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

Serum-derived exosomal PD-L1 expression to predict anti-PD-1 response and in patients with non-small cell lung cancer

PD-L1 expression is the most useful predictive biomarker for immunotherapy efficacy on non-small cell lung cancer (NSCLC), and CD8+ tumor-infiltrating lymphocytes (CD8+ TILs) play an essential role in the clinical activity of immunotherapy. PD-L1 is found on the exosome’s surface, and PD-L1 expressing exosomes can inhibit antitumor immune responses. This study aimed to analyze tumor PD-L1 expression, serum exosomal PD-L1, and CD8+ TILs to investigate anti-PD-1 response and clinicopathological outcomes in NSCLC. One hundred twenty patients with stage I–III NSCLC were enrolled, and serum samples collected during the initial surgery were pooled. The Human CD274/PD-L1 ELISA kit was used to quantify the exosomal PD-L1. Exosomal PD-L1 levels were significantly correlated with tumor PD-L1 levels (p < 0.001) and the number of CD8+ TILs (p = 0.001). Patients with exosomal PD-L1 ≥ 166 pg/mL tended to have a worse RFS than those with < 166 pg/mL in all stage (p = 0.163) and stage I patients (p = 0.116). Seventeen patients exhibited postoperative recurrences and received anti-PD-1 treatment. The disease control rate of patients with exosomal PD-L1 ≥ 166 pg/mL was 100%. The measurement of serum exosomal PD-L1 as a quantitative factor with tumor PD-L1 status may help predict anti-PD-1 response and clinical outcomes in patients with NSCLC.

PD-(L)1 Inhibitors as Monotherapy for the First-Line Treatment of Non-Small-Cell Lung Cancer Patients with High PD-L1 Expression: A Network Meta-Analysis

Programmed cell death-ligand 1 (PD-L1) has emerged as a potential biomarker for selection of patients more likely to respond to immunotherapy and as a prognostic factor in non-small cell lung cancer (NSCLC). In this network meta-analysis, we aimed to evaluate the efficacy of first-line anti-PD-(L)1 monotherapy in advanced NSCLC patients with high PD-L1 expression (≥50%) compared to platinum-based chemotherapy. We also evaluated efficacy outcomes according to tumor mutational burden (TMB). To that end, we conducted a systematic review. Six clinical trials with 2111 patients were included. In head-to-head comparisons, immunotherapy showed a significant improvement in progression-free survival (PFS: HRpooled = 0.69, 95% CI: 0.52-0.90, p = 0.007), overall survival (OS: HRpooled = 0.69, 95% CI: 0.61-0.78; p < 0.001) and overall response rate (ORR) (Risk ratio (RR)pooled = 1.354, 95% CI: 1.04-1.762, p = 0.024). In the assessment of relative efficacy for PFS through indirect comparisons, pembrolizumab (results from KEYNOTE-024) ranked highest followed by cemiplimab and atezolizumab, with statistical significance determined for some of the drugs. In terms of OS, cemiplimab ranked highest followed by atezolizumab and pembrolizumab, although non-significant OS was determined for these drugs. In conclusion, PD-(L)1 inhibitor monotherapy improves efficacy outcomes in the first line setting of advanced NSCLC patients with high PD-L1 expression. Evaluations with longer follow up are still needed to determine the superiority of any specific drug.

Clinicopathological significance of the expression of PD-L1 in non-small cell lung cancer

INTRODUCTION

PD1/PD-L1 pathway targeting therapies are nowadays an established treatment option for patients with NSCLC. We assessed whether PD-L1 expression in NSCLC tumor cells was associated with specific clinical features or overall survival using four different clones.

METHODS AND RESULTS

A retrospective study included formalin-fixed paraffin embedded (FFPE) surgical tumors from 482 patients. PD-L1 status was assessed with immunohistochemistry in tumor cells on tissue microarrays using clones 28-8, 22C3, SP263 and SP142. Associations with OS were assessed by Kaplan-Meier and multivariate Cox's regression analysis. Patients' median age: 68 years (39-86); histology: adenocarcinoma (AdCa) 61%, squamous-cell carcinoma (SqCC) 33%, and large cell carcinoma (LCC) 6%; p-stage: IA (46%), IB (30%), IIA (10%), IIB (11,4%), IIIA (1,2%), IIIB - IV (0,4%). PD-L1 positivity (≥1%) in NSCLC for clones 28-8, 22C3, SP263, SP142 was 41.5%, 34.2%, 42.7%, 10.4%, respectively (Pearson Chi-square p < 0.0001). PD-L1 expression was correlated with histology, tumor size and grading. Statistically significant association between PD-L1 expression and OS in NSCLC and Non-AdCa was observed with clone SP142 (log-rank p = 0.045 and p = 0.05, respectively). Statistically significant association between PD-L1 expression and OS in LCC was observed with clones 22C3 (log-rank p = 0.009) and SP263 (log-rank p = 0.050).

CONCLUSIONS

Overexpression of the PD-L1 clone SP142 was associated with poor overall survival in NSCLC and Non-AdCa. Clones 22C3 and SP263 were associated with poor prognosis in LCC. PD-L1 status might serve as a prognostic marker in NSCLC.

Detection of programmed cell death-ligand 1 using 22C3 antibody in patients with unresectable stage III non-small cell lung cancer receiving chemoradiotherapy

BACKGROUND

The expression of programmed cell death-ligand 1 (PD-L1) is a biomarker for administering immune check point inhibitors in patients with advanced stage non-small cell lung cancer. Although the consolidation therapy of durvalumab after definitive chemoradiotherapy has become the new standard of care for patients with unresectable stage III non-small cell lung cancer, the prevalence and prognostic role of PD-L1 expression in this population remain unclear.

METHODS

We retrospectively reviewed data from patients with unresectable stage III non-small cell lung cancer who received definitive chemoradiotherapy at our institution between 2012 and 2017. Levels of PD-L1 were assessed using 22C3 antibody, and associations of progression-free and overall survival rates with PD-L1 statuses at a tumor proportion score cutoff of 1% were analyzed.

RESULTS

Among the 104 patients enrolled, PD-L1 statuses were as follows: tumor proportion score < 1%, 73 (70.2%); 1-49%, 21 (20.2%); and ≥ 50%, 10 (9.6%). The number of patients with stage III non-small cell lung cancer with pretreatment PD-L1 tumor proportion score ≥ 1% was less than the number with advanced stage disease. There was no association between patient characteristics and PD-L1 status, and no significant differences were observed in progression-free and overall survival rates relative to PD-L1 status.

CONCLUSION

Expression of PD-L1 in patients with stage III non-small cell cancer before chemoradiotherapy should be assessed because of the low prevalence of tumors with tumor proportion scores ≥ 1%. Further studies are needed to clarify whether durvalumab improves survival after definitive chemoradiotherapy, irrespective of tumor PD-L1 expression.

Distribution and Expression of Programmed Death Ligand -1 (PD-L1) in Non-Small Cell Carcinomas of the Lung in a Tertiary Care Centre in South India

OBJECTIVE

Non-small cell lung carcinomas often present at an advanced stage with a grim prognosis. Immune checkpoint (ICP) inhibitors have drastically changed the scenario, and the response to ICP inhibitors is determined by analyzing the expression of PD-L1 by immunohistochemistry. PD-L1 immunohistochemistry helps in optimizing the treatment, and avoiding unnecessary exposure of patients to the toxic effects of the drugs that are ineffective and expensive in non-expressing tumors. This study was conducted to assess the prevalence of the expression of PD-L1 in non-small cell carcinomas of the lung diagnosed at our institution, which is a tertiary care center in South India.

MATERIAL AND METHOD

The PD-L1 immunohistochemistry of 77 cases of non-small cell carcinomas of the lung diagnosed over a period of two years were reviewed and analyzed (2018-2020). All tissues were fixed in 10% neutral buffered formalin and processed by standard methods, and the Ventana SP263 clone was used.

RESULTS

Seventy-seven cases of non-small cell lung carcinomas were reviewed and studied for (PD-L1) expression. 35/77 (45%) of the cases had PD-L1 expression (≥ 1%) and 14 (18 %) had high (PD-L1) expression. Also there was a male preponderance of 2.3:1. High PD-L1 expression was seen mostly in patients above 60 years of age and was usually associated with high tumor grade.

CONCLUSION

It is important to assess PD-L1 expression in non-small cell carcinomas of patients especially with higher tumor grade and older age groups that they may benefit from immune checkpoint inhibitor therapy.

Impact of Programmed Death Ligand 1 Expression in Advanced Non-Small-Cell Lung Cancer Patients, Treated by Chemotherapy (GFPC 06-2015 Study)

Background

Few data have been published on the clinical and histopathological characteristics of advanced non-small–cell lung cancer (NSCLC) patients with high PD-L1 expression versus intermediate or none and the prognostic value of PD-L1 expression for patients treated with chemotherapy is unknown. This study was undertaken to prospectively assess the prognostic value of tumor-cell (TC) and immune-cell (IC) PD-L1 expressions for advanced NSCLC patients.

Methods

It was a prospective, multicenter study on advanced NSCLC patients, with performance status 0/1, scheduled, consecutively, to receive first-line platin-based chemotherapy. PD-L1 expression was determined immunochemically (Dako Autostainer and monoclonal antibody 22C3) and its impact on progression-free survival (PFS) and overall survival (OS) assessed.

Results

Among 198 patients screened in 19 centers, 140 were included median age: 66.5 ± 10 years; 76.4% men; 79.3% Caucasians; 10.7% nonsmokers; 63.6% adenocarcinomas; <1%, 1–50% and ≥50% TC PD-L1–expression rates were 47.1%, 25.7% and 27.2% of patients, respectively; respective null, intermediate and high rates on ICs were 35.7%, 38.6% and 25.7%. Second- and third-line chemotherapies were administered to 58.6% and 26.4% of the patients, respectively. None received immunotherapy. First-, second- and third-line median (95% CI) PFS lasted 4.6 (3.6–5.2), 3.7 (2.3–4.7) and 2.2 (1.5–4.3) months, respectively; median OS was 16.9 (11.4–19.9) months. No significant PFS and OS differences were observed according to TC or IC PD-L1 expression.

Conclusion

According to the results of this prospective, multicenter study, neither TC nor IC PD-L1 expression appears to be prognostic for chemotherapy-managed advanced NSCLC patients.

