Changes in tumour expression of programmed death-ligand 1 after neoadjuvant concurrent chemoradiotherapy in patients with squamous oesophageal cancer

Primary small cell carcinoma of the esophagus: progression in the last decade

Primary small cell carcinoma of the esophagus (PSCCE) is a highly malignant tumor that is diagnosed by endoscopic biopsy and immunohistochemistry. Because of its low incidence, a high degree of malignancy, and rapid progress, it is difficult to conduct large, randomized controlled trials and to establish a standard treatment plan for this disease. In recent years, several retrospective studies have been reported, and with the rise of emerging therapies, PSCCE has gradually become a focus of thoracic surgery. This paper reviews progress in the diagnosis and treatment of PSCCE in recent years.

Changes in Indoleamine 2,3-Dioxygenase 1 Expression and CD8+ Tumor-Infiltrating Lymphocytes after Neoadjuvant Chemoradiation Therapy and Prognostic Significance in Esophageal Squamous Cell Carcinoma

PURPOSE

Despite good preclinical evidence, clinical data on the effect of neoadjuvant chemoradiation therapy (CRT) on expression of immune markers in esophageal cancer are limited. This study aimed to evaluate the changes in indoleamine 2,3-dioxygenase 1 (IDO1) expression, programmed cell death-ligand 1 (PD-L1) expression, and CD8+ tumor-infiltrating lymphocyte status after neoadjuvant CRT and the prognostic significance in esophageal squamous cell carcinoma (ESCC).

METHODS AND MATERIALS

Between 2003 and 2017, 138 patients with ESCC who underwent neoadjuvant CRT and esophagectomy without achieving pathologic complete response were included for analysis. Both pre-CRT biopsies and post-CRT surgical specimens were available in 82 patients. Immunohistochemistry of IDO1, PD-L1, and CD8 density were analyzed.

RESULTS

Among 82 paired samples, the expression levels of IDO1 and PD-L1 and CD8 density increased significantly after neoadjuvant CRT (P < .01 for all). Patients with high IDO1 expression after CRT had poorer overall survival (P = .001) and recurrence-free survival (P < .001) than those with low IDO1 expression. High post-CRT CD8 density was significantly correlated with more favorable overall survival (P = .01) and recurrence-free survival (P = .008). Neither pre- nor post-CRT PD-L1 expression was an independent prognostic factor for survival. Stratification analysis revealed that patients with combined low IDO1 expression and high CD8 density after CRT were significantly associated with better survival than other subgroups. The major findings were reproducible in an independent validation cohort.

CONCLUSIONS

IDO1 and PD-L1 expression and CD8 density increased significantly after neoadjuvant CRT in ESCC. The post-CRT IDO1 expression and CD8 density could serve as prognostic biomarkers for survival.

Hypofractionated radiation therapy with versus without immune checkpoint inhibitors in patients with brain metastases: A meta-analysis

INTRODUCTION

The efficacy and safety of hypofractionated radiation therapy (HFRT) combined with immune checkpoint inhibitors (ICIs) in patients with brain metastases (BM) remain controversial. This meta-analysis was performed to compare the efficacy and safety of HFRT with and without ICIs in BM patients.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane Library were searched up to 25 December 2018 for studies that compared the efficacy and safety of HFRT with and without ICIs in BM patients.

RESULTS

Twenty-four studies involving 2,365 patients were included in this analysis. Compared with those of HFRT without ICIs, the 6-month locoregional recurrence-free survival (LRFS) rate (P = 0.002), 6-month overall survival (OS) rate (P = 0.001), 1-year OS rate (P = 0.001), 2-year OS rate (P = 0.007), and median OS (mOS) (P < 0.001) were significantly improved in combined HFRT and ICI treatment. A trend toward improved 1-year LRFS rate (P = 0.392) and 3-year OS rate (P = 0.266) for the ICI arm was observed compared with the non-ICI arm, although there was no statistically significant difference between the two arms. No significant difference in toxicity was found between the two arms (radionecrosis: P = 0.361; BM hemorrhage: P = 0.738).

