be required in view of the increased toxicities reported in some of the early studies of combination therapy.

Programmed Death-Ligand 1 Expression in a Large Cohort of Pediatric Patients With Solid Tumor and Association With Clinicopathologic Features in Neuroblastoma

Purpose

Programmed death-ligand 1 (PD-L1) expression represents a potential predictive biomarker of immune checkpoint blockade response. However, literature about the prevalence of PD-L1 expression in the pediatric cancer setting is discordant.

Methods

PD-L1 expression was analyzed using immunohistochemistry in 500 pediatric tumors (including neuroblastoma, sarcomas, and brain cancers). Tumors with ≥ 1% cells showing PD-L1 membrane staining of any intensity were scored as positive. Positive cases were further characterized, with cases with weak intensity PD-L1 staining reported as having low PD-L1 expression and cases with a moderate or strong intensity of staining considered to have high PD-L1 expression.

Results

PD-L1–positive staining was identified in 13% of cases, whereas high PD-L1 expression was found in 3% of cases. Neuroblastoma (n = 254) showed PD-L1 expression of any intensity in 18.9% of cases and was associated with longer overall survival ( P = .045). However, high PD-L1 expression in neuroblastoma (3.1%) was significantly associated with an increased risk of relapse ( P = .002). Positive PD-L1 staining was observed more frequently in low- and intermediate-risk patients ( P = .037) and in cases lacking MYCN amplification ( P = .002).

Conclusion

In summary, high PD-L1 expression in patients with neuroblastoma may represent an unfavorable prognostic factor associated with a higher risk of cancer relapse. This work proposes PD-L1 immunohistochemical assessment as a novel parameter for identifying patients with an increased likelihood of cancer recurrence.

The Significance of the PD-L1 Expression in Non-Small-Cell Lung Cancer: Trenchant Double Swords as Predictive and Prognostic Markers

Lung cancer is the leading cause of death due to cancer worldwide. Surgery, chemotherapy, and radiotherapy have been the standard treatment for lung cancer, and targeted molecular therapy has greatly improved the clinical course of patients with non-small-cell lung cancer (NSCLC) harboring driver mutations, such as in epidermal growth factor receptor and anaplastic lymphoma kinase genes. Despite advances in such therapies, the prognosis of patients with NSCLC without driver oncogene mutations remains poor. Immunotherapy targeting programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) has recently been shown to improve the survival in advanced NSCLC. The PD-L1 expression on the surface of tumor cells has emerged as a potential biomarker for predicting responses to immunotherapy and prognosis after surgery in NSCLC. However, the utility of PD-L1 expression as a predictive and prognostic biomarker remains controversial because of the existence of various PD-L1 antibodies, scoring systems, and positivity cutoffs. In this review, we summarize the data from representative clinical trials of PD-1/PD-L1 immune checkpoint inhibitors in NSCLC and previous reports on the association between PD-L1 expression and clinical outcomes in patients with NSCLC. Furthermore, we discuss the future perspectives of immunotherapy and immune checkpoint factors.

Prognostic value of PD-L1 overexpression for pancreatic cancer: evidence from a meta-analysis

Programmed death-ligand 1 (PD-L1) is an immune checkpoint that is often activated in cancer and plays a pivotal role in the initiation and progression of cancer. However, the clinicopathologic significance and prognostic value of PD-L1 in pancreatic cancer (PC) remains controversial. In this study, we conducted a meta-analysis to retrospectively evaluate the relationship between PD-L1 and PC. PubMed and other databases were searched for the clinical studies published up to March 21, 2017, to be included in the meta-analysis. Hazard ratios and their 95% CIs were calculated. Risk ratios (RRs) were extracted to assess the correlations between the clinicopathologic parameters and PD-L1 expression. Ten studies including 1,058 patients were included in the meta-analysis. The pooled results indicated that positive PD-L1 expression was correlated with a poor overall survival outcome in PC patients (hazard ratio =1.76, 95% CI: 1.43–2.17, P<0.00001). Interestingly, high PD-L1 expression was correlated with poor pathologic differentiation (RR =1.57, 95% CI: 1.25–1.98, P=0.0001) and neural invasion (RR =1.30, 95% CI: 1.03–1.64, P=0.03). However, there were no significant correlations between PD-L1 expression and other clinicopathologic characteristics. In summary, our meta-analysis implied that PD-L1 could serve as a negative predictor for the overall survival of PC patients, and high expression of PD-L1 was correlated with poor differentiation and neural invasion, indicating that anti-PD-L1 treatments should be evaluated in PC patients, especially in those who exhibit these two characteristics.

The correlation between programmed death-ligand 1 expression and driver gene mutations in NSCLC

OBJECTIVES

This study aimed to evaluate the correlation between positive PD-L1 expression and driver gene mutations in NSCLC and to seek preliminary evidence in favor of the strategy of PD-L1 inhibitors plus targeted agents.

RESULTS

The overall analyses revealed that positive PD-L1 expression had a significant relationship with KRAS status (RR = 1.26; 95% CI, 1.06-1.50, P = 0.010), but no correlation with clinical characteristics (gender, smoking status, histological types), driver gene status (EGFR, ALK) and overall survival (OS): male versus female (RR = 1.16; 95% CI, 0.95-1.42; P = 0.15), never smoking versus former/current smoking (RR = 0.79; 95% CI, 0.56-1.11; P = 0.17), adenocarcinoma versus non-adenocarcinoma (RR = 0.94; 95% CI, 0.63-1.41; P = 0.77), EGFR mutation versus EGFR wild type (RR = 0.74; 95% CI, 0.52-1.06; P = 0.10), ALK positive versus ALK negative (RR = 1.02; 95% CI, 0.75-1.38; P = 0.91), OS of positive PD-L1 expression versus that of negative PD-L1 expression (HR = 1.31, 95% CI, 0.90-1.90; P = 0.15), respectively. Noteworthily, subgroup analyses exhibited that in Chinese cohort studies, positive PD-L1 expression was significantly correlated with OS (HR = 1.75, 95% CI, 1.36-2.24, P < 0.0001); and in the studies using PD-L1 monoclonal antibodies (McAbs), positive PD-L1 expression was significantly correlated with KRAS mutation (RR = 1.32, 95% CI, 1.06-1.65, P = 0.01) and EGFR mutation (RR = 0.51, 95% CI, 0.28-0.93, P = 0.03).