Advances in the Treatment of Stage III Non-Small Cell Lung Cancer

Treatment of stage III non-small cell lung cancer (NSCLC) traditionally has involved combinations of chemotherapy, radiation, and surgical resection. Although the multimodality approach remains standard, only a fraction of patients with stage III lung cancer can undergo complete resection, and long-term prognosis remains poor. The PACIFIC trial generated significant enthusiasm when it demonstrated that the programmed death ligand-1 inhibitor, durvalumab, improved survival in patients with unresectable stage III NSCLC after completion of definitive concurrent chemoradiation. This article reviews the indications for traditional therapies in stage III NSCLC and highlights ongoing advances that have led to the incorporation of novel therapeutic agents.

Prognostic significance of PD-L1 in advanced non-small cell lung carcinoma

This study aimed to investigate the prognostic value of PD-L1 in Chinese patients with non-small cell lung carcinoma (NSCLC).In this retrospective study, 97 patients with NSCLC were consecutively recruited. The expression profiling of PD-1, PD-L1, p53 and Ki-67 was detected by immunohistochemistry. Median survival time was estimated by Kaplan-Meier survival curve with log-rank test. Risk factors were evaluated by Cox Proportional Hazards regression models.The median tumor size was larger (3.5 cm) among patients with positive PD-L1 expression, compared to those with negative expression (2.0 cm; P < .01). Compared to those with negative PD-L1 expression, patients with positive PD-L1 expression had significantly higher rates of nerve invasion (26.3% vs 5.0%; P < .01), blood vessel invasion (47.4% vs 20.0%; P < .01) and lymph node metastasis (64.9% vs 27.5%; P < .01), more advanced tumor stage (P < .01) and Ki-67 index (P < .01). PD-L1 expression status was not significantly associated with disease-free (DFS) or overall survival (OS). However, for patients with advanced disease, PD-L1 positive expression was related to worse outcome (HR: 4.13; 95% CI: 1.06-16.12).Positive PD-L1 expression is associated with more aggressive pathological features and poorer prognosis in advanced stage NSCLC.

Comparative expression analysis of PD-1, PD-L1, and CD8A in lung adenocarcinoma

BACKGROUND

As a new strategy for advanced lung adenocarcinoma (LUAD), programmed cell death protein 1 (PD-1) pathway inhibitors have been used in clinic for several years. However, the roles of PD-1, programmed cell death-ligand 1 (PD-L1), and CD8A in LUAD are still unclear. In the study, we aimed to assess the correlation between the mRNA expression of these three factors and the clinical characteristics of LUAD, and to explore the influence of the PD-1/PD-L1/CD8A axis on the prognosis of LUAD.

METHODS

The mRNA expression data and clinical characteristics of LUAD patients were retrieved from The Cancer Genome Atlas (TCGA). The optimal cutoff value for PD-1, PD-L1, and CD8A was determined by Cutoff Finder. The chi-square test was used to compare categorical variables. The prognostic effects of variables were analyzed using the Kaplan---Meier method and the Cox proportional hazards model.

RESULTS

A total of 484 cases were enrolled in this study according to the selection process. The optimal cutoff values for identifying high/low mRNA expression were defined as 27.4 for PD-1, 29.41 for PD-L1, and 95.52 for CD8A. The high expression of PD-1 (P=0.015) and PD-L1 (P=0.027) was more frequent in women than in men. The high expression of PD-1 (P=0.003), PD-L1 (P=0.002), and CD8A (P=0.003) was associated with early T status, whereas CD8A showed a significantly higher expression in both the early stage (P=0.006) and early N stage groups (P=0.031). PD-1, PD-L1, and CD8A were significantly positively correlated among pairs (P<0.001). High expression of each of the three genes was associated with better prognosis (P=0.030 for PD-1, P=0.046 for PD-L1, P=0.019 for CD8A), although the relation did not reach statistical significance in the Cox regression hazards model.

CONCLUSIONS

The study defined a group of cutoff values for PD-1, PD-L1, and CD8A to identify high and low mRNA expression in LUAD. The high expression of PD-1, PD-L1, and CD8A was associated with early T status, and CD8A showed significantly higher expression in both early stage and early N stage groups. Although the high expression of each of these three genes was associated with favorable overall survival (OS), they were not independent prognostic factors.

Gray E. Tumour PD-L1 Expression in Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Antibodies against programmed death-1 (PD-1), and its ligand, (PD-L1) have been approved recently for the treatment of small-cell lung cancer (SCLC). Although there are previous reports that addressed PD-L1 detection on tumour cells in SCLC, there is no comprehensive meta-analysis on the prevalence of PD-L1 expression in SCLC. We performed a systematic search of the PubMed, Cochrane Library and EMBASE databases to assess reports on the prevalence of PD-L1 expression and the association between PD-L1 expression and overall survival (OS). This meta-analysis included 27 studies enrolling a total of 2792 patients. The pooled estimate of PD-L1 expression was 26.0% (95% CI 17.0–37.0), (22.0% after removing outlying studies). The effect size was significantly heterogeneous (I² = 97.4, 95% CI: 95.5–98.5, p < 0.0001).Positive PD-L1 expression was a favourable prognostic factor for SCLC but not statistically significant (HR = 0.86 (95% CI (0.49–1.50), p = 0.5880; I² = 88.7%, p < 0.0001). Begg’s funnel plots and Egger’s tests indicated no publication bias across included studies (p > 0.05). Overall, there is heterogeneity in the prevalence of PD-L1 expression in SCLC tumour cells across studies. This is significantly moderated by factors such as immunohistochemistry (IHC) evaluation cut-off values, and assessment of PD-L1 staining patterns as membranous and/or cytoplasmic. There is the need for large size, prospective and multicentre studies with well-defined protocols and endpoints to advance the clinical value of PD-L1 expression in SCLC.

Prognostic value of PD-L1 expression in patients with unresectable stage III non-small cell lung cancer treated with chemoradiotherapy

Background

Expression of PD-L1 is the most investigated predictor of benefit from immune checkpoint blockade in advanced NSCLC but little is known about the association of PD-L1 expression and clinicopathological parameters of patients with unresectable stage III NSCLC.

Methods

National registry data was searched for medical records of consecutive inoperable stage III NSCLC patients treated with ChT and RT from January 2012 to December 2017. Totally 249 patients were identified that met inclusion criteria and of those 117 patients had sufficient tissue for PD-L1 immunohistochemical staining.

Results

Eighty patients (68.4%) expressed PD-L1 of ≥ 1% and 29.9% of more than 50%. Median PFS was 15.9 months in PD-L1 negative patients and 16.1 months in patients with PD-L1 expression ≥ 1% (p = 0.696). Median OS in PD-L1 negative patients was 29.9 months compared to 28.5 months in patients with PD-L1 expression ≥ % (p = 0.888). There was no difference in median OS in patients with high PD-L1 expression (≥ 50%) with 29.8 months compared to 29.9 months in those with low (1–49%) or no PD-L1 expression (p = 0.694). We found that patients who received a total dose of 60 Gy or more had significantly better median OS (32 months vs. 17.5 months, p < 0.001) as well as patients with PS 0 (33.2 vs. 20.3 months, p = 0.005).

Conclusions

In our patients PD-L1 expression had no prognostic value regarding PFS and OS. Patients with good performance status and those who received a total radiation dose of more than 60 Gy had significantly better mOS.

Novel PD-L1 mAb HC16 reveals upregulation of PD-L1 in BAC subtype

Programmed death-ligand 1 (PD-L1) is an inhibitory transmembrane protein that can prevent autoimmune response. Upregulated PD-L1 serves as a predictive biomarker for patients who may respond well to immune checkpoint therapies. However, variable associations of PD-L1 level with prognoses have been reported. In this study, a short peptide sequence corresponding to PD-L1 amino acids 172-187 (from the extracellular Ig-like C-type domain, and with high predicted antigenicity and hydrophilicity) was used to generate a monoclonal antibody (mAb). The resultant PD-L1 mAb, clone HC16, was examined for binding specificity and reactivity in cancer cell-lines, as assessed by immunocytochemical, immunoblotting, and co-immunoprecipitation. The potential diagnostic and clinical applicability of clone HC16 was further tested using malignant tissue arrays derived from various cancer types analyzed with an automated immunohistochemical (IHC) staining platform. Additionally, tumor samples from patients diagnosed with non-small cell lung cancer (NSCLC) were analyzed by western blotting. Clone HC16 showed obvious staining activity in lung and breast cancer tissues. Interestingly, we observed that PD-L1 level was negatively associated with clinical stage in NSCLC. Strong PD-L1 expression tended to be found in patients diagnosed with bronchioloalveolar carcinoma (BAC). These results demonstrate that clone HC16 harbors good target specificity and is suitable for further development in diagnostic tools to assess PD-L1 expression in human tissues. In addition, our findings also suggest a role for PD-L1 in a non-invasive subtype of lung cancer.

Biphasic prognostic significance of PD-L1 expression status in patients with early- and locally advanced-stage non-small cell lung cancer

Programmed cell death-ligand 1 (PD-L1) expression on tumor cells is induced by interferon-gamma, suggesting the induction of an anti-tumor immune response. In turn, binding of PD-L1 to programmed cell death 1 (PD-1) triggers an immune checkpoint pathway that contributes to tumor growth. Though it remains to be elucidated, the clinical significance of PD-L1 expression might vary with tumor progression in non-small-cell lung cancer (NSCLC). Immunohistochemical analysis of PD-L1 was done in tumor specimens from patients who underwent radical surgery for stage I-IIIA NSCLC (n = 228). Tumor PD-L1 expression intensity was semi-quantitatively scored and its correlation with various clinicopathological features and postoperative relapse-free survival (RFS) was assessed relative to pathological stage. In stage I, postoperative RFS was significantly prolonged in patients with a high PD-L1 score compared with a low PD-L1 score, exhibiting 5-year relapse-free probabilities of 94.1% and 75.1%, respectively (P = 0.031). A multivariate analysis revealed that a high PD-L1 score was a prognostic factor of longer postoperative RFS (hazard ratio: 0.111, P = 0.033). Conversely, in stages II and IIIA, patients with a high PD-L1 score tended to suffer from postoperative tumor recurrence. In early-stage NSCLC, high tumor PD-L1 expression status represents a biomarker to predict good prognosis after radical surgery and may reflect the induction of an antitumor immune response. However, in locally advanced stage NSCLC, tumor PD-L1 expression status may reflect the execution of an immune checkpoint pathway and predicts the incidence of postoperative tumor recurrence.