CONCLUSIONS

Compared with HFRT without ICIs, the combination of these two therapies improved efficacy but did not increase toxicity in patients with BM.

The prognostic value of B7-H6 in esophageal squamous cell carcinoma

B7-H6, a member of the B7 family molecules, participates in the clearance of tumor cells by binding to NKp30 on NK cells. B7-H6 expression level in esophageal squamous cell carcinoma (ESCC) and the clinical value remain unknown. The goal of this study was to determine the expression of B7-H6 in ESCC and further explore its clinical significance. We retrospectively collected the clinical data of 145 patients diagnosed with ESCC between January 2007 and December 2008. The expression of B7-H6 of the pathological tissue samples was detected by immunohistochemistry. The chi-square (χ²) test was used to analyse the relationships of B7-H6 and clinicopathological characteristics. Survival and hazard functions were estimated using the Kaplan-Meier method, and survival between groups was compared using the two-sided log-rank test. The Cox proportional hazards regression model was used to adjust for the risk factors related to overall survival (OS). 133/145 (91.72%) of the ESCC tissue samples exhibited B7-H6 expression. The expression level of B7-H6 was correlated with T stage (P = 0.036) and lymphatic metastasis status (P = 0.044). High B7-H6 expression (P = 0.003) was associated with a significantly worse OS than low B7-H6 expression. Multivariate Cox proportional hazards regression analysis demonstrated that tumour size (P = 0.021), B7-H6 expression (P = 0.025) and lymphatic metastasis status (P = 0.049) were independent prognostic factors of OS for ESCC. Collectively, our findings suggest that B7-H6 is widely expressed in ESCC samples. And B7-H6 may represent a predictor of poor prognosis for ESCC.

Assessing the interactions between radiotherapy and antitumour immunity

Immunotherapy, specifically the introduction of immune checkpoint inhibitors, has transformed the treatment of cancer, enabling long-term tumour control even in individuals with advanced-stage disease. Unfortunately, only a small subset of patients show a response to currently available immunotherapies. Despite a growing consensus that combining immune checkpoint inhibitors with radiotherapy can increase response rates, this approach might be limited by the development of persistent radiation-induced immunosuppression. The ultimate goal of combining immunotherapy with radiotherapy is to induce a shift from an ineffective, pre-existing immune response to a long-lasting, therapy-induced immune response at all sites of disease. To achieve this goal and enable the adaptation and monitoring of individualized treatment approaches, assessment of the dynamic changes in the immune system at the patient level is essential. In this Review, we summarize the available clinical data, including forthcoming methods to assess the immune response to radiotherapy at the patient level, ranging from serum biomarkers to imaging techniques that enable investigation of immune cell dynamics in patients. Furthermore, we discuss modelling approaches that have been developed to predict the interaction of immunotherapy with radiotherapy, and highlight how they could be combined with biomarkers of antitumour immunity to optimize radiotherapy regimens and maximize their synergy with immunotherapy.

Positive Programmed Cell Death-Ligand 1 Expression Predicts Poor Treatment Outcomes in Esophageal Squamous Cell Carcinoma Patients Receiving Neoadjuvant Chemoradiotherapy

Background: Programmed cell death-ligand 1 (PD-L1) is present in a subgroup of cancer patients who may be favorable targets for immune checkpoint inhibitor therapies. However, the significance of the PD-L1 expression in esophageal squamous cell carcinoma (ESCC) patients receiving neoadjuvant chemoradiotherapy remains unclear. Methods: By means of PD-L1 immunohistochemistry 22C3 pharmDx assay, we evaluate the PD-L1 expression and its association with clinical outcome in 107 ESCC patients receiving neoadjuvant chemoradiotherapy. Results: Patients with positive PD-L1 expression have significantly lower pathological complete response rates (13% versus 32%; p = 0.036) than those with negative PD-L1 expression. Univariate survival analysis found that positive PD-L1 expression were correlated with poor overall survival (p = 0.004) and inferior disease-free survival (p < 0.001). In a multivariate analysis, positive PD-L1 expression was independently associated with the absence of a pathologically complete response (p = 0.044, hazard ratio: 3.542), worse overall survival (p = 0.006, hazard ratio: 2.017), and inferior disease-free survival (p < 0.001, hazard ratio: 2.516). Conclusions: For patients with ESCC receiving neoadjuvant chemoradiotherapy, positive PD-L1 expression independently predicts the poor chemoradiotherapy response and worse treatment outcome. Thus, our data suggests that PD-L1 may be an influential biomarker for prognostic classification and for immune checkpoint inhibitor therapies in ESCC patients receiving neoadjuvant chemoradiotherapy.