MATERIALS AND METHODS

After thoroughly searching PubMed, EMBASE and Cochrane Library databases, 11 relevant studies incorporating 3128 cases were identified. The pooled data were analyzed via Review manager 5.3 software.

CONCLUSIONS

PD-L1 inhibitors probably was a potential promising option to manage advanced NSCLC harboring KRAS mutation.

PD-L1 is a Prognostic Biomarker in Resected NSCLC Patients with Moderate/high Smoking History and Elevated Serum SCCA Level

Programmed cell death-1 (PD-1) -targeted immunotherapy has become a promising treatment paradigm for patients with advanced non-small cell lung cancer (NSCLC). Clinical responses to checkpoint inhibition therapy in NSCLC have been associated with programmed death-1 ligand 1 (PD-L1) expression. However, the association between the expression of PD-L1 and PD-L2 and the clinicopathological features and patient outcomes in NSCLC remain unclear. We retrospectively analyzed 364 patients (158 squamous cell carcinoma and 206 adenocarcinoma) who underwent complete resection between 2009 and 2012. Expression of PD-L1 and PD-L2 was determined by immunohistochemistry. Correlations between PD-L1/PD-L2 expression and the clinicopathological features and survival parameters were analyzed and prognostic factors were identified. PD-L1 expression was significantly associated with moderate/heavy smoking history and serum squamous cell carcinoma antigen (SCCA) levels. Multivariate analysis showed patients with high PD-L1 expression had significantly shorter disease free survival (DFS, HR 1.411, P = 0.025) and overall survival (OS, HR 1.659, P = 0.004) than those with low PD-L1 expression at a 50% cutoff value. No significant association was found between PD-L2 expression and patient postoperative survival. Further stratification analysis revealed that in patients with moderate/heavy smoking history, elevated serum SCCA level, and squamous cell carcinoma, PD-L1 expression was associated with significantly shorter DFS and OS. Therefore, PD-L1 expression was correlated with moderate/heavy smoking history and elevated serum SCCA level in NSCLC patients, and was an independently poor predictor of survival.

PD-L1 expression in lung cancer and its correlation with driver mutations: a meta-analysis

Although many studies have addressed the prognostic value of programmed cell death-ligand 1 (PD-L1) expression in lung cancer, the results remain controversial. A systematic search of the PubMed, EMBASE, and Cochrane Library databases was performed to identify the correlation between PD-L1 expression and driver mutations and overall survival (OS). This meta-analysis enrolled a total of 11,444 patients for 47 studies, and the pooled results showed that increased PD-L1 expression was associated with poor prognosis (HR = 1.40, 95% CI: 1.19-1.65, P < 0.001). In subgroup analysis stratified according to histology types, the pooled results demonstrated that increased PD-L1 expression was an unfavorable prognostic factor for non-small cell lung cancer (NSCLC) (HR = 1.26, 95% CI: 1.05-1.52, P = 0.01) and pulmonary lymphoepithelioma-like carcinoma (LELC) (HR = 3.04, 95% CI: 1.19-7.77, P = 0.02), rather than small cell lung cancer (SCLC) (HR = 0.62, 95% CI: 0.27-1.39, P = 0.24). The pooled ORs indicated that PD-L1 expression was associated with gender, smoking status, histology, differentiation, tumour size, lymph nodal metastasis, TNM stage and EGFR mutation. However, PD-L1 expression was not correlated with ALK rearrangement and KRAS mutations.

Programmed Death Ligand-1 (PD-L1) Expression in Either Tumor Cells or Tumor-Infiltrating Immune Cells Correlates With Solid and High-Grade Lung Adenocarcinomas

Context.—

Programmed death ligand-1 (PD-L1) expression in non–small cell lung carcinoma (NSCLC) is heterogeneous and known to be underestimated on small biopsies. Correlation of PD-L1 expression with clinicopathologic features may provide additional useful information. To our knowledge, the clinicopathologic features of NSCLC have not been reported for subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells.

Objective.—

To investigate the clinicopathologic characteristics of NSCLC subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells.

Design.—

PD-L1 immunohistochemistry with the SP142 clone was performed on whole-tissue sections and given semiquantitative scores (0/1/2/3) according to percent of PD-L1+ tumor cells (TCs) and percent tumor area with PD-L1+ tumor-infiltrating immune cells (ICs).

Results.—

Adenocarcinoma cases that were scored either TC 1/2/3 or IC 1/2/3 included most (22 of 34; 65%) high–histologic grade cases and most (25 of 36; 69%) solid subtype cases. Compared with the adenocarcinoma TC 0 and IC 0 subset, the TC 1/2/3 or IC 1/2/3 subset correlated with higher histologic grade (P = .005, χ2 test for trend) and solid subtype (P &lt; .001, Fisher exact test). Compared with the adenocarcinoma TC 0/1 or IC 0/1 subset, the TC 2/3 or IC 2/3 subset correlated with higher histologic grade (P = .002, χ2 test for trend), solid subtype (P &lt; .001, Fisher exact test), and higher smoking pack-years (P = .01, Mann-Whitney test).

Conclusions.—

Lung adenocarcinoma subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells correlated with high histologic grade, solid subtype, and high smoking pack-years.