Programmed cell death-ligand 1 expression in stromal immune cells is a marker of breast cancer outcome

Purpose: The programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) axis plays an important role in antitumor immune responses. However, there is considerable inconsistency regarding the prognostic value of PD-L1 expression status in breast cancer. We sought to evaluate the differential prognostic impacts of tumoral versus stromal immune cell PD-L1 expression in primary breast cancer.

Materials & Methods: Both tumoral and stromal immune PD-L1 expression in formalin-fixed, paraffin-embedded tumor samples from 233 breast cancer patients without initial stage IV metastases were evaluated by immunohistochemistry using a mouse monoclonal anti-PDL1 antibody. Clinicopathological variables were also documented. A Cox regression model was used to assess the association of tumoral/stromal immune PD-L1 expression with clinical outcome using disease-free survival (DFS) as the primary end point.

Results: Both tumoral and stromal immune PD-L1 expression were associated with aggressive tumor characteristics, including higher histologic grade, as well as negative estrogen receptor, negative progesterone receptor, and positive human epithelial growth factor receptor 2 (HER2) status Multivariate analyses further demonstrated that stromal immune cell, but not tumoral, PD-L1 expression was a favorable prognostic factor for survival.

Conclusions: Despite its association with aggressive tumor features, PD-L1 expression on stromal immune cells emerged as a positive prognostic biomarker in breast cancer. This pro-survival effect might reflect the presence of a strong antitumor immune response that leads to PD-L1 expression.

PD-L1 expression with respect to driver mutations in non-small cell lung cancer in an Asian population: a large study of 1370 cases in China

Background

Programmed cell death ligand 1 (PD-L1) expression with respect to genetic alternations has not been well established in non-small cell lung cancer (NSCLC), especially in the Asian population.

Methods

We reviewed 1370 NSCLC patients from a prospectively maintained database. Immunohistochemistry was performed on tumor cells and tumor-infiltrating lymphocytes (TILs) using the VENTANA (SP142) anti-PD-L1 antibody. The tumor proportion score (TPS) cutoff values were set at ⩾1% and ⩾50%, and the immune proportion score (IPS) cutoff values were set at ⩾1% and ⩾10%.

Results

In tumor cells, PD-L1 positivity was observed in 405 (29.6%), 122 (8.9%), and 27 (2.0%) patients with TPS cutoff values at ⩾1% and ⩾50%. Contrastingly, TILs of 1154 (84.2%) and 346 (25.3%) patients stained positive at IPS cutoff values of ⩾1% and ⩾50%, respectively. PD-L1 expression was more common in patients who were mutation-negative irrespective of the TPS cutoff values and tumor size. PD-L1 expression in tumor cells was less frequent in patients harboring EGFR mutations (18.8% TPS ⩾ 1% and 4.6% TPS ⩾ 50%). Conversely, PD-L1 expression was high in the presence of KRAS mutations (47.3% TPS ⩾ 1% and 22.5% TPS ⩾ 50%). Overall, KRAS, BRAF, PICK3A, MET mutations and ROS1 and RET translocations were more frequent, while EGFR and HER2 mutations and ALK translocations were less frequent compared with the overall PD-L1 expression levels. Although the difference between TILs among the PD-L1-positive cases was comparatively small, PD-L1 positivity was less prevalent in EGFR-mutated tumors and more common in those with KRAS mutations, ROS1 translocations, BRAF mutations, or MET mutations.

Conclusion

Our study showed the heterogeneity in PD-L1 expression with respect to nine major oncogenic drivers in China. Future studies are warranted to further clarify the association between PD-L1 expression and driver mutations in NSCLC.

Programmed Cell Death Ligand 1 Expression in Resected Non-Small Cell Lung Cancer

BACKGROUND

Recently, anti-programmed cell death 1 (PD-1) and anti-programmed cell death ligand 1 (PD-L1) immunotherapies have yielded promising outcomes for patients with advanced non-small cell lung cancer (NSCLC) and led to great interest in applying these agents to treat resectable early-stage NSCLC. The objective of our study was to evaluate PD-L1 protein expression in resectable early-stage NSCLC specimens from a large Northern European cohort, examine the relationship to clinical characteristics, and demonstrate the prognostic role in resected NSCLC.

MATERIALS AND METHODS

A large cohort of 875 NSCLC tumors consisted of 337 patients from Sweden and 538 patients from Norway was studied. All the patients had undergone pulmonary resection, and most patients had had early-stage NSCLC. PD-L1 protein expression was assessed by immunohistochemistry using the Dako PD-L1 22C3 pharmDx kit. The tumor proportion score for PD-L1 protein expression was compared with comprehensive demographic and clinicopathologic data.

RESULTS

The overall prevalence of PD-L1 protein expression in the resectable NSCLC cohort was 9.5% at a tumor proportion score cutoff of ≥ 50%. Stage I NSCLC had lower PD-L1 expression compared with that of the other stages (P = .0012). PD-L1 expression correlated with wild-type EGFR gene expression (P = .0156) and mutated KRAS gene expression (P = .0004). No significant association was found between PD-L1 expression and mortality after multivariable adjustment for clinical characteristics, although the survival curves showed PD-L1 expression significantly correlated with a poor prognosis in the total NSCLC cohort and in the adenocarcinoma subgroup.

CONCLUSION

PD-L1 expression in the present large cohort of resectable NSCLC was relatively low compared with data from clinical trials of advanced NSCLC. PD-L1 expression correlated positively with tumor stage, wild-type EGFR, and KRAS mutation. PD-L1 expression was not found as an independent prognostic factor in the present study. These findings could be important in the future when evaluating the role of anti-PD-1/PD-L1 immunotherapy in the setting of neoadjuvant or adjuvant trials for early-stage resectable NSCLC.

PD-L1 expression is a promising predictor of survival in patients with advanced lung adenocarcinoma undergoing pemetrexed maintenance therapy

This study aimed to identify potential predictive factors for the survival of advanced lung adenocarcinoma patients undergoing pemetrexed maintenance therapy. 122 advanced lung adenocarcinoma patients who received pemetrexed maintenance therapy were retrospectively analyzed. Kaplan–Meier method with Log-rank test was used for survival analysis. Univariate and multivariate Cox regression were performed to evaluate prognostic factors for overall survival (OS) and progression-free survival (PFS). Bivariate correlation analysis was used for exploratory purpose. For the whole cohort of 122 patients, median PFS was 11.97 months (95% CI 10.611–13.329) and estimated median OS was 45.07 months (95% CI 31.690–58.450). The mPFS of ALK-positive patients was superior to negative patients (18.27 vs. 11.90 months; P  = 0.039). Patients with ECOG PS 0 (14.4 vs. 11.1 months; p = 0.040) and patients with single-organ metastasis (19.0 vs. 11.0 months; p = 0.014) had prolonged median PFS. Compared with the low PD-L1 expression group, PFS of high PD-L1 expression group were improved (13.6 vs. 11.1 months, p = 0.104, at 1% cut-off; 17.5 vs. 11.1 months, p = 0.009, at 10% cut-off; and 27.5 vs. 11.4 months, p = 0.005, at 50% cut-off). No differences were found between EGFR positive and negative patients. PD-L1 expression was an independent prognostic factor for both PFS and OS times (PFS: HR, 0.175; P  = 0.001; OS: HR, 0.107; P  = 0.036). Bivariate correlation showed a significant positive correlation between PD-L1 expression and PFS (correlation coefficient R = 0.485, P  < 0.001). High PD-L1 expression could be a potential effective predictor for favorable survival of advanced lung adenocarcinoma patients undergoing pemetrexed maintenance therapy.

Immune Checkpoint Inhibitors and Cardiac Toxicity in Patients Treated for Non-Small Lung Cancer: A Review

Lung cancer is a major cause of cancer-related mortality worldwide, both in men and women. The vast majority of patients are diagnosed with non-small-cell lung cancer (NSCLC, 80-85% of lung cancer cases). Therapeutics named immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment in the last decade. They are monoclonal antibodies, and those directed against PD-1 (programmed cell death protein 1) or PD-L1 (programmed cell death-ligand 1) have been used in the treatment of lung cancer and significantly improved the prognosis of NSCLC patients. However, during treatment with ICIs, immune-related adverse events (irAEs) can occur in any organ and any tissue. At the same time, although cardiac irAEs are relatively rare compared to irAEs in other organs, they have a high mortality rate. The two most common clinical manifestations of immunotherapy-related cardiotoxicity are myocarditis and pericarditis. Various types of arrhythmias have been reported in patients treated with ICIs, including the occurrence of life-threatening complete atrioventricular block or ventricular tachyarrhythmias. Here, we aim to summarize the incidence, clinical manifestations, underlying mechanisms, diagnosis, and treatment strategies for ICI-associated cardiotoxicity as these issues become very important in view of the increasing use of ICI in the treatment of lung cancer.

Nanobodies as non-invasive imaging tools

Antibodies and antibody fragments have found wide application for therapeutic and diagnostic purposes. Single-domain antibody fragments, also known as 'heavy-chain variable domains' or 'nanobodies', are a recent addition to the toolbox. Discovered some 30 years ago, nanobodies are the smallest antibody-derived fragments that retain antigen-binding properties. Their small size, stability, specificity, affinity and ease of manufacture make them appealing for use as imaging agents in the laboratory and the clinic. With the recent surge in immunotherapeutics and the success of cancer immunotherapy, it is important to be able to image immune responses and cancer biomarkers non-invasively to allocate resources and guide the best possible treatment of patients with cancer. This article reviews recent advances in the application of nanobodies as cancer imaging agents. While much work has been done in preclinical models, first-in-human applications are beginning to show the value of nanobodies as imaging agents.