High Stromal TGFBI in Lung Cancer and Intratumoral CD8-Positive T Cells were Associated with Poor Prognosis and Therapeutic Resistance to Immune Checkpoint Inhibitors

BACKGROUND

We investigated whether the expression of transforming growth factor-beta-induced protein (TGFBI) and intratumoral immune cells including CD8- and Forkhead box protein P3 (Foxp3)-positive T cells in clinical lung cancer patients could predict the therapeutic response to nivolumab.

METHODS

Thirty-three patients who were treated with nivolumab were enrolled in this study. Immunohistochemical analyses of TGFBI, PD-L1, CD8, Foxp3, and vimentin expression were conducted. Serum concentrations of TGFBI and transforming growth factor-beta1 (TGF-β1) were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Cancer TGFBI was not associated with prognosis and therapeutic response to nivolumab, but cancer stromal TGFBI and intratumoral CD8-positive T cells were associated with them. Therefore, we evaluated cancer stromal TGFBI and intratumoral CD8-positive T cells. The high-TGFBI-expression group had poorer clinical responses than did the low-TGFBI-expression group (p < 0.0001). The number of times nivolumab was administered in the high-CD8-expression group was significantly higher than that in the low-CD8-expression group (p = 0.0046). The high-CD8-expression group had better clinical responses than did the low-CD8-expression group (p = 0.0013). Interestingly, all patients in the high-TGFBI/low-CD8-expression group had progressive disease (PD). In contrast, all patients in the low-TGFBI/high-CD8-expression group had PR + SD (partial response + stable disease) by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1).

CONCLUSIONS

The dual evaluation of stromal TGFBI and intratumoral CD8-positive T cells could be a useful predictive marker for nivolumab.

Plasma Biomarkers and Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer: New Tools for Better Patient Selection?

Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape for patients with non-small cell lung cancer (NSCLC). Although some patients can experience important response rates and improved survival, many others do not benefit from ICIs developing hyper-progressive disease or immune-related adverse events. This underlines the need to select biomarkers for ICIs use in order to better select patients. There is currently no universally validated robust biomarker for daily use of ICIs. Programmed death-ligand 1 (PD-L1) or tumor mutational burden (TMB) are sometimes used but still have several limitations. Plasma biomarkers are a promising approach in ICI treatment. This review will describe the development of novel plasma biomarkers such as soluble proteins, circulating tumor DNA (ctDNA), blood TMB, and blood microbiome in NSCLC patients treated with ICIs and their potential use in predicting response and toxicity.

[Definitive or neo-adjuvant chemoradiation in esophageal carcinoma?]

Management of resectable esophageal carcinoma is based on a multimodal treatment associating neo-adjuvant chemoradiation before surgery. This therapeutic sequence allows a disease-free survival rate at 2 years around 45% but remains associated with a high post-operative morbidity. In case of definitive chemoradiotherapy, the dose delivered to the macroscopic disease is a controversial topic since decades and the prognosis of patients treated in this setting at the dose of 50Gy remains poor. This article proposes a review of the main published data and the ongoing studies related to the management of these patients.

Polymorphism of the programmed death-ligand 1 gene is associated with its protein expression and prognosis in gastric cancer

BACKGROUND AND AIM

While the incidence and mortality of gastric cancer (GC) remains high, and prognosis of GC remains poor, molecules in programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), and programmed death-ligand 2 (PD-L2) pathway are promising prognostic biomarker of GC. The polymorphisms on PD-1, PD-L1, and PD-L2 may be associated with their protein expressions and affect the survival of GC patient.