Prognostic significance of PD-L1 expression and tumor infiltrating lymphocyte in surgically resectable non-small cell lung cancer

Programmed death ligand 1 (PD-L1) expression is a predictive biomarker of the success of PD-1/PD-L1 inhibitor therapy for patients with advanced non-small cell lung cancer (NSCLC) but its role as a prognostic marker for early stage resectable NSCLC remains unclear. Here, we studied PD-L1 expression and tumor infiltrating lymphocytes (TILs) in surgically resectable NSCLC and correlate the finding with clinicopathological features and patient outcomes. Total of 170 archival samples of resectable NSCLC were probed for PD-L1 expression using the clone 22C3 pharmDx kit. The PD-L1 expression was determined by the Tumor Proportion Score (TPS) and classified into TPS <1%, TPS 1 to 49% and TPS ≥50%. The scoring of TILs was from hematoxylin & eosin stained tissue sections using a system for standardized evaluation of TILs in breast cancer. PD-L1 expression was compared with clinical pathological characteristics and survival outcome. Expression of PD-L1 scores of TPS ≥50%, TPS 1 to 49% and TPS <1% were observed in 10.6%, 24.7% and 64.7% of the 170 archival samples, respectively. Positive PD-L1 expression was significantly higher in patients with squamous carcinoma, in those with higher TNM stage and with the presence of TILs. Neither the PD-L1 expression, TIL status, nor their combination was an independent prognosis biomarker of survival when the data was subjected to either univariate or multivariate analysis. The incidence of PDL1 expression appears to be lower in patient with early stage resectable lung cancer. PD-L1 expression and TILs are not prognostic indicators of survival outcome in this population.

Clinicopathologic implications of the miR-197/PD-L1 axis in oral squamous cell carcinoma

Immune escape of a tumor from tumor-infiltrating lymphocytes (TILs) is induced by PD-L1, which is suppressed by miR-197. We investigated the clinicopathologic implications of the miR-197/PD-L1 axis and its effects on TILs and the clinicopathologic features of oral squamous cell carcinoma (OSCC). We used RT-PCR and immunohistochemistry in 68 OSCC patients to analyze the correlations between tumoral expression of miR-197 and PD-L1 and the degree of tumoral invasion by TILs (CD3+, CD4+, CD8+, PD-1+, FoxP3+, and CD20+ lymphocytes). PD-L1 levels correlated inversely with miR-197 but correlated positively with TILs. The aggressive features of OSCC, including high stage, angiolymphatic invasion, perineural invasion, and death, were associated with TIL depletion. High T stage (T4) tumors also had low PD-L1 but had high miR-197 expression. In a univariate survival analysis of the full cohort, high miR-197 was associated with poor overall survival, whereas high PD-L1 expression (2+) associated with good overall survival. In a multivariate analysis stratified based on miR-197 (median), high PD-L1 expression (2+) was an independent favorable prognostic factor for overall survival (P = 0.040) in the miR-197^high subgroup but not the miR-197^low subgroup. These findings may have clinicopathologic implications for the miR-197/PD-L1 axis and TILs in OSCC.

Expression of PD-L1 and other immunotherapeutic targets in thymic epithelial tumors

Introduction

The thymus is a critical organ for the development of the adaptive immune system and thymic epithelial tumors (TETs; thymomas and thymic carcinomas) are often associated with auto-immune paraneoplastic conditions. However, the immunobiology of TETs is not well described. An evaluation of the tumor microenvironment, with particular focus on expression of immunotherapeutic targets, may facilitate and prioritize development of immunotherapy strategies for patients with TETs.

Methods

Tumor tissues from 23 patients with WHO Type B2/B3 thymoma (n = 12) and thymic carcinoma (n = 11) were identified and clinical outcomes were annotated. The expression of membranous PD-L1 on tumor cells, CD3+ and CD8+ tumor infiltrating lymphocytes (TILs), co-stimulatory (CD137, GITR, ICOS), and co-inhibitory immune checkpoint molecules (PD-1, CTLA-4, TIM-3) were assessed semi-quantitatively using immunohistochemistry.

Results

PD-L1 positivity (≥ 25% of tumor membrane expression) was frequent in TETs (15/23, 65%), more common in thymomas compared to thymic carcinomas (p<0.01), and was associated with longer overall survival (p = 0.02). TIM-3 and GITR were expressed in all TETs, including 18/23 and 12/23 with at least moderate/high expression, respectively. Moderate/high CD137 expression correlated with CD8+ (p = 0.01) and moderate/high GITR expression co-associated with PD-1 (p = 0.043).

Conclusions

TETs are characterized by frequent PD-L1 expression and PD-L1 is associated with improved survival, suggesting PD-L1 signaling may be biologically important in TETs. Robust expression of markers of immune activation and immunotherapeutic target molecules in TETs emphasizes the potential for development of anti-PD-1/PD-L1 therapies.

A systematic and genome-wide correlation meta-analysis of PD-L1 expression and targetable NSCLC driver genes

BACKGROUND

Studies have shown that the ligand of programmed cell death protein 1 (B7-H1, CD274 or PD-L1) is related to lung cancer driver genes. Although studies have examined the association between lung cancer driver gene mutations or expression and PD-L1 expression, the present studies have not been mined the correlation systematically and genome-widely.

METHODS

All relevant published PD-L1 articles with driver genes data and the RNA-seq dataset from The Cancer Genome Atlas (TCGA) were analyzed. We performed meta-analysis for data included in the selected literature, and then independently explored the correlation between genes by co-expression analysis of RNA-seq data in the TCGA database.

RESULTS

A sum of 9,934 lung cancer cases were collected from 34 published studies. Higher PD-L1 expression was associated with wild-type epidermal growth factor receptor (EGFR) [odds ratio (OR): 0.68, 95% confidence interval (CI): 0.48-0.96, P=0.03], Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation (OR: 1.27, 95% CI: 1.02-1.58, P=0.03) or non-adenocarcinoma histology (OR: 0.68, 95% CI: 0.47-0.98, P=0.04). In addition, our analysis from TCGA data indicated that, compared with lung adenocarcinoma, the expression of PD-L1 was significantly higher than that of squamous cell carcinoma patients (P=0.023). The expression of targetable driver genes showed no correlations with PD-L1 expression in non-small cell lung cancer (NSCLC).