Clinicopathological correlation of PD-L1 and TET1 expression with tumor-infiltrating lymphocytes in non-small cell lung cancer

The immunohistochemical analysis of PD-L1 expression is still important in cancer immunotherapy. PD-L1 expression is affected by various tumor microenvironmental factors including tumor infiltrating lymphocytes (TILs) and DNA methylation biomarkers. Given the complex communication between tumor cells and immune cells, we analyzed the expression of PD-L1 and TET1 with TILs in human NSCLC and the correlation with various clinicopathological characteristics and patient prognosis. A total of 96 cases of NSCLC were enrolled in this study. Using tissue microarray, we performed immunohistochemical staining to analyze PD-L1 and TET1 expression. Image-Pro Plus was used as an automated imaging analysis software program to analyze the density of CD3+, CD4+ and CD8 + TILs. PD-L1 expression was positively correlated with the density of CD3+, CD4+ and CD8 + TILs (p = 0.038, p = 0.020, and p = 0.009, respectively); however, no significant relationship existed between TET1 expression and any TILs. The survival analysis revealed that a high PD-L1 expression was associated with favorable prognosis for OS (p = 0.049) and DFS (p = 0.029) in advanced-stage II-IV patients, but not in early stage I. Density of CD8+ TILs was an independent and favorable prognostic factor for DFS (p = 0.008) and OS (p = 0.002) in early-stage I patients. However, high TET-1 expression was associated with poor prognosis for OS (p = 0.029) in total NSCLC patients. These findings suggest the correlation and favorable prognostic impact of PD-L1 and TILs in NSCLC. In addition, DNA demethylase TET1 has oncogenic effects, showing association with poor prognosis.

Clinical Impact of the Epithelial-Mesenchymal Transition in Lung Cancer as a Biomarker Assisting in Therapeutic Decisions

Lung cancer is one of the most common solid cancers and represents the leading cause of cancer death worldwide. Over the last decade, research on the epithelial-mesenchymal transition (EMT) in lung cancer has gained increasing attention. Here, we review clinical and histological features of non-small-cell lung cancer associated with EMT. We then aimed to establish potential clinical implications of EMT in current therapeutic options, including surgery, radiation, targeted therapy against oncogenic drivers, and immunotherapy.

PD-L1 as a prognostic biomarker in surgically resectable non-small cell lung cancer: a meta-analysis

Background

PD-L1 tumor expression has been associated with poor prognosis in a variety of solid tumors, including lung cancer, and represents a validated target for immune checkpoint inhibition in advanced malignances. It remains unknown, however, if PD-L1 can be used to predict survival in early stage, surgically treated cancers. This meta-analysis compares PD-L1 tumor expression and long term survival after surgical resection in early non-small cell lung cancer (NSCLC).

Methods

PubMed was searched to identify eligible studies that compared survival of surgically resected stage I–III NSCLC patients according to PD-L1 tumor expression. Included studies were grouped according to measurement criteria of PD-L1 expression: 1%, 5%, 50% cutoffs or H-score. Meta-analysis was performed using a linear mixed-effects model to determine overall survival (OS). I² was used as a measure of heterogeneity.

Results

There were 40 eligible studies, including 10,380 patients. Regardless of cut-off used, higher PD-L1 tumor expression was associated with worse OS [hazard ratio (HR)_1%: 1.59, 95% confidence interval (CI), 1.17–2.17; HR_5%: 1.44, 95% CI, 1.03–2.00; HR_50%: 1.52, 95% CI, 1.02–2.25, HR_H-score: 1.34, 95% CI, 1.04–1.73]. Study heterogeneity was low and not statistically significant under all PD-L1 cutoffs.

Conclusions

PD-L1 expression is consistently associated with worse survival, regardless of how it is quantified. In addition to acting as a prognostic biomarker, PD-L1 may also be used in future as a predictive biomarker for patients most likely to benefit from adjuvant immunotherapy.

Expression of PD-1 and PD-L1 on Tumor-Infiltrating Lymphocytes Predicts Prognosis in Patients with Small-Cell Lung Cancer

Introduction

Immune therapy has shown good results in small-cell lung cancer (SCLC), but the impact of immune microenvironment of the disease is unclear. In this work, we detected expression of programmed death 1 (PD-1), PD-ligand 1 (PD-L1), and other immune biomarkers of cancer. We also analyzed the correlations between these markers and survival in SCLC.

Patients and Methods

Protein expression of PD-1, PD-L1, PD-L2, CD3, CD4, CD8, and FOXP3 was analyzed in surgical tissues from 102 SCLC patients by immunohistochemistry.

Results

Positive expression of PD-1 on tumor-infiltrating lymphocytes (TILs) was found in 40.2% of patients; 37.3% of patients showed positive expression of PD-L1 on TILs; and 3.9% showed positive expression of PD-L1 on tumor cells. PD-L2 protein was not expressed on tumor cells or TILs. Survival analysis showed that positive expression of PD-L1 on TILs was correlated with longer relapse-free survival (RFS) (p=0.004). Positive expression of PD-1 combined with a high ratio of lymphocytes (CD3, p=0.004; CD4, p=0.011; CD8, p=0.009; FOXP3, p=0.009) was associated with significantly better RFS than negative expression of PD-1 combined with a lower ratio of lymphocytes. Positive expression of PD-L1 combined with a high ratio of lymphocytes (CD3, p<0.001; CD4, p=0.001; CD8, p=0.002; FOXP3, p=0.001) was associated with significantly better RFS than negative expression of PD-L1 combined with a lower ratio of lymphocytes. All patients’ stage were between I and III.

Conclusion

PD-1 and PD-L1 expression might be good prognostic factors in SCLC.

Chemoradiotherapy efficacy is predicted by intra-tumour CD8+/FoxP3+ double positive T cell density in locally advanced N2 non-small-cell lung carcinoma

BACKGROUND

Radiotherapy is a standard of care for locally advanced stage III N2 non-small-cell lung carcinoma (NSCLC) combined with surgery/chemotherapy. Radiotherapy is hypothesised to induce tumour immunogenic cell death, to release neoantigen resulting in intra-tumoural immune infiltration and abscopal effect. Conversely, it has not been demonstrated if immune cells are necessary to drive radiotherapy efficacy and predict patient's survival.

PATIENTS AND METHODS

We retrospectively analysed tumour samples and clinical data from 113 patients, 89 resected (PORT) and 24 non-resected (DRC) N2-NSCLC treated with chemotherapy and radiotherapy (same radiotherapy department from 2002 to 2015). The immune environment was characterised with in situ multiplex staining (CD8, FoxP3, PD-L1 and cytokeratin) and correlated with clinical data and survival.

RESULTS

High density of CD8+ T cells was associated with OS (p = 0.04, HR = 1.93 [0.99-3.78]) and DFS (p = 0.003, HR = 2.42 [1.31-4.47]) in the PORT. High density of CD8+/FoxP3+ double positive cells was associated with OS (p = 0.01, HR = 1.97 [1.11-3.48]) in the whole population, with OS (p = 0.05, HR = 1.92 [0.98-3.74]) and PFS (p = 0.03, HR = 1.83 [1.03-3.23]) in the PORT without reaching significance for the DRC. Intermediate PD-L1 expression in tumour cells (TPS = 1-49%) was associated with a higher survival in the PORT.

CONCLUSIONS

Intra-tumoural CD8+ T cell and particularly CD8+/FoxP3+ double positive T cell densities predict survival in stage III N2-NSCLC suggesting the need for a pre-existing intra-tumour immunity to mediate the action of radiotherapy. Density of CD8+/FoxP3+ cells was the best predictor of patient's survival in multivariate analysis and could represent a biomarker of radiotherapy efficacy.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for PD-L1 Testing in Non-small Cell Lung Cancer

BACKGROUND

Programmed death-ligand 1 (PD-L1) expression on cancer cells is a clinically important biomarker to select patients with non-small cell lung cancer (NSCLC) for treatment with programmed death-1/PD-L1 inhibitors. Clinical trials of immunotherapy in patients with NSCLC have required histologic evidence for PD-L1 testing; in clinical practice, cytologic samples commonly are acquired in patients with advanced disease.

RESEARCH QUESTION

This study aims to investigate whether endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples are adequate for PD-L1 testing in NSCLC.

STUDY DESIGN AND METHODS

This study investigates the sampling adequacy of EBUS-TBNA for PD-L1 testing when compared with other methods. Furthermore, the relationship between clinicopathologic characteristics and PD-L1 expression in the study population have been examined. Five hundred seventy-seven NSCLC specimens were analyzed from consecutive patients with NSCLC across six centers in the United Kingdom and one center in the United States between January 2015 and December 2016.

RESULTS

In the EBUS-TBNA group (189 specimens), the overall percentage of patients with successful PD-L1 testing was 94.7%. There was no significant difference in sampling adequacy with other methods of tissue acquisition. Older patients had higher failure rates of PD-L1 testing (OR, 1.06; P = .008). In multivariate analysis, advanced N-stage (P = .048) and presence of brain metastasis (P < .001) were associated with high PD-L1 expression.

INTERPRETATION

This large multicenter study shows that EBUS-TBNA provides samples adequate for PD-L1 testing and that advanced N stage and the presence of brain metastasis are associated with high PD-L1 expression.

The Multiple Faces of Programmed Cell Death Ligand 1 Expression in Malignant and Nonmalignant Cells

Preliminary data suggest that tumor expression of programmed cell death ligand 1 (PD-L1) protein in human cancers, as determined by immunohistochemistry in formalin-fixed, paraffin-embedded tissue samples, may predict clinical response to anti-PD-1/PD-L1 therapy. PD-L1 is not a specific tumor marker and its expression is also observed in various nonmalignant cells, such as macrophages and lymphocytes, causing confusion in immunohistochemistry analysis when these inflammatory cells are overlapping with tumors cells. The aim of the current study was to examine PD-L1 expression in formalin-fixed, paraffin-embedded malignant and nonmalignant cells from human tumors to establish potential characteristic patterns of PD-L1 expression in tumor tissues. We used a commercial PD-L1 clone (E1L3N) previously validated in our laboratory to characterize PD-L1 expression in surgically resected lung adenocarcinomas, lung squamous cell carcinomas, malignant melanomas, renal cell carcinomas, hepatocellular carcinomas, and ductal breast carcinomas. We observed different patterns of PD-L1 expression by malignant cells and nonmalignant cells as membrane, cytoplasmic, and nuclear expression. The distribution of expression was variable including the entire malignant cells population, heterogonous with random distribution, peripheral distribution, minimal expression by few cells and negative expression. Similar, nonmalignant cells showed randomly and peripherally distribution through the tumors. We concluded that the PD-L1 cell protein expression patterns and distributions are variable and differ between resected tumor specimens. The expression and distribution pattern described here provide a useful knowledgment of PD-L1 expression in tumor samples.