METHODS

Seven hundred fifty-six GC patients who voluntarily supplied blood samples were enrolled in our study. We genotyped nine polymorphisms on PD-1, PD-L1, and PD-L2, then evaluated the association of the single nucleotide polymorphisms with GC prognosis and analyzed the relationship between the PD-1, PD-L1, and PD-L2 single nucleotide polymorphism genotypes and their protein expression.

RESULTS

We found that PD-L1 rs822336 CC genotype was independently associated with a better survival of all GC patients and those without postoperative chemotherapy (hazard ratio [HR] = 0.504, 95% confidence interval [CI] = 0.283-0.897 and HR = 0.385, 95% CI = 0.189-0.786). AA+AG genotype of rs2297136 in 3'UTR of the PD-L1 was correlated with the protein expression of PD-L1 protein both in patients overall and those without postoperative chemotherapy (P = 0.013 and P = 0.012). AA+AG genotype of rs2297136 served as an independent factor of better prognosis in patients without postoperative chemotherapy (HR = 0.348, 95% CI = 0.125-0.968).

CONCLUSIONS

Overall, PD-L1 polymorphisms and protein expression were associated with the prognosis of patients with GC.

Novel circulating tumor cell-based blood test for the assessment of PD-L1 protein expression in treatment-naïve, newly diagnosed patients with non-small cell lung cancer

We evaluated the analytical and clinical performance of a novel circulating tumor cell (CTC)-based blood test for determination of programmed death ligand 1 (PD-L1) protein expression status in real time in treatment-naïve non-small cell lung cancer (NSCLC) patients. CTCs were detected in 86% of patients with NSCLC (I-IV) at the time of diagnosis, with a 67% PD-L1 positivity rate (≥ 1 PDL + CTC). Among 33 NSCLC patients with PD-L1 results available via both tissue immunohistochemistry (IHC) and CTC assays, 78.9% were positive according to both methods. The CTC test identified an additional ten cases that were positive for PD-L1 expression but that tested negative via IHC analysis. Detection of higher PD-L1 expression on CTCs compared to that in the corresponding tissue was concordant with data obtained using other platforms in previously treated patients. The concordance in PD-L1 expression between tissue and CTCs was approximately 57%, which is higher than that reported by others. In summary, evaluation of PD-L1 protein expression status on CTCs isolated from NSCLC patients is feasible. PD-L1 expression status on CTCs can be determined serially during the disease course, thus overcoming the myriad challenges associated with tissue analysis.

Negativation of PD-L1 Postoperatively in Initially Inoperable Stage III Non-Small Cell Lung Cancer Treated with Pembrolizumab: Two Case Reports

Stage III non-small cell lung cancer is a border line stage between localized and metastatic disease. PDL-1 is gaining an important role in the therapeutic arsenal of lung cancer, the most frequent cancer worldwide. We report for the first time a negativation of PDL-1 status in 2 cases of stage IIIA NSCLC with conversion to operable disease after using immunotherapy. The first patient was a 59-year old female diagnosed incidentally to have stage IIIA inoperable NSCLC that was treated with combination chemo-immunotherapy, and converted to operable disease with a negative PD-L1 in the postoperative setting. The second case is that of a 56-year old male that also had an inoperable stage IIIA NSCLC treated with chemotherapy first line followed by pembrolizumab at progression, then operated after surgical conversion, with negative PD-L1 postoperatively. In front of these findings, further work should be done to elucidate if the reverse of the PDL-1 status and the conversion to operability were due to the use of immunotherapy or to an incidental finding. If confirmed, it may have a therapeutic impact.

Paired whole exome and transcriptome analyses for the Immunogenomic changes during concurrent chemoradiotherapy in esophageal squamous cell carcinoma

BACKGROUND

The immunogenomic changes triggered by concurrent chemoradiation therapy (CCRT), a standard neoadjuvant treatment for locally advanced esophageal squamous cell carcinoma (ESCC), are unknown. We aimed to analyze the early immunogenomic changes in ESCC induced by CCRT and to correlate them with clinical outcomes.