CONCLUSIONS

Our results suggest the presence of EGFR wild-type, KRAS gene mutations or squamous cell carcinoma were associated with high PD-L1expression, which provides potential benefited population for the administration of PD-1/PD-L1 blockade in human lung cancer.

Expression and clinical association of programmed cell death-1, programmed death-ligand-1 and CD8+ lymphocytes in primary sarcomas is subtype dependent

In order to explore the potential of immune checkpoint blockade in sarcoma, we investigated expression and clinical relevance of programmed cell death-1 (PD-1), programmed death ligand-1 (PD-L1) and CD8 in tumors of 208 sarcoma patients. Primary untreated osteosarcoma (n = 46), Ewing sarcoma (n = 32), alveolar rhabdomyosarcoma (n = 20), embryonal rhabdomyosarcoma (n = 77), synovial sarcoma (n = 22) and desmoplastic small round cell tumors (DSRCT) (n = 11) were examined immunohistochemically. PD-L1 expression was predominantly detected in alveolar and embryonal rhabdomyosarcomas (15% and 16%, respectively). In the alveolar subtype PD-L1 expression was associated with better overall, event-free and metastases-free survival. PD-1 expression on lymphocytes was predominantly seen in synovial sarcomas (18%). High levels of CD8+ lymphocytes were predominantly detected in osteosarcomas (35%) and associated with worse event-free survival in synovial sarcomas. Ewing sarcoma and DSRCTs showed PD-1 on tumor cells instead of on tumor infiltrating lymphocytes. Overall, expression and clinical associations were found to be subtype dependent. For the first time PD-1 expression on Ewing sarcoma (19%) and DSRCT (82%) tumor cells was described.

A Four-Factor Immunoscore System That Predicts Clinical Outcome for Stage II/III Gastric Cancer

The American Joint Committee on Cancer (AJCC) staging system is insufficiently prognostic for operable gastric cancer patients; therefore, complementary factors are under intense investigation. Although the focus is on immune markers, the prognostic impact of a single immune factor is minimal, due to complex antitumor immune responses. A more comprehensive evaluation may engender more accurate predictions. We analyzed immune factors by immunohistochemical staining in two independent cohorts. The association with patients' survival was analyzed by the Kaplan-Meier method. Our immunoscore system was constructed using Cox proportional hazard analysis. PD-L1⁺ immune cells (IC), PD-L1⁺ tumor cells (TC), PD-1^hi, and CD8^More were found among 33.33%, 31.37%, 33.33%, and 49%, respectively, of patients from the discovery cohort, and 41.74%, 17.4%, 38.26%, and 30.43% from the validation cohort. PD-L1⁺ ICs and PD-1^hi ICs correlated with poorer overall survival (OS), but PD-L1⁺ TCs correlated with better OS and clinical outcomes and infiltration of more CD8⁺ T cells. These four factors were independently prognostic after tumor/lymph nodes/metastasis (TNM) stage adjustment. An immunoscore system based on hazard ratios of the four factors further separated gastric cancer patients with similar TNM staging into low-, medium-, or high-risk groups, with significantly different survival. Our prognostic model yielded an area under the receiver operating characteristic curve (AUC) of 0.856 for prediction of mortality at 5 years, superior to that of TNM staging (AUC of 0.676). Thus, this more comprehensive immunoscore system can provide more accurate prognoses and is an essential complement to the AJCC staging system for operable gastric cancer patients. Cancer Immunol Res; 5(7); 524-34. ©2017 AACR.

PD-L1 and intratumoral immune response in breast cancer

Purpose

PD-L1 is thought to play an important role in the antitumor immune response. In this study, we investigated the expression of PD-L1 within breast tumor subsets to better define its prognostic significance.

Methods

Immunohistochemistry was performed to determine PD-L1 tumor cell expression and to enumerate CD8, CD4 and CD68 tumor-infiltrating leucocytes (TIL) in a cohort of 443 breast cancers categorized by molecular subtype.

Results

Across the entire cohort, PD-L1 tumor cell expression was observed in 73/443 (16.5%) cases and associated with known indicators of poor prognosis, including low patient age, high tumor grade, ER/PR negative status, but not with outcome. However, in the Triple Negative breast cancer subset PD-L1 was associated with better recurrence free survival (RFS) especially within the Basal-like subset (Hazard ratio = 0.39, 95% CI = 0.22 - 0.86, p = 0.018). Combined PD-L1/epithelial CD8 positive status was also strongly associated with better RFS and OS (Hazard ratio = 0.12, 95% CI = 0.10 - 0.71, p = 0.010 and Hazard ratio = 0.11, 95% CI = 0.11 - 0.68, p = 0.006 respectively) in the Basal-like subgroup.

Conclusions

PD-L1 expression is associated with better patient survival in Basal-like breast cancer.

PD-L1 protein expression assessed by immunohistochemistry is neither prognostic nor predictive of benefit from adjuvant chemotherapy in resected non-small cell lung cancer

Background

The expression of programmed death (PD) ligand 1 (PD-L1) protein expression assessed by immunohistochemistry (IHC) has been correlated with response and survival benefit from anti-PD-1/PD-L1 immune checkpoint inhibitor therapies in advanced non-small cell lung carcinoma (NSCLC). The efficacy of several agents appears correlated with PD-L1 expression. It remains controversial whether PD-L1 is prognostic in NSCLC. We assessed the prognostic value of PD-L1 IHC and its predictive role for adjuvant chemotherapy in early stage NSCLC.

Patients and methods

Tumor sections from three pivotal adjuvant chemotherapy trials (IALT, JBR.10, CALGB 9633) using the E1L3N antibody were studied in this pooled analysis. PD-L1 staining intensity and percentage in both tumor cells (TCs) and immune cells (ICs) were scored by two pathologists. The average or consensus PD-L1 expression levels across intensities and/or percent cells stained were correlated with clinicopathological and molecular features, patient survivals and potential benefit of adjuvant chemotherapy.