Evaluation of radiotherapy combined with targeted therapy and concurrent radiotherapy, chemotherapy in the treatment of Non-Small Cell Lung Cancer with brain metastasis

Objective:

To compare and analyze the clinical efficacy of brain radiotherapy combined with targeted therapy and concurrent radiotherapy and chemotherapy in the treatment of non-small cell lung cancer (NSCLC) with brain metastasis.

Methods:

Fifty-eight patients with NSCLC with brain metastasis who were admitted to our hospital between October 2016 and October 2017 were randomly divided into a control group and an observation group, 29 cases in each group. The control group was treated with concurrent radiotherapy and chemotherapy, while the observation group was treated with whole brain radiotherapy plus targeted therapy. The disease control rate, adverse reactions and survival condition were compared between the two groups.

Results:

The disease control rate of the observation group was 68.97%, significantly higher than 41.38% of the control group (P<0.05); the total incidence of adverse reactions in the observation group was 6.90%, significantly lower than 24.14% of the control group (P<0.05); the median survival time of the observation group was (16.81±5.32) months, significantly longer than that of the control group ((9.76±3.25) months). The one-year and two-year survival rates in the observation group were significantly higher than those in the control group (P<0.05).

Conclusion:

Whole brain radiotherapy combined with targeted therapy is superior to concurrent radiotherapy and chemotherapy in the treatment of NSCLC with brain metastasis and has high safety. It can effectively prolong the life span of patients and is worth clinical promotion and application.

Association between PD-L1 expression and driver gene mutations in non-small cell lung cancer patients: correlation with clinical data

Lung cancer is the leading cause of cancer death worldwide. Recently, promising therapies have emerged based on PD-1/PD-L1 immune checkpoint inhibitors, which have been approved even as frontline treatment for patients with non-small cell lung cancer (NSCLC). We examined the association between PD-L1 expression and clinicopathological parameters as well as overall survival in 220 NSCLC patients. PD-L1 expression was estimated by immunohistochemistry using 22C3 PharmDx Dako assay and was defined as high, if TPS was ≥ 50%, low, if TPS was 1%-49%, and absent, if TPS was < 1%. EGFR mutations were detected by COBAS while KRAS and BRAF mutations by pyrosequencing. ROS1 and ALK rearrangements were estimated by immunohistochemistry with positive cases being confirmed by CISH and FISH, respectively. Data analysis was performed using SPSS v25.0. PD-L1 expression was positively correlated with KRAS mutations. Anti-PD-1 therapy (pembrolizumab) prolonged overall survival compared to any other treatment. This effect was more pronounced in KRAS-mutated cases compared to KRAS wild-type ones. Patients with positive PD-L1 expression - high or low - who had been treated with pembrolizumab, showed significant survival benefit compared to positive or negative PD-L1 expressors who did not receive immunotherapy. In multivariate analysis, PD-L1 status, stage and pembrolizumab treatment were independent variables for overall survival. PD-L1 expression (TPS ≥ 1%) by itself emerged as a poor prognostic factor, while treatment with pembrolizumab prolonged overall survival. KRAS mutations may affect tumour microenvironment and patient's response to immunotherapy. Immune checkpoint inhibitors could represent an alternative therapeutic option particularly for KRAS-mutated NSCLC patients. Further investigation into this notion is warranted in order to validate this observation.

Spatiotemporal Changes in Checkpoint Molecule Expression

Immune checkpoint inhibitors (ICIs), particularly PD-1/PD-L1 blockade, have led to therapeutic breakthrough in patients with advanced malignancy, covering the lung, breast, gastrointestinal, head and neck, urinary system, lymphoma, and solid tumor harboring MSI/dMMR. In certain cancer types, the expression level of immune checkpoint molecule will be required if the immune-based approaches are considered, especially the PD-L1 expression. However, in other types, survival benefit has been proven regardless of PD-L1 expression. It raises a question of how to select patients for immune therapy and whether the expression of immune checkpoint molecules will be optimal biomarkers. Before answering this question, a comprehensive map for the expression of immune checkpoint molecules is needed. In this chapter, we describe our current knowledge on the spatiotemporal changes in the expression of checkpoint molecules. We discuss the different frequencies of expression depending on tumor types and stages, the different patterns between primary and metastatic tumors, as well as the change of expression before and after treatment. The expression of PD-L1 has been most studied, but the threshold that separate "positive" and "negative" PD-L1 expressions and the consistency of testing platform remain under debate. Better understanding on the tumor microenvironment and expression of checkpoint molecules will help to identify patients who will benefit from checkpoint blockade therapy.

[Advances in the Influence of EGFR Mutation on the PD-L1 Expression in Non-small Cell Lung Cancer]

近年来，有关程序性死亡受体1（programmed death-1, PD-1）及其配体（programmed death-1 ligand, PD-L1）抑制剂的研究取得突破性进展，迅速改变着非小细胞肺癌（non-small cell lung cancer, NSCLC）的治疗模式。但表皮生长因子受体（epidermal growth factor receptor, EGFR）突变患者应用PD-1/PD-L1抑制剂的治疗效果并不理想。既往研究显示，肿瘤细胞PD-L1表达率与免疫抑制剂治疗效果存在相关性。但目前EGFR突变对PD-L1表达的影响并不能达成一致。我们将对相关研究进行总结，以期对基础研究或临床治疗有所帮助。

Multicentre study on the consistency of PD-L1 immunohistochemistry as predictive test for immunotherapy in non-small cell lung cancer

AIMS

Investigate the impact of interlaboratory- and interobserver variability of immunohistochemistry on the assessment of programmed death ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC).

METHODS

Two tissue microarrays (TMAs) were constructed from 50 (TMA-A) and 51 (TMA-B) resected NSCLC cases, and distributed among eight centres. Immunostaining for PD-L1 was performed using Agilent's 22C3 pharmDx Assay (pharmDx) and/or a 22C3 laboratory developed test (LDT). The interlaboratory variability of staining- and interobserver variability of scoring for PD-L1 were assessed in selected critical samples (samples at the cut-off of positivity) and non-critical samples. Also, PD-L1 epitope deterioration in time in stored unstained slides was analysed. Krippendorff's alpha values (0=maximal, 1=no variability) were calculated as measure for variability.

RESULTS

For interlaboratory variability of immunostaining, the percentage of PD-L1 positive cases among centres ranged 40%-51% (1% cut-off) and 23%-30% (50% cut-off). Alpha values at 1% cut-off were 0.88 (pharmDx) and 0.87 (LDT) and at 50% cut-off 0.82 (pharmDx) and 0.95 (LDT). Interobserver variability of scoring resulted in PD-L1 positive cases ranging 29%-55% (1% cut-off) and 14%-30% (50% cut-off) among pathologists. Alpha values were at 1% cut-off 0.83 (TMA-A) and 0.66 (TMA-B), and at 50% cut-off 0.77 (TMA-A) and 0.78 (TMA-B). Interlaboratory variability of staining was higher (p<0.001) in critical samples than in non-critical samples at 50% cut-off. Furthermore, PD-L1 epitope deterioration in unstained slides was observed after 12 weeks.

CONCLUSIONS

The results provide insight in factors contributing to variability of immunohistochemical assessment of PD-L1, and contribute to more reliable predictive testing for PD-L1.

Characterization of PD-L1 protein expression and CD8+ tumor-infiltrating lymphocyte density, and their associations with clinical outcome in small-cell lung cancer

Background

This study aimed to characterize programmed death ligand-1 (PD-L1) expression and CD8⁺ tumor-infiltrating lymphocytes (TILs) density, and their impact on survival in patients with surgically resected small-cell lung cancer (SCLC).

Methods

Fifty-six patients with surgically resected SCLC were included. PD-L1 protein expression and CD8⁺ TILs were tested by immunohistochemistry. A meta-analysis of 15 articles with 1,505 patients that investigated the prevalence and prognostic significance of PD-L1 expression in SCLC was conducted.

Results

Twenty-two (39.3%) patients had positive PD-L1 protein expression and 42 (75.0%) had high CD8⁺ TILs density. PD-L1 expression level was not associated with CD8⁺ TILs density (P=0.528). No any association between clinicopathological features and PD-L1 expression level or CD8⁺ TILs density was observed. Positive PD-L1 expression [hazard ratio (HR) =0.374, P=0.002] and high CD8⁺ TILs density (HR =0.429, P=0.008) were independently associated with significantly longer overall survival (OS), which remain the statistical significance in multivariate analyses (P=0.007, P=0.002; respectively). Meta-analysis showed that the prevalence of positive PD-L1 expression was 0.35 [95% confidence interval (CI), 0.22-0.48] and positive PD-L1 expression was correlated with markedly longer OS (HR =0.61; 95% CI, 0.31-0.91) in patients with SCLC.

Conclusions

The prevalence of PD-L1 expression in surgically resected SCLC is lower than that published for NSCLC. There was no association between PD-L1 expression or CD8⁺ TILs density and clinicopathological parameters. PD-L1 expression and CD8⁺ TILs density was independently correlated with better outcome in patients with SCLC.

The Prognostic Value of Programmed Death-Ligand 1 in a Chinese Cohort With Clear Cell Renal Cell Carcinoma

Objective: To investigate the association between tumor PD-L1 expression and patient survival to determine whether PD-L1 represents an independent prognostic feature for patients with non-metastatic clear cell renal cell carcinoma (RCC). Patients and Methods: The tissue bank of the Fudan University Shanghai Cancer Center was queried to identity tissue samples of patients treated with radical nephrectomy, for non-metastatic sporadic clear cell RCC (ccRCC) between 2008 and 2015. Real-time polymerase chain reaction and immunohistochemistry staining was performed to detect the expression level of PD-L1 in paired cancer tissue and paracancerous tissue. Results: Three-hundred-and-thirty patients were enrolled in this study, with a mean age of 55.0 years at surgery and a mean tumor size of 5.2 cm. Two-hundred-and-forty-two (73.3%) and 88 (26.7%) patients showed a high and low expression of PD-L1 mRNA, respectively, while 254 patients had positive PD-L1 immunohistochemistry staining. Two-hundred-and-ninety-two patients had consistent results for mRNA and the PD-L1 protein based on these different detection methods. Patients with high PD-L1 expression were more likely to exhibit adverse pathologic features including an advanced T stage (P = 0.002) and lymph node metastasis (P = 0.044). The Kaplan-Meier curves of PFS and OS stratified by PD-L1 expression had a statistically significant difference. PD-L1 expression maintained a significant predictive role for PFS and OS in the multivariate cox model. Conclusions: Our data suggests that PD-L1 correlates with prognosis in RCC and targeting the PD-1/PD-L1 pathway should be considered in the treatment of RCC patients.