METHODS

We collected biopsy samples from 40 patients with ESCC and the surgical candidates were treated with 5-fluorouracil (5-FU)/Cisplatin and concurrent radiation therapy. Endoscopic biopsy was performed before and after one treatment cycle of 5-FU/Cisplatin and 5 to 18 fractions of radiation. We analyzed immunogenomic changes using paired whole-exome sequencing (n = 29) and paired whole-transcriptome sequencing (WTS, n = 23). Multiplex immunohistochemistry (IHC) was conducted in four representative pair samples.

RESULTS

Fourteen out of 23 WTS samples (60.8%) showed increased immune scores after CCRT, as calculated by ESTIMATE. The rate of progression-free survival was higher in patients with increased immune scores compared with the remaining patients (83.1% vs. 57.1%, p = 0.25). Tumor mutation burden and neoantigen load were significantly reduced after CCRT (p < 0.001). We observed no specific correlation with non-synonymous mutations and no changes in the single-nucleotide variant spectrum after CCRT. Post-CCRT samples were enriched in gene sets related to immune signaling pathways, such as interferon gamma signaling and CD28 co-stimulation. Multiplex IHC showed an incremental trend in the proportion of CD4 positive cells in cytokeratin positive region after CCRT. However, CD8, CD20, FOXP1, PD-L1 showed no definitive trend. Proportion of immune cells calculated by CIBERSORT, showed that significant increase in neutrophils after CCRT.

CONCLUSIONS

We have comprehensively analyzed the early immunogenomic changes induced in ESCC by CCRT and correlated them with clinical outcomes. Our results provide a potential basis for combining immunotherapy with CCRT for the treatment of ESCC.

Programmed Death Ligand 1 (PD-L1) Expression in Epithelial Ovarian Cancer: A Comparison of Type I and Type II Tumors

Objective:

To examine the expression of programmed death ligand 1 (PD-L1) in type I and type II epithelial ovarian cancers (EOC) and its associations with outcomes.

Methods:

Records of 132 women with EOC were reviewed. Immunostaining of PD-L1 was performed with formalin-fixed, paraffin-embedded specimens. Expression of PD-L1 was classified into four categories (0; 1+; 2+; 3+) according to intensity of expression. Expression of PD-L1 ≥2+ was deemed to be high.

Results:

Of the 132 women, 75 (56.8%) and 57 (43.2%) women had type I and type II tumors, respectively. Approximately 70% of cases exhibited high PD-L1 expression. There was no significant difference in the rate of high PD-L1 expression between the two EOC types (65.3% versus 59.6%). In type I tumors, high PD-L1 expression was associated with more advanced stages (51.0% versus 34.6%), greater recurrence (46.9% versus 26.9%), and shorter median progression-free survival (27 months versus 62 months) than low expression. In type II tumors, there were no apparent differences between high and low expression of PD-L1 in terms of the percentage of advanced-stage tumors (82.6% versus 79.4%), recurrence (56.5% versus 58.8%), and median progression-free survival (21 months versus 24 months).

Conclusion:

high PD-L1 expression is associated with worse oncological outcomes in type I EOC. This finding emphasizes the merit of further studies to confirm this promising result and to determine the potential role of PD-L1 blockade therapy in type I EOC.

Combining Radiation and Immune Checkpoint Blockade in the Treatment of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a significant cause of morbidity and mortality worldwide. Current treatment options, even though potentially curative, have many limitations including a high rate of complications. Over the past few years immune checkpoint inhibitors (ICI) targeting cytotoxic lymphocyte antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death ligand 1 (PD-L1) have changed treatment paradigms in many malignancies and are currently under investigation in HNSCC as well. Despite improvements in treatment outcomes and the implementation of combined modality approaches long-term survival rates in patients with locally advanced HNSCC remain suboptimal. Accumulating evidence suggests that under certain conditions, radiation may be delivered in conjunction with ICI to augment efficacy. In this review, we will discuss the immune modulating mechanisms of ICI and radiation, how changing the dose, fractionation, and field of radiation may alter the tumor microenvironment (TME), and how these two treatment modalities may work in concert to generate durable treatment responses against HNSCC.