Results

Results from 982 patients were available for analysis. Considering staining at any intensities for overall PD-L1 expression, 314 (32.0%), 204 (20.8%) and 141 (14.3%) tumor samples were positive for PD-L1 staining on TCs using cut-offs at ≥1%, ≥10% and ≥25%, respectively. For PD-L1 expressing ICs, 380 (38.7%), 308 (31.4%) and 148 (15.1%) were positive at ≥ 1%, ≥10% and 25% cut-offs, respectively. Positive PD-L1 was correlated with squamous histology, intense lymphocytic infiltrate, and KRAS but not with TP53 mutation. EGFR mutated tumors showed statistically non-significant lower PD-L1 expression. PD-L1 expression was neither prognostic with these cut-offs nor other exploratory cut-offs, nor were predictive for survival benefit from adjuvant chemotherapy.

Conclusions

PD-L1 IHC is not a prognostic factor in early stage NSCLC patients. It is also not predictive for adjuvant chemotherapy benefit in these patients.

PD-L1 expression and its relationship with oncogenic drivers in non-small cell lung cancer (NSCLC)

In order to explore the potential patient population who could benefit from anti PD-1/PD-L1 mono or combination therapies, this study aimed to profile a panel of immunotherapy related biomarkers (PD-1, PD-L1, CTLA-4 and CD8) and targeted therapy biomarkers (EGFR, KRAS, ALK, ROS1 and MET) in NSCLC.Tumor samples from 297 NSCLC patients, including 156 adenocarcinomas (AD) and 129 squamous cell carcinomas (SCC), were analyzed using immunohistochemistry, immunofluorescence, sequencing and fluorescence in situ hybridization.43.1% of NSCLC patients had PD-L1 positive staining on ≥ 5% tumor cells (TC). Furthermore, dual color immunofluorescence revealed that the majority of PD-L1/CD8 dual positive tumor infiltrating lymphocytes (TIL) had infiltrated into the tumor core. Finally, combined analysis of all eight biomarkers showed that tumor PD-L1 positivity overlapped with known alterations in NSCLC oncogenic tumor drivers in 26% of SCC and 76% of AD samples.Our illustration of the eight biomarkers' overlap provides an intuitive overview of NSCLC for personalized therapeutic strategies using anti-PD-1/PD-L1 immune therapies, either as single agents, or in combination with targeted therapies. For the first time, we also report that PD-L1 and CD8 dual positive TILs are predominantly located within the tumor core.

Intra- and Interobserver Reproducibility Assessment of PD-L1 Biomarker in Non-Small Cell Lung Cancer

Purpose: Reliable and reproducible methods for identifying PD-L1 expression on tumor cells are necessary to identify responders to anti-PD-1 therapy. We tested the reproducibility of the assessment of PD-L1 expression in non-small cell lung cancer (NSCLC) tissue samples by pathologists.Experimental Design: NSCLC samples were stained with PD-L1 22C3 pharmDx kit using the Dako Autostainer Link 48 Platform. Two sample sets of 60 samples each were designed to assess inter- and intraobserver reproducibility considering two cut points for positivity: 1% or 50% of PD-L1 stained tumor cells. A randomization process was used to obtain equal distribution of PD-L1 positive and negative samples within each sample set. Ten pathologists were randomly assigned to two subgroups. Subgroup 1 analyzed all samples on two consecutive days. Subgroup 2 performed the same assessments, except they received a 1-hour training session prior to the second assessment.Results: For intraobserver reproducibility, the overall percent agreement (OPA) was 89.7% [95% confidence interval (CI), 85.7-92.6] for the 1% cut point and 91.3% (95% CI, 87.6-94.0) for the 50% cut point. For interobserver reproducibility, OPA was 84.2% (95% CI, 82.8-85.5) for the 1% cut point and 81.9% (95% CI, 80.4-83.3) for the 50% cut point, and Cohen's κ coefficients were 0.68 (95% CI, 0.65-0.71) and 0.58 (95% CI, 0.55-0.62), respectively. The training was found to have no or very little impact on intra- or interobserver reproducibility.Conclusions: Pathologists reported good reproducibility at both 1% and 50% cut points. More adapted training could potentially increase reliability, in particular for samples with PD-L1 proportion, scores around 50%. Clin Cancer Res; 23(16); 4569-77. ©2017 AACR.

Prognostic significance of PD-L1 expression on tumor cells and tumor-infiltrating mononuclear cells in upper tract urothelial carcinoma

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

PD-L1 expression as poor prognostic factor in patients with non-squamous non-small cell lung cancer

Objectives

The role of programmed cell death ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC), especially according to histologic type, remains controversial. The purpose of this study was to assess PD-L1 expression and its association with overall survival (OS) and clinicopathologic characteristics in NSCLC.

Materials and methods

Formalin-fixed paraffin-embedded specimens were obtained from 108 patients with surgically resected primary NSCLC. PD-L1 expression was assessed via immunohistochemistry using a histochemistry score system. The relationship between OS or clinicopathologic characteristics and PD-L1 expression was evaluated via the Kaplan-Meier method and Cox proportional hazards model, respectively.

Results

Of 108 NSCLC specimens, 44 had high PD-L1 expression, which was highly associated with histologic type (p = 0.003). Patients without PD-L1 expression had remarkably longer OS than those with PD-L1 expression (median OS: 96 months vs. 33 months, p < 0.001). In the subgroup analysis of non-squamous cell carcinoma, OS was more favorable in those without PD-L1 expression than in those with PD-L1 expression (median OS: 113 months vs. 37 months, p < 0.001). Multivariate analysis revealed that PD-L1 expression (95% confidence interval 1.459-4.520, p < 0.001), male sex and higher tumor-node-metastasis stage were significantly correlated with shorter OS.

Conclusions

This study demonstrated that PD-L1 expression is an independent prognostic factor for poor survival in NSCLC patients, especially those with non-squamous NSCLC.