A Molecular Epidemiological Analysis Of Programmed Cell Death Ligand-1 (PD-L1) Protein Expression, Mutations And Survival In Non-Small Cell Lung Cancer

Purpose

To characterize programmed cell death ligand-1 (PD-L1) expression in relation to survival and gene mutation status in patients with advanced NSCLC. The study also explored the influence of tumor mutational burden (TMB) on PD-L1 expression and patient characteristics.

Patients and methods

Adult patients with histologically or cytologically documented Stage IIIB/Stage IV/recurrent/progressive NSCLC, Eastern Cooperative Oncology Group performance status 0 to 3, and >2 lines of prior systemic treatment regimens were included in this retrospective analysis. Patients were treated from 1997 to 2015 at H. Lee Moffitt Cancer Center and Research Institute, Tampa, or at 7 community centers across the United States. PD-L1 expression level was determined using the VENTANA PD-L1 (SP263) Assay. EGFR and KRAS mutation status and ALK rearrangements were determined by targeted DNA sequencing; these were obtained from clinical records where targeted DNA sequencing was not performed. TMB was calculated as the total number of somatic mutations per sample.

Results

From a total of 136 patients included in the study, 23.5% had tumors with high PD-L1 expression (≥25%). There were no significant differences in patient characteristics, overall survival (OS), and progression-free survival (PFS) between patients with high PD-L1 expression (median OS: 39.5 months; median PFS: 15.8 months) vs low PD-L1 expression (<25%; median OS: 38.1 months; median PFS: 18.6 months). PD-L1 expression level correlated (P=0.05) with TMB and was consistent with The Cancer Genome Atlas data.

Conclusion

In this retrospective analysis, survival outcomes of patients with advanced NSCLC were comparable by PD-L1 expression level. EGFR and KRAS mutation status were not found to be significantly associated with PD-L1 expression level, while TMB was weakly associated with PD-L1 expression level. Overall, PD-L1 expression level was not observed to be an independent prognostic biomarker in this cohort of patients with advanced NSCLC treated with chemotherapy.

The PD-L1/PD-1 axis expression on tumor-infiltrating immune cells and tumor cells in pediatric rhabdomyosarcoma

BACKGROUND

Activation of immune checkpoints, e.g. PD-1/PD-L1 axis, in cancer microenvironment, enables evasion of host anti-cancer immune response and drives tumor progression. To date, there have been only a few studies analyzing PD-1/PD-L1 expression in pediatric malignancies.

AIM

In the current study, we aimed to assess PD-L1 and PD-1 expression in pediatric rhabdomyosarcoma (RMS) and to investigate their clinicopathological associations.

MATERIALS AND METHODS

The study enrolled 31 children with RMS. Tissue microarrays with representative tumor tissue samples were stained with anti-PD-1 NAT105 clone (Ventana, Roche) and two different antibodies against PD-L1: SP142 (Ventana, Roche) and 22C3 (DAKO). Adequate positive controls were applied. Their expression was assessed in tumor-associated immune cells (TAICs) and in the tumor cells separately.

RESULTS

We did not detect any positive PD-L1 staining in analyzed tumors using SP142 antibody; however, in 11 cases (35.48%) its expression was revealed by means of 22C3 clone. The staining was restricted to TAICs in all cases, which no reaction in tumor cells. The 5-year relapse free survival (RFS) rate was significantly higher in PD-L1 positive cases (61.5% vs 25.0%, p = 0.024), but it most likely results from more frequent PD-L1 expression in low-stage RMS. PD-1 expression on TAICs was detected in 7 cases and did not influence the prognosis.

CONCLUSIONS

We found that PD-L1 expression on TAICs, as detected with the use of 22C3 clone but not SP142 antibody, tends to be associated with low-stage RMS in children. PD-1 expression on TAICs in RMS is neither associated with distinct clinical course nor with clinicopathological features.

Combination of PD-L1 expression and NLR as prognostic marker in patients with surgically resected non-small cell lung cancer

Background: In recent years, great improvement has been made in immunotherapies for non-small cell lung cancer (NSCLC). Current data have suggested that Programmed cell death ligand 1 (PD-L1) expression might not be an ideal marker for patient selection in isolation. Evidence has been increasing that alternative markers, such as neutrophil-to-lymphocyte ratio (NLR), a biomarker of systemic inflammation response (SIR) previously associated with outcomes in a variety of cancers including NSCLC, might be a predictor for patient selection and the response to therapy. No reports have examined the prognostic value of combination of PD-L1 expression and inflammatory markers such as NLR in NSCLC. This retrospective study explores the relationship between NLR and PD-L1 expression in NSCLC as well as the prognostic value of combination of PD-L1 expression and NLR.

Method: We evaluated tumor PD-L1 expression in 235 surgically resected NSCLC cases by immunohistochemical analysis. Carcinoma cells showing membranous staining for PD-L1 were considered PD-L1-positive cells (Figure 1). Cases with ≥1% tumor membrane staining were considered PD-L1-positive. The association of clinicopathological characteristics with PD-L1 expression was assessed by univariate and multivariate analyses. Moreover, univariate and multivariate analyses were performed to evaluate the predictive impact of PD-L1 expression and other factors on disease-free survival (DFS) and overall survival (OS).

Result: PD-L1 protein expression was elevated in 34.0% of patients at cut-off value of 1%. Univariate analyses showed that PD-L1 expression was significantly higher in men (χ² =5.226, P=0.030), heavy smokers (χ² =18.650, P<0.001), and patients with squamous cell carcinoma (χ² =4.036, P=0.045). No correlations were noted between PD-L1 expression and age, EGFR mutation status or clinical stage. No significant correlations between PD-L1 protein expression and NLR were found. Multivariate logistic regression revealed that smoking index ≥400 was independent predictor of PD-L1 expression (odds ratio [OR], 3.375; P < 0.001). The results of univariate survival analyses showed that clinical stage (log-rank χ² =7.876, P=0.019) was associated with DFS. Smoking index (log-rank χ² =4.832, P=0.028), clinical stage (log-rank χ² =7.582, P=0.023) and adjuvant treatment (log-rank χ² =5.440, P=0.020) were significantly associated with OS. Neither PD-L1 expression nor NLR was found to be associated with DFS or OS. Of interest, when patients were divided in two groups according to combined PD-L1/NLR: patients with PD-L1+/ high NLR as Group 1, other patients as Group 2, Group 1 had significantly shorter DFS as well as OS than Group 2 (DFS: log-rank χ² =5.231, P=0.022, Figure 2A; OS: log-rank χ² =4.742, P=0.029, Figure 2B). In the multivariate analysis, Cox proportional hazards regression models showed that, PD-L1+/ high NLR was associated with a significantly shorter DFS and OS (hazard ratio [HR], 1.394, P=0.040; HR, 1.442, P=0.042, respectively). Stratified analysis showed that the prognostic value of combined PD-L1/NLR can only be observed in cases without epidermal growth factor receptor (EGFR) mutations (DFS: log-rank χ² =5.593, P=0.018, Figure 2C, OS: log-rank χ² =9.323, P=0.002, Figure 2D). In EGFR mutation subgroup, combination of PD-L1 expression and NLR has no relationship with DFS or OS.

Conclusion: We found that combination of PD-L1 expression and NLR may be a promising prognostic indicator, and may also be a good marker for tumor recurrence, especially in the patients with wild-type EGFR.

Programmed Death Ligand 1 Indicates Pre-Existing Adaptive Immune Response by Tumor-Infiltrating CD8+ T Cells in Non-Small Cell Lung Cancer

Aberrant expression of programmed death ligand 1 (PD-L1) on tumor cells impedes antitumor immunity and instigates immune evasion. The remarkable efficacy of immune checkpoint blockade has been confirmed in various solid tumors. However, the correlation between PD-L1 expression and host immunological landscape remains of considerable controversy in non-small cell lung cancer (NSCLC). In the present study, PD-L1 expression and CD8⁺ tumor-infiltrating lymphocyte (TIL) infiltration levels were determined by immunohistochemistry (IHC) in tumor sections of 138 NSCLC patients. The expression level of PD-L1 was positively correlated with the abundance of CD8 ⁺ TILs (p < 0.0001). Furthermore, no constitutive expression of PD-L1 was observed in the majority of six NSCLC cell lines detected by Western blot; but exposure to interferon-γ (IFN-γ), a primary cytokine secreted by activated CD8⁺ T cells, prominently increased PD-L1 expression. Notably, a significantly positive association was determined within PD-L1, CD8 and IFN-γ gene expression by qRT-PCR, which was corroborated by RNA-sequencing from TCGA lung cancer dataset. These findings demonstrate that PD-L1 expression indicates an adaptive immune resistance mechanism adopted by tumor cells in the aversion of immunogenic destruction by CD8⁺ TILs. Both higher expression of PD-L1 and infiltration of CD8⁺ TILs were correlated with superior prognosis (p = 0.044 for PD-L1; p = 0.002 for CD8). Moreover, Cox multivariate regression analysis showed that the combination of PD-L1 and CD8 were independent prognostic factors, which was more accurate in prediction of prognosis in NSCLC than individually. Finally, we found that IFN-γ induced the upregulation of PD-L1 in NSCLC cells, mainly through the JAK/STAT1 signaling pathway. In conclusion, PD-L1 expression is mainly induced by activated CD8⁺ TILs via IFN-γ in the immune milieu and indicates pre-existing adaptive immune response in NSCLC.

The landscape of immune microenvironment in lung adenocarcinoma and squamous cell carcinoma based on PD-L1 expression and tumor-infiltrating lymphocytes

AIMS

The aim of this study was to investigate the tumor microenvironment immune types (TMIT) based on tumor cell programmed cell death ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs) distribution and whether distinct TMIT subtypes (TMIT I, PD-L1^high /TIL^high ; TMIT II, PD-L1^low /TIL^low ; TMIT III, PD-L1^high /TIL^low ; and TMIT IV, PD-L1^low /TIL^high ) differentially affect clinical outcomes of patients with lung adenocarcinoma (LAC) and squamous cell carcinoma (SCC).