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

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

Upregulation of tumor PD-L1 by neoadjuvant chemoradiotherapy (neoCRT) confers improved survival in patients with lymph node metastasis of locally advanced rectal cancers

The expression of programmed cell death 1 ligand 1 (PD-L1) and interferon-γ (IFN-γ) is of great interest for the development of chemoradiotherapy and immune checkpoint inhibitor treatments. Patients with nodal metastasis (pN+) tend to have a poor prognosis, even after neoadjuvant chemoradiotherapy (neoCRT) and surgical treatment. In this study, we examined the roles of tumor PD-L1 and IFN-γ before and after neoCRT in locally advanced rectal cancer (LARC) patients. Our results demonstrate that patients with high PD-L1 expression in post-neoCRT tissues exhibit improved 5-year disease-free survival (DFS) and overall survival (OS) compared with those with low PD-L1 expression (p < 0.001). Furthermore, in the pN+ population, patients with high PD-L1 expression in post-neoCRT tissues exhibit improved 5-year DFS and OS. PD-L1 and IFN-γ upregulation increased in tumor tissues after neoCRT, and patients with high PD-L1 and high IFN-γ exhibit improved 5-year DFS and OS (p = 0.04 and p = 0.001, respectively). To the best of our knowledge, this study is the first to demonstrate that PD-L1 upregulation in a pN+ cohort correlates with improved prognosis, which is similar to that in patients without nodal metastasis. Moreover, this study verified that PD-L1 and IFN-γ were upregulated by neoCRT treatment in LARC patients and demonstrated that neoCRT may be useful not only for immune checkpoint inhibitor treatment but also for reinvigorating preexisting anti-cancer immunity.

Indoleamine 2,3-dioxygenase 1 and Programmed Cell Death-ligand 1 Co-expression Predicts Poor Pathologic Response and Recurrence in Esophageal Squamous Cell Carcinoma after Neoadjuvant Chemoradiotherapy

This study aimed to investigate the impact of indoleamine 2,3-dioxygenase 1 (IDO1) expression, programmed cell death-ligand 1 (PD-L1) expression, CD8+ tumor-infiltrating lymphocyte (TIL) status, and their combination on pathologic complete response (pCR) and recurrence in esophageal squamous cell carcinoma (ESCC) treated with neoadjuvant chemoradiotherapy (CRT). Indoleamine 2,3-dioxygenase 1, PD-L1, and CD8+ TIL statuses were evaluated by immunohistochemical analysis on pre-CRT biopsies of 158 patients. Sixty-eight patients (43.0%) achieved pCR after neoadjuvant CRT and 48 patients (30.4%) developed recurrences after surgery. IDO1 and PD-L1 proteins were co-expressed in 28 patients (17.7%). Indoleamine 2,3-dioxygenase 1 positive patients showed a significantly lower pCR rate than IDO1 negative patients (28.6% vs. 51.0%, P = 0.007). Similarly, PD-L1 high expression was significantly negatively correlated with pCR rate (27.3% vs. 51.5%, P = 0.004). On multivariate analysis, IDO1 expression was an independent prognostic factor for developing recurrences. Stratification analysis revealed that patients with co-expression of IDO1 and PD-L1 were significantly associated with a lower pCR rate and worse recurrence-free survival than those with one or none positive protein. In conclusion, IDO1 and PD-L1 co-expression could predict poor pathologic response and high risk of recurrence in ESCC after neoadjuvant CRT, indicating a subset of patients who may benefit from CRT combined with immunotherapy.

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

Background

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

Methods

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

Results

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

Conclusions

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

Discordancy and changes in the pattern of programmed death ligand 1 expression before and after platinum-based chemotherapy in metastatic gastric cancer

BACKGROUND

Our goal was to evaluate changes in PD-L1 expression in primary tumours of metastatic gastric cancer before and after chemotherapy.