PD-L1 expression in lung adenosquamous carcinomas compared with the more common variants of non-small cell lung cancer

Lung adenosquamous cell carcinomas (ASCs) is a rare variant of NSCLC with a poorer prognosis and fewer treatment option than the more common variants. PD-L1 expression is reported to be the predictor of clinical response in trials of NSCLC. In our study, PD-L1 expression was evaluated via immunohistochemistry using a specific monoclonal antibody (SP263), and PD-L1 mRNA expression was evaluated via in situ hybridization. This study included 51 ASCs, 133 lung adenocarcinomas, and 83 lung squamous cell carcinomas (SCC). Similar results were obtained for PD-L1 expression measured at the mRNA and protein level (k coefficient, 0.851, P = 1.000). PD-L1 expression was significantly higher in the squamous versus glandular component of the 36 ASCs in which the components were analyzed separately. The PD-L1 expression rate was similar in the squamous cell component of ASCs and lung SCC (38.89% vs. 28.92%, P = 0.293), so does the adenocarcinoma component of ASCs and lung adenocarcinomas (11.11% vs 13.53%, P = 1.000). PD-L1 expression correlated significantly with lymphovascular invasion (P = 0.016), but not with EGFR, KRAS, and ALK mutations in lung ASCs. Anit-PD-L1 is a promising treatment option in lung ASC cases in which PD-L1 upregulated and EGFR mutations are present.

Tumour infiltrating lymphocytes correlate with improved survival in patients with esophageal squamous cell carcinoma

We undertook a study of tumour infiltrating lymphocytes (TILs) in a large and relatively homogeneous group of patients with completely resected esophageal squamous cell carcinoma (ESCC). Hematoxylin and eosin–stained sections of 235 ESCC tumours were evaluated for density of TILs in intratumoural (iTIL) and stromal compartments (sTIL). Foxp3+, CD4+, and CD8+ T cells in tumoural and stromal areas were evaluated by immunohistochemistry. Of the 235 tumours, high sTIL (>10%), and iTIL (>10%) were observed in 101 (43.0%) and 98 (41.7%), respectively. The median follow-up period was 36.0 months (95% CI 29.929–42.071). Univariate analysis revealed that sTIL (>10%), iTIL (>20%), vessels involvement, lymph node metastasis, and clinical stage were significantly associated with postoperative outcome. In multivariate analysis, high sTIL (HR: 0.664, P = 0.019 for Disease free survival; HR: 0.608, P = 0.005 for Overall survival) was identified as independent better prognostic factor. Further analysis, sTIL was identified as independently prognostic factor in Stage III-IVa disease, which was not found in Stage I-II disease. Our study demonstrated that sTIL was associated with better ESCC patients’ survival, especially in Stage III-IVa disease. Assessment of sTIL could be useful to discriminate biological behavior for ESCC patients.

Effect of anti-PD-1 antibody, nivolumab on early gastric cancer

Immunomodulation treatment using anti-programmed cell death protein 1 antibody is a very promising treatment for various types of advanced cancers, including melanoma, non-small cell lung cancer, and renal cell carcinoma. However, the therapeutic effects on early cancers are still unknown. We experienced 2 cases of early gastric cancers coexisting advanced melanomas. In both cases, early gastric cancers did not respond to nivolumab. Both early gastric cancers did not express programed death ligand 1. It was speculated that immunotolerance was not fully established responsible for nivolumab in early gastric cancer, and for this reason, nivolumab could not shrink these tumors. We experienced 2 cases of early gastric cancer, where PD-L1 was negative, not responding to nivolumab.

PD-1, PD-L1 Protein Expression in Non-Small Cell Lung Cancer and Their Relationship with Tumor-Infiltrating Lymphocytes

Background

Immunotherapy targeting the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) checkpoint has shown the good outcomes in non-small cell lung cancer (NSCLC). We investigated PD-1 and PD-L1 protein expression and their correlation with tumor-infiltrating lymphocytes (TILs), and association with survival in NSCLC.

Material/Methods

The expression of PD-1 (NAT105, Cell Marque) and PD-L1 (28-8, Dako) protein was assessed in 55 NSCLC cell lines by immunohistochemistry (IHC). PD-1 (NAT105, Cell Marque) and PD-L1 (22C3, Dako) protein expression was evaluated by IHC, and TIL percentage was scored, in 139 surgically resected specimens from patients with NSCLC.

Results

PD-1 was not expressed on NSCLC cell lines. PD-L1 was expressed on 20 NSCLC cell lines (36.4%). A total of 60 patient samples (43.2%) were positive for PD-1 on the TILs, and 25 (18.0%) were positive for PD-L1 on tumor cells. High expression of PD-1 on tumor cells was significantly correlated with higher expression of PD-L1 (P=0.026) and a higher percentage of TILs (P<0.001). In the Cox regression model, the odds ratio for PD-1 was 2.828 (95% CI: 1.325–11.165; P=0.013) and 8.579 (95% CI: 4.148–22.676; P<0.001) when PD-L1 and TILs were positive. Patients whose tumor cells were PD-L1 negative had a tendency for longer relapse-free survival (RFS) than patients who were PD-L1 positive (1.85 years, 95% CI: 0.77–2.93 vs. 0.97 years, 95% CI: 0.71–1.23; P=0.054).

Conclusions

PD-1 was expressed on TILs in tumor tissues in NSCLC patients. PD-L1 was expressed on both TILs and tumor tissues. PD-1 expression was correlated with PD-L1 on tumor cells and TILs. Patients who were PD-L1 positive tended to experience progression after surgery.

A Comprehensive Analysis of Programmed Cell Death Ligand-1 Expression With the Clone SP142 Antibody in Non-Small-Cell Lung Cancer Patients

BACKGROUND

Programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) have been identified as novel targets for immunotherapy, with anti-PD-1 therapy currently the standard treatment for non-small-cell lung cancer (NSCLC) patients after the failure of first-line chemotherapy treatment. The recent phase II POPLAR and phase III OAK studies showed that atezolizumab, a representative PD-L1 inhibitor, exhibited a survival benefit compared with standard therapy in patients with NSCLC.