METHODS AND RESULTS

Immunohistochemistry (IHC) was applied to evaluate the expression of PD-L1 and the spatial distribution of programmed cell death 1 (PD-1) and CD8 TILs on the surgically resected specimens from 205 cases of LAC and 149 cases of SCC. PD-1 and CD8 TILs were more frequently distributed in SCC than those in LAC, regardless of their infiltrating in the tumor islets or stroma. The density of TILs was a poor prognostic factor in LAC but a favorable one in SCC. PD-L1 levels and its clinical prognostic significance differed in LAC vs SCC. LAC patients with TMIT III and SCC patients with TMIT I had the longest survival, respectively (P = .0197 and .0049). Moreover, TMIT stratification based on tumor cell PD-L1 expression and stromal CD8⁺ TILs could be considered as an independent prognostic factor of SCC patients' survival as determined by both univariate and multivariate analysis.

CONCLUSION

Our study indicates that different type of TMIT provides its specific microenvironment with diverse impact on survival of LAC and SCC patients and highlights the importance of the integrative assessment of PD-L1 status and TILs' spatial distribution to predict patients' prognosis.

Association with PD-L1 Expression and Clinicopathological Features in 1000 Lung Cancers: A Large Single-Institution Study of Surgically Resected Lung Cancers with a High Prevalence of EGFR Mutation

Programmed cell death ligand 1 (PD-L1) expression is an important biomarker for predicting response to immunotherapy in clinical practice. Hence, identification and characterization of factors that predict high expression of PD-L1 in patients is critical. Various studies have reported the association of PD-L1 expression with driver genetic status in non-small cell cancer; however, the results have been conflicting and inconclusive. We analyzed the relationship between PD-L1 expression and clinicopathological factors including driver genetic alterations in 1000 resected lung cancers using a clinically validated PD-L1 immunohistochemical assay. PD-L1 expression was significantly higher in squamous cell carcinoma (SCC) compared to adenocarcinomas. PD-L1 expression in adenocarcinoma was associated with higher N-stage, solid histologic pattern, EGFR wild type, and ALK positive, but no significant association with the clinicopathological factors in SCC. EGFR mutant adenocarcinomas with distinctive clinicopathologic features, especially solid histologic pattern and higher stage showed higher PD-L1 expression. To the best of our knowledge, this study is the largest to evaluate the association between PD-L1 expression and clinicopathological and molecular features in lung cancer with a highly prevalent EGFR mutation. Therefore, our results are useful to guide the selection of lung cancer, even EGFR-mutated adenocarcinoma patients with PD-L1 expression, for further immunotherapy.

Expression and clinical significance of PD-L1 and c-Myc in non-small cell lung cancer

BACKGROUND

It is known that there are insufficient prognostic factors for non-small cell lung cancer (NSCLC). It was reported that PD-L1 was a prognostic factor for NSCLC,and c-Myc regulated the expression of PD-L1. Herein, we investigated c-Myc and PD-L1 expression and their association with overall survival (OS) in NSCLC.

METHODS

Formalin-fixed paraffin-embedded specimens were obtained from 128 patients with surgically resected primary NSCLC. Immunohistochemistry was used to assess the expression of PD-L1 and c-Myc in this study. Pearson's Chi squared test or Fisher's exact test was used to analyze the correlation of the expression of PD-L1 and c-Myc with clinicopathologic features. The relationship between OS and the expression of PD-L1 and c-Myc was evaluated by the Kaplan-Meier method and Cox proportional hazards model, respectively.

RESULTS

Positive expression of PD-L1 was detected in 59 patients (46.1%). Patients with negative expression of PD-L1 had remarkably longer OS than those with positive expression of PD-L1. The positive expression rate of c-Myc in NSCLC accounted for 58.6% (75/128) and its expression was significantly more frequent in males (p = 0.002) and patients with lymph node metastasis (p = 0.029). PD-L1 expression was positively correlated with c-Myc expression (r = 0.459, p < 0.001). The PD-L1 and c-Myc double-positive group had a worse prognosis than other subgroups (p < 0.05), and the PD-L1 and c-Myc double-negative group had a better OS than other subgroups (p < 0.05).

CONCLUSION

Conjoint analysis of the expression of PD-L1 and c-Myc was a better prognostic approach for NSCLC patients.

Clinical significance of PD-L1-positive cancer-associated fibroblasts in pN0M0 non-small cell lung cancer

OBJECTIVES

Cancer-associated fibroblasts (CAFs) are a dominant cell type in tumor stroma and support the generation of pro-tumorigenic microenvironment. CAFs have frequent opportunities to interact with immune cells infiltrating the tumor stroma, but the process remains to be determined. In this study, we focused on immune checkpoint mechanism. We also examined the induction of programmed cell death-ligand 1 (PD-L1) on CAFs by immune cell, and the clinical significance of PD-L1-expressed CAFs in non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

CAFs were isolated from human NSCLC tissues, and PD-L1 expression levels in CAFs were analyzed by real-time polymerase chain reaction and flow-cytometry. Following immunohistochemical analysis of PD-L1 in surgically resected pN0M0 NSCLC (n = 125, including 88 invasive adenocarcinomas and 37 squamous cell carcinomas), the correlation of PD-L1-positive CAFs with clinicopathological features was investigated.

RESULTS

PD-L1 mRNA and protein expression on CAFs was upregulated by exogenously supplemented interferon-gamma (IFN-γ) and downregulated through the depletion of IFN-γ. PD-L1 expression on CAFs was upregulated by co-culture with activated lymphocytes releasing IFN-γ. Immunohistochemistry revealed that PD-L1-positive CAFs were observed in 31 cases (24.8%). Postoperative relapse-free survival was significantly prolonged in patients with PD-L1-positive CAFs as compared with those with PD-L1-negative CAFs, with 5-year relapse-free probabilities of 84.5% and 66.3%, respectively (P = 0.031). Multivariate analysis revealed that PD-L1 expression on CAFs was an independent prognostic factor of longer relapse-free survival after surgery (hazard ratio: 3.225, P = 0.027).

CONCLUSION

PD-L1 expression on CAFs is reversibly regulated by environmental stimuli including IFN-γ from activated lymphocytes. In the non-metastatic NSCLC, PD-L1 expression on CAFs suggests the induction of anti-tumor immune responses, contributing to better prognosis after surgery.

Impaired Tumor-Infiltrating T Cells in Patients with Chronic Obstructive Pulmonary Disease Impact Lung Cancer Response to PD-1 Blockade

RATIONALE

Patients with chronic obstructive pulmonary disease (COPD) have a higher prevalence of lung cancer. The chronic inflammation associated with COPD probably promotes the earliest stages of carcinogenesis. However, once tumors have progressed to malignancy, the impact of COPD on the tumor immune microenvironment remains poorly defined, and its effects on immune-checkpoint blockers' efficacy are still unknown.

OBJECTIVES

To study the impact of COPD on the immune contexture of non-small cell lung cancer.

METHODS

We performed in-depth immune profiling of lung tumors by immunohistochemistry and we determined its impact on patient survival (n = 435). Tumor-infiltrating T lymphocyte (TIL) exhaustion by flow cytometry (n = 50) was also investigated. The effectiveness of an anti-PD-1 (programmed cell death-1) treatment (nivolumab) was evaluated in 39 patients with advanced-stage non-small cell lung cancer. All data were analyzed according to patient COPD status.

MEASUREMENTS AND MAIN RESULTS

Remarkably, COPD severity is positively correlated with the coexpression of PD-1/TIM-3 (T-cell immunoglobulin and mucin domain-containing molecule-3) by CD8 T cells. In agreement, we observed a loss of CD8 T cell-associated favorable clinical outcome in COPD⁺ patients. Interestingly, a negative prognostic value of PD-L1 (programmed cell death ligand 1) expression by tumor cells was observed only in highly CD8 T cell-infiltrated tumors of COPD⁺ patients. Finally, data obtained on 39 patients with advanced-stage non-small cell lung cancer treated by an anti-PD-1 antibody showed longer progression-free survival in COPD⁺ patients, and also that the association between the severity of smoking and the response to nivolumab was preferentially observed in COPD⁺ patients.

CONCLUSIONS

COPD is associated with an increased sensitivity of CD8 tumor-infiltrating T lymphocytes to immune escape mechanisms developed by tumors, thus suggesting a higher sensitivity to PD-1 blockade in patients with COPD.

Indoleamine-2,3-Dioxygenase in Non-Small Cell Lung Cancer: A Targetable Mechanism of Immune Resistance Frequently Coexpressed With PD-L1

The immune regulatory enzyme indoleamine-2,3-dioxygenase (IDO-1) suppresses T cell responses and may reduce efficacy of therapies targeting immune checkpoints such as programmed death receptor-1/programmed death ligand-1 (PD-1/PD-L1). Early phase clinical trials combining IDO-1 and PD-1/PD-L1 inhibitors have shown some promise in non-small cell lung cancers (NSCLCs). However, the coexpression of IDO-1 and PD-L1 has not been thoroughly investigated, and the potential for IDO-1 immunohistochemical expression as a therapeutic biomarker is unknown. One hundred two cases of NSCLC (51 adenocarcinomas, 9 adenosquamous carcinomas, and 42 squamous cell carcinomas) were evaluated for IDO-1 and PD-L1 expression by immunohistochemistry. IDO-1 expression was identified in 43% of NSCLC (42% of adenocarcinomas, 44% of adenosquamous carcinomas, and 43% of squamous cell carcinomas). Coexpression with PD-L1 (≥1%) was common (27% overall; 27% of adenocarcinomas, 33% of adenosquamous carcinomas, and 26% of squamous cell carcinomas). A smaller population of tumors showed isolated PD-L1 (25% overall; 16% of adenocarcinomas, 44% of adenosquamous carcinomas, and 33% of squamous cell carcinomas) or IDO-1 expression (15% overall; 14% of adenocarcinomas, 11% of adenosquamous carcinomas, and 17% of squamous cell carcinomas). In summary, IDO-1 is commonly expressed by NSCLC, and its frequent coexpression with PD-L1 may account for the increased efficacy seen with dual blockade of PD-1/PD-L1 and IDO in clinical studies. IDO-1 immunohistochemistry may be a useful biomarker for selection of patients who could benefit from dual-agent therapy and should be evaluated in prospective clinical trials using PD-1/PD-L1 and IDO inhibitors.