METHODS

We evaluated the PD-L1 expression of 72 patients with primary gastric cancer, before and after palliative first-line platinum-based chemotherapy, between January 2015 and March 2017. The PD-L1 ratio was defined as pre-chemotherapy PD-L1 expression divided by the post-chemotherapy PD-L1 expression.

RESULTS

In 30 patients with PD-L1 negative pre-chemotherapy, 12 (40%) were positive post-chemotherapy; among the 42 patients with PD-L1 positive pre-chemotherapy, 24 (57.1%) were negative post-chemotherapy. The degree of PD-L1 expression decreased from 58.3% before chemotherapy to 41.7% after chemotherapy (P = 0.046). Among patients with complete response/partial response (CR/PR), the degree of PD-L1 expression decreased (P = 0.002), as well as PD-L1 positivity with statistical significance (P = 0.013) after chemotherapy, but not among patients with stable disease/progressive disease (SD/PD). Higher disease control rates (CR/PR/SD) were observed in patients with an elevated PD-L1 ratio (P = 0.043). Patients with a high PD-L1 ratio (> 1) were found to be associated with a better progression-free survival (HR 0.34, 95% CI 0.17-0.67, P = 0.002).

CONCLUSIONS

PD-L1 expression can change during chemotherapy. Moreover, changes in patterns of PD-L1 expression might be associated with patient prognosis and response to chemotherapy.

High PD-L1 expression is associated with a favorable prognosis in patients with esophageal squamous cell carcinoma undergoing postoperative adjuvant radiotherapy

Previous results on the prognostic value of programmed death-ligand (PD-L)1 expression in patients with esophageal squamous cell carcinoma (ESCC) remain limited and conflicting. The present study aimed to determine whether PD-L1 expression status predicts prognosis in patients with ESCC, particularly in those undergoing different postoperative treatments. Immunohistochemical staining for PD-L1 was performed on surgical specimens that were obtained from 246 patients with ESCC, who underwent surgical treatment but did not undergo preoperative chemotherapy, radiotherapy, targeted therapy or immune therapy. The association of PD-L1 expression with the clinicopathological factors and the association of PD-L1 expression with survival of patients with ESCC, including subgroups of patients undergoing different postoperative treatments (surgery alone, surgery with adjuvant chemotherapy, surgery with adjuvant radiotherapy and surgery with adjuvant chemo-radiotherapy groups), were statistically analyzed. Positive PD-L1 expression was significantly associated with advanced tumor-node metastasis stage (P=0.022). Median overall survival (OS) time was compared between patients with positive PD-L1 expression and those with negative PD-L1 expression in the overall patient population. In patients who were treated with postoperative adjuvant radiotherapy, the prognosis was significantly improved in patients who were PD-L1-positive compared with those who were PD-L1-negative (P=0.046). In patients treated with adjuvant chemotherapy, median OS was poorer in patients with positive PD-L1 expression compared with those with negative PD-L1 expression. However, the difference was not significant. Multivariate Cox regression analysis demonstrated that PD-L1 expression status was not an independent prognostic factor in patients with ESCC. High PD-L1 expression was associated with a favorable prognosis in patients with ESCC undergoing postoperative adjuvant radiotherapy, and it was concluded that patients with positive PD-L1 expression might benefit from postoperative adjuvant radiotherapy.

PD-L1 microSPECT/CT Imaging for Longitudinal Monitoring of PD-L1 Expression in Syngeneic and Humanized Mouse Models for Cancer