PATIENTS AND METHODS

We examined PD-L1 expression in NSCLC using the clone SP142 of POPLAR and OAK studies. PD-L1 expression in 499 surgically resected NSCLC patients was evaluated using immunohistochemistry using SP142. We set cutoff values as 1%, 5%, 10%, and 50%.

RESULTS

The samples from 189 (37.9%), 119 (23.8%), 71 (14.2%), and 39 (7.8%) patients were positive for PD-L1 expression at cutoff values of 1%, 5%, 10%, and 50%, respectively. Fisher exact tests showed that PD-L1 positivity was significantly associated with male sex, smoking, advanced stage, the presence of vascular invasion, squamous cell carcinoma, and wild type epidermal growth factor receptor gene mutation status at all cutoff values. Univariate and multivariate survival analyses revealed that PD-L1-positive patients had a worse prognosis than PD-L1-negative patients only at the 1% cutoff value. Forest plot analyses showed that the 1% cutoff provided a more sensitive value for the prediction of postoperative prognosis.

CONCLUSION

PD-L1 expression varied greatly according to different cutoff values. This study might be a useful reference to understand the results of POPLAR and OAK studies and to select patients likely to benefit from atezolizumab.

Association between PD-L1 expression and driven gene status in NSCLC: A meta-analysis

PURPOSE

We explored the potential clinical association between programmed death-ligand 1 (PD-L1) expression and driven gene status in non-small cell lung cancer (NSCLC).

METHODS

We systemically searched through October 2015. Odd ratios (ORs) with 95% CIs were calculated to examine the association of PD-L1 expression with driven gene status. A random- or fixed-effects model was used.

RESULTS

Nine studies were identified. KRAS-mutant tumors were more likely to be PD-L1 positive than KRAS-wild type tumors (51% vs 36%; OR 1.69; 95% CI 1.01-2.84; p = 0.045). In contrast, PD-L1 expression did not differ by EGFR (OR 0.86; 95% CI 0.43-1.73; p = 0.675) or ALK (OR 1.02; 95% CI 0.44-2.37; p = 0.954) status. In subgroup analysis, there was also no significant association between PD-L1 expression and EGFR status in term of the cut-offs or ethnicity.

CONCLUSION

In conclusion, NSCLC with KRAS mutations showed a trend for higher frequency of positive PD-L1 expression.

PD-L1 over-expression is associated with a poor prognosis in Asian non-small cell lung cancer patients

BACKGROUND

The prognostic role of programmed cell death-ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC) remains controversial. This meta-analysis was conducted to clarify the association of PD-L1 with survival in NSCLC patients.

METHODS

Relevant studies were collected from PubMed, Embase and Web of Science. Only studies in which PD-L1 expression was detected by immunohistochemical staining in NSCLC patients correlated with patient survival data were included. Stata 12.0 was performed in this meta-analysis.

RESULTS

Fifteen studies with 3116 patients were included in this meta-analysis. The combined hazard ratio (HR) of 1.18 (95%CI, 0.90-1.56; P>0.05) shows that PD-L1 over-expression in NSCLC patients didn't associate with overall survival (OS). However, subgroup analysis indicated that PD-L1 over-expression was correlated with poor OS in Asian patients (HR=1.84, 95%CI: 1.14-2.28; P<0.001). Moreover, the results suggested that a significant relationship between PD-L1 expression and OS was also showed in studies with late stage (HR=1.27, 95%CI: 1.06-1.48; P=0.031), poor tumor differentiation (HR=1.86, 95%CI: 1.35-2.64; P=0.001) and anaplastic lymphoma kinase (ALK) translocation (HR=2.58, 95%CI: 1.03-5.78; P=0.028).

CONCLUSIONS

PD-L1 over-expression is correlated with a poor prognosis in Asian NSCLC patients.

Role of PD-1 in Immunity and Diseases

Immunity developed to defend our bodies from foreign particles, including bacteria and viruses. Although effector cells responsible for acquired immunity, mainly T cells, and B cells, are able to distinguish self from non-self, they sometimes attack the body's tissues because of imperfect central tolerance. Several immune check points developed to limit overactivation of these cells. One of the most important immune checkpoints is programmed cell death-1 (PD-1), which is expressed mainly on activated lymphocytes. As its ligands (PD-Ls) are expressed widely in the body and affect the responses against self and foreign antigens, controlling PD-1/PD-L interactions enables the management of several immune-related diseases such as autoimmune disease, virus infection, and cancers. Currently, the strategy of PD-1/ PD-L1 blockade has already been applied to clinical cancer therapy, providing evidences that PD-1 signal is one of the main factors of cancer immune escape in humans. The dramatic efficacy of PD-1 blockade in cancer immunotherapy, promises the control of other immune diseases by PD-1 signal modulation. In this review, we summarize the history of PD-1, subsequent basic studies, and their application to the clinic.

[Expression and Clinical Significance of PD-1 and PD-L1 in Pulmonary Carcinoids]

背景与目的

肺类癌(pulmonary carcinoid, PC)是一种发病率极低的肺部原发性恶性肿瘤，临床预后与其病理特征密切相关。本研究旨在检测分析PC组织中PD-1 (programmed death-1)和PD-L1(programmed death ligand-1)的表达情况及其与类癌患者临床病理生理特征的相关性。

方法

应用免疫组织化学法检测了20例PC石蜡包埋组织标本中PD-1和PD-L1的蛋白表达情况；应用Hscore(HS)评分系统(0-300)对肿瘤组织中PD-L1和PD-1的表达进行了分析评价。

结果

PD-1和PD-L1在PC组织中的阳性表达率分别为40%(8/20)和45%(9/20)。其中，在吸烟PC患者中，PD-1的阳性表达率为63.64%，明显高于不吸烟的患者(11.11%, P < 0.05)；PD-1与PD-L1的阳性表达与类癌患者的年龄、性别、病理类型、临床分期以及有无转移均无明显的相关性(P > 0.05)。

结论

PD-1和PD-L1的表达在40%左右的PC患者中呈阳性。其中，吸烟类癌患者肿瘤组织中PD-1的阳性表达率明显高于不吸烟患者。这些结果提示PD-1和PD-L1的阳性表达可能与PC的发生、发展存在一定的相关性。

Image Analysis-based Assessment of PD-L1 and Tumor-Associated Immune Cells Density Supports Distinct Intratumoral Microenvironment Groups in Non-small Cell Lung Carcinoma Patients

PURPOSE

We investigated the correlation between immunohistochemical PD-L1 expression and tumor-associated immune cells (TAICs) density in non-small cell lung carcinoma (NSCLC) and correlated them with clinicopathologic variables.