Tumor-draining lymph nodes demonstrate a suppressive immunophenotype in patients with non-small cell lung cancer assessed by endobronchial ultrasound-guided transbronchial needle aspiration: A pilot study

OBJECTIVES

Tumor draining lymph nodes (TDLN) are key sites of early immunoediting in patients with non-small cell lung cancer (NSCLC) and play an important role in generating anti-tumor immunity. Immune suppression in the tumor microenvironment has prognostic implications and may predict therapeutic response. T cell composition of draining lymph nodes may reflect an immunophenotype with similar prognostic potential which could be measured during standard-of-care bronchoscopic assessment. In this study, we compared the immunophenotype from different sites within individuals to primary tumor characteristics in patients with NSCLC to see whether there were tumor-regional differences in immunophenotype which could be evaluated from transbronchial needle aspirates.

MATERIALS AND METHODS

Twenty patients were enrolled in this study and had tissue (lymph node aspirates and/or peripheral blood) obtained during standard of care bronchoscopy with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for diagnosis or staging of known or suspected NSCLC. Aspirates and blood underwent flow-assisted cell sorting and a subset of sorted effector T cells underwent RNA quantitation to determine feasibility of this approach. Immunophenotypic patterns from twelve patients with paired data from tumor-draining and non-tumor draining lymph nodes (NDLN) were compared relative to one another and based on PD-L1 immunohistochemistry and primary tumor histology.

RESULTS

TDLN had significantly fewer CD4⁺ T cells (12.68% vs 27%, p = 0.002) and significantly more regulatory T cells (Treg, 12.03% vs 9.52%, p = 0.03) relative to paired NDLN suggesting tumor-regional immunosuppression. There were significantly more Treg in NDLN relative to paired PBMC (9.52% vs 5.6%, p = 0.016). Patients with PD-L1 expression ≥50% had significantly greater tumor-regional CD4⁺ T cell depletion compared to patients with PD-L1 expression <50% (-35.98% vs -1.89%, p = 0.0357; negative values represent absolute difference between paired TDLN and NDLN).

CONCLUSIONS

In patients with NSCLC, TDLN have a suppressive immunophenotype correlating with tumor PD-L1 status and can be assessed during routine EBUS-TBNA.

Diagnostic Utility of PD-L1 Expression in Lung Adenocarcinoma: Immunohistochemistry and RNA In Situ Hybridization

BACKGROUND

Programmed death receptor and programmed death ligand (PD-L1) are immunoregulatory proteins. Nonsmall cell lung cancer bypasses the immune system through the induction of protumorigenic immunosuppressive changes. The better understanding of immunology and antitumor immune responses has brought the promising development of novel immunotherapy agents like programmed death receptor checkpoint inhibitors. The aim of this study was to investigate the expression of PD-L1 in lung adenocarcinoma (ADC), comparing 2 different technologies: immunohistochemistry (IHC) by 2 methods versus RNA in situ hybridization (RISH).

METHODOLOGY

In total, 20 cases of ADC of the lung and 4 samples of metastatic colon ADC were selected. Evaluation of PD-L1 expression was performed by IHC and RISH. RISH was performed using RNAscope. Both methods were scored in tumor cells and quantified using combined intensity and proportion scores.

RESULTS

Eight of 20 (40%) lung ADC and 2 of 4 (50%) colon ADC were positive for PD-L1 with Cell Signaling IHC, and 65% lung ADC were positive by Dako IHC (13/20). All 4 cases of colon ADC were negative. When evaluated by RISH, 12 lung ADC (60%) and 1 colon ADC (25%) were PD-L1 positive.

CONCLUSIONS

RNAscope probes provide sensitive and specific detection of PD-L1 in lung ADC. Both IHC methods (Cell Signaling and Dako) show PD-L1 expression, with the Dako method more sensitive (40% vs. 65%). This study illustrates the utility of RISH and Cell Signaling IHC as complementary diagnostic tests, and Food and Drug Administration approved Dako IHC as a companion diagnostic test.

Epidermal Growth Factor Receptor (EGFR) Pathway, Yes-Associated Protein (YAP) and the Regulation of Programmed Death-Ligand 1 (PD-L1) in Non-Small Cell Lung Cancer (NSCLC)

The epidermal growth factor receptor (EGFR) pathway is a well-studied oncogenic pathway in human non-small cell lung cancer (NSCLC). A subset of advanced NSCLC patients (15–55%) have EGFR-driven mutations and benefit from treatment with EGFR-tyrosine kinase inhibitors (TKIs). Immune checkpoint inhibitors (ICIs) targeting the PD-1/PDL-1 axis are a new anti-cancer therapy for metastatic NSCLC. The anti-PD-1/PDL-1 ICIs showed promising efficacy (~30% response rate) and improved the survival of patients with metastatic NSCLC, but the role of anti-PD-1/PDL-1 ICIs for EGFR mutant NSCLC is not clear. YAP (yes-associated protein) is the main mediator of the Hippo pathway and has been identified as promoting cancer progression, drug resistance, and metastasis in NSCLC. Here, we review recent studies that examined the correlation between the EGFR, YAP pathways, and PD-L1 and demonstrate the mechanism by which EGFR and YAP regulate PD-L1 expression in human NSCLC. About 50% of EGFR mutant NSCLC patients acquire resistance to EGFR-TKIs without known targetable secondary mutations. Targeting YAP therapy is suggested as a potential treatment for NSCLC with acquired resistance to EGFR-TKIs. Future work should focus on the efficacy of YAP inhibitors in combination with immune checkpoint PD-L1/PD-1 blockade in EGFR mutant NSCLC without targetable resistant mutations.

Immune checkpoints and cancer in the immunogenomics era

Immune checkpoints have been the subject of a wave of new studies. Among these checkpoints are tytotoxic T-lymphocyte-associated antigen 4, checkpoints programmed death-1 and programmed death-ligand 1; their blockades have been approved by the Food and Drug Administration for therapy of melanoma and other types of cancers. Immunogenomics, which combines the latest nucleic acid sequencing strategy with immunotherapy, provides precise information about genomic alterations (e.g. mutations) and enables a paradigm shift of immune checkpoint therapy from tumor types to molecular signatures. Studying these critical checkpoints in relation to genomic mutations and neoantigens has produced groundbreaking results. This article examines these studies and delves into the relationships between immune checkpoint blockade and tumors harboring certain genomic mutations. Moreover, this article reviews recent studies on resistance to immune checkpoint therapy.

Dynamic changes in PD-L1 expression and CD8+ T cell infiltration in non-small cell lung cancer following chemoradiation therapy

OBJECTIVES

The treatment for stage III non-small cell lung cancer (NSCLC) is quite variable because stage III NSCLC is a heterogenous disease. Programmed death ligand 1 (PD-L1) and CD8⁺ tumor infiltrating lymphocytes (TILs) are thought to be related to treatment outcome in many tumors. To improve treatment outcome in stage III NSCLC, it is necessary to obtain data on PD-L1 expression and CD8⁺ TIL counts following CCRT and their relationship to treatment outcome.

MATERIALS AND METHODS

We retrospectively enrolled 43 patients with stage III NSCLC treated with neoadjuvant CCRT followed by surgery at Yonsei Cancer Center Severance Hospital in Korea between June 2008 and October 2010. PD-L1 level and CD8⁺ TIL numbers in tumors following CCRT were analyzed by immunohistochemistry, and their association with patient survival was evaluated with Kaplan-Meier method.

RESULTS

More than half patients (52%) showed up- or downregulation of PD-L1 expression, and most patients (81%) showed change in CD8⁺ TIL counts by CCRT. Patients with PD-L1 expression following CCRT tended to have shorter recurrence free survival (RFS) (P = 0.182) or overall survival (OS) (P = 0.215) compared to the ones without PD-L1 expression. In the survival analysis with pre-CCRT specimens, neither RFS nor OS showed statistically significant differences. Patients with increased CD8⁺ TIL counts following CCRT regardless of pathological response strongly showed longer OS (median: not reached vs. 14.2 months for others; P = 0.017).

CONCLUSIONS

CCRT dynamically alters PD-L1 expression and CD8⁺ TIL numbers in stage III NSCLC. Our data provide a rationale for combining CCRT and immunotherapy for the treatment of potentially resectable NSCLC.

The clinicopathological and prognostic significance of PD-L1 expression assessed by immunohistochemistry in lung cancer: a meta-analysis of 50 studies with 11,383 patients

Background

We conducted a meta-analysis to systematically evaluate the relationship between programmed death-ligand 1 (PD-L1) expression and survival in patients with lung cancer.

Methods

The electronic databases PubMed, Embase, Cochrane, and Web of Science were searched up to January 2^nd, 2018, for articles relating to PD-L1 expression detected by immunohistochemistry (IHC) and lung cancer patient prognosis.

Results

Fifty studies including 11,383 patients published between 2011 and 2017 were enrolled in this meta-analysis. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) suggested that PD-L1 IHC expression was related to poor overall survival (OS) (HR =1.45, 95% CI: 1.24-1.68). In subgroup analysis categorized according to sample type, cut-off value, ethnicity and TNM stage, the pooled results demonstrated inferior survival in the PD-L1 positive group when the PD-L1 expression was detected by resection specimens (P=0.000), 5% was taken as the cutoff value (P=0.000), the patients were in early stage (I-III) (P=0.000), and the geographic setting of the study was in Asia (P=0.000). Besides, patients with high PD-L1 expression had shorter OS in NSCLC (P=0.000), ADC (P=0.000), SCC (P=0.353) and LELC (P=0.810), while no significant difference was observed in SCLC (P=0.000). The pooled odds ratios (ORs) suggested that PD-L1 expression was associated with male (P<0.001), smoker (P<0.001), poor tumor differentiation (P=0.014), large tumor size (P=0.132), positive lymph nodal metastasis (P=0.002), EGFR wild-type status (P<0.001) and KRAS mutations (P=0.393). However, age (P=0.15) and ALK rearrangements (P=0.567) had no bearing on PD-L1 expression.

Conclusions

PD-L1 expression that is associated with several clinicopathological feactures may serve as a poor prognostic biomarker for patients with lung cancer.