EXPERIMENTAL DESIGN

Tumor tissue specimens from 254 stage I-III NSCLCs [146 adenocarcinomas; 108 squamous cell carcinomas (SCCs)] were examined. PD-L1 expression in malignant cells and macrophages and the density of TAICs expressing CD3, CD4, CD8, CD57, granzyme B, CD45RO, PD-1, FOXP3, and CD68 were evaluated using immunohistochemistry and image analysis.

RESULTS

Malignant cells PD-L1 H-score > 5 was detected in 23% of adenocarcinomas and 31% of SCCs, and no significant differences were detected comparing both histologies; the median H-score in macrophages was significantly higher in SCC than in adenocarcinoma (P < 0.001). In adenocarcinoma, high malignant cells PD-L1 expression and high TAIC density correlated with solid histology, smoking history, and airflow limitation. Multivariate analysis demonstrated that high CD57-positive cell density correlated with better recurrence-free survival (RFS; P = 0.0236; HR, 0.457) and overall survival (OS; P = 0.0261; HR, 0.481) rates for SCC. High CD68-positive cell density in intratumoral compartment correlated with better RFS (P = 0.0436; HR, 0.553) for adenocarcinoma. The combination of low CD4/CD8/C68-positive cell density and PD-L1 H-score >5 in malignant cells identified small subset of adenocarcinomas with worse outcomes (RFS: P = 0.036; HR, 4.299; OS: P = 0.00034; HR, 5.632).

CONCLUSIONS

We detected different PD-L1 expression and TAIC density patterns in NSCLC. Distinct groups of tumor microenvironment correlated with NSCLC clinicopathologic features, including outcome. Clin Cancer Res; 22(24); 6278-89. ©2016 AACR.

The expression of PD-L1 protein as a prognostic factor in lung squamous cell carcinoma

BACKGROUND

Programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway-targeted immunotherapy has become the standard option of care in the management of lung cancer. The expression of the PD-L1 protein in lung cancer is expected to be a prognostic factor or to predict the response to PD-1-blocking antibodies. However, the association between PD-L1 positivity and the clinicopathological features and patient outcomes in lung squamous cell carcinoma (SCC) remains unclear because the definitive cut-off value for the expression of PD-L1 protein remains to be established.

MATERIALS AND METHODS

The expression of PD-L1 protein in 205 surgically resected primary lung SCC patients was evaluated by immunohistochemistry with the antibody clone SP142. We generated a histogram to show the proportion of PD-L1-positive carcinoma cells, and set the cut-off values as 1%, 5%, 10% and 50%. Moreover, we examined the proliferative capacity of these tumors using Ki-67 immunohistochemistry.

RESULTS

The samples from 106 (51.7%), 72 (35.1%), 61 (29.7%) and 37 (18.0%) patients were positive for the expression of PD-L1 protein at cut-off values of 1%, 5%, 10% and 50%, respectively. Fisher's exact test showed that, for almost all of the factors, PD-L1 positivity was not associated with the clinicopathological features with any of the four cut-off values. Univariate and multivariate survival analyses revealed that the PD-L1-positive patients only had a poorer prognosis than the PD-L1-negative patients at the 1% cut-off value. The Ki-67 labeling index in the PD-L1-positive patients was higher than that in the PD-L1-negative patients.

CONCLUSIONS

The expression of PD-L1 protein was associated with a poor prognosis in lung SCC patients. The 1% cut-off value for PD-L1 might become a better predictive marker than the other cut-off values.

PD-L1 expression in basaloid squamous cell lung carcinoma: Relationship to PD-1+ and CD8+ tumor-infiltrating T cells and outcome

PD-1/PD-L1 inhibitors demonstrated durable clinical responses in patients with lung squamous cell carcinoma. However, the expression pattern of PD-L1 and the presence of CD8⁺ and PD-1⁺ tumor-infiltrating T cells in the basaloid variant of squamous cell carcinoma remain unknown. immunohistochemistry analysis of PD-L1 expression, with three recently validated monoclonal antibodies used in clinical trials (clones SP142, SP263, and 28-8), and detection of CD8⁺ and PD-1⁺ tumor-infiltrating T cells was performed on whole-tissue sections from 56 patients following surgery for basaloid squamous cell carcinoma. Data were correlated to clinicopathological parameters and outcome. Fair to poor concordance was observed between the SP142 vs SP263 clones, and SP142 vs 28-8 (κ range, 0.018-0.412), while the 28-8 and SP263 demonstrated a strong correlation in both the tumor cell and immune cell compartments (κ=0.883, and κ=0.721). Expression of PD-L1 correlated with a high content of CD8⁺ and PD-1⁺ tumor-infiltrating T cells when using SP142 (P=0.012; P=0.022), but not with SP263 or 28-8 (P=0.314; P=0.611). In the multivariate analysis, we found significantly better disease-free and overall survival rates for high PD-L1 expression with SP142, CD8⁺ and PD-1⁺ tumor-infiltrating T cells (P=0.003; P=0.007). No significant prognosis value was observed for SP263 and 28-8 clones, except a correlation between improved overall survival and SP263 in the univariate analysis (P=0.039), not confirmed in the multivariate model. In conclusion, we report that the expression of PD-L1 and the content of CD8⁺ and PD-1⁺ tumor-infiltrating T cells is an independent indicator of better outcome in basaloid squamous cell carcinoma patients, although the observed effect is dependent on the PD-L1 immunohistochemistry assay.