Antibodies that block the interaction between programmed death ligand 1 (PD-L1) and PD-1 have shown impressive responses in subgroups of patients with cancer. PD-L1 expression in tumors seems to be a prerequisite for treatment response. However, PD-L1 is heterogeneously expressed within tumor lesions and may change upon disease progression and treatment. Imaging of PD-L1 could aid in patient selection. Previously, we showed the feasibility to image PD-L1⁺ tumors in immunodeficient mice. However, PD-L1 is also expressed on immune cell subsets. Therefore, the aim of this study was to assess the potential of PD-L1 micro single-photon emission tomography/computed tomography (microSPECT/CT) using radiolabeled PD-L1 antibodies to (i) measure PD-L1 expression in two immunocompetent tumor models (syngeneic mice and humanized mice harboring PD-L1 expressing immune cells) and (ii) monitor therapy-induced changes in tumor PD-L1 expression. We showed that radiolabeled PD-L1 antibodies accumulated preferentially in PD-L1⁺ tumors, despite considerable uptake in certain normal lymphoid tissues (spleen and lymph nodes) and nonlymphoid tissues (duodenum and brown fat). PD-L1 microSPECT/CT imaging could also distinguish between high and low PD-L1-expressing tumors. The presence of PD-L1⁺ immune cells did not compromise tumor uptake of the human PD-L1 antibodies in humanized mice, and we demonstrated that radiotherapy-induced upregulation of PD-L1 expression in murine tumors could be monitored with microSPECT/CT imaging. Together, these data demonstrate that PD-L1 microSPECT/CT is a sensitive technique to detect variations in tumor PD-L1 expression, and in the future, this technique may enable patient selection for PD-1/PD-L1-targeted therapy.

The use of cytological material in melanoma for programmed death ligand 1 immunostaining

OBJECTIVE

Interest in immune therapies has exploded since the 2014 approval of first-generation programmed cell death 1 blocking antibodies for use in advanced melanoma. Clinical trials have focused primarily on histological material as the gold standard for evaluating programmed death ligand 1 (PD-L1) by immunoperoxidase (IPOX) studies. Studies validating the use of cytological specimens in the assessment of PD-L1 by IPOX staining are needed to optimise tissue utilisation in complementary diagnostic testing.

METHODS

Twenty-three melanoma surgical biopsies (SBx) with an IPOX stain for PD-L1 clone 28-8, and a corresponding cytological specimen from the same patient, adequate for PD-L1 evaluation, were selected. Cell-transfer cell blocks (CBs) and conventional CBs were used to perform PD-L1 testing. Tumour proportion scores (TPS) were generated and the results were correlated with the corresponding SBx.

RESULTS

Overall agreement (OA) using a ≥1% TPS cut-off for SBx compared to CB was 88.9%, positive percent agreement (PPA) was 87.5%, and negative percent agreement (NPA) was 100%, OA using a ≥5% TPS cut-off was 55.6%, PPA was 42.9%, and NPA was 100%. SBx compared to cell-transfer CB using a ≥1% TPS cut-off had an OA of 65.2%, a PPA of 55.6%, and a NPA of 100%, while a ≥5% TPS cut-off generated an OA of 52.2%, a PPA of 35.7%, and a NPA of 77.8%.

CONCLUSION

Our results demonstrate that cytological material, particularly conventional CB, is a viable alternative for evaluating PD-L1 in melanoma cases and suggest that a lower threshold (≥1%) may be beneficial when evaluating cytological material.

Clinical significance of programmed death 1 ligand-1 (CD274/PD-L1) and intra-tumoral CD8+ T-cell infiltration in stage II-III colorectal cancer

Programmed cell death-1 (PDCD1/PD-1) and its ligand programmed cell death 1 ligand 1 (CD274/PD-L1) have been reported to suppress anti-tumor T cell-mediated immune responses. However, the clinical significance of CD274 in colorectal cancer were still elusive. We aim to clarify the relationships between CD8+ intratumor-infiltrating lymphocytes (TILs) and CD274 as well as their prognostic values in stage II-III colon carcinoma. Tumor differentiation, perineural invasion (PNI), pN stage and DNA mismatch repair (MMR)-deficient were clearly correlated with CD8+ TILs counts within the tumor microenvironment (p < 0.0001). Furthermore, tumor differentiation and PNI were suggestively correlated with tumor CD274 expression (p = 0.02 and p = 0.0195). Tumor CD274 level was significantly correlated with higher CD8+ TILs (p < 0.0001) but was not associated with MMR-deficient status (p = 0.14). High tumor CD274 expression [hazard ratio (HR) = 2.16, 95% CI = 1.63-2.86, p < 0.0001] and CD8+ TILs [HR = 1.51, 95% CI = 1.19-1.91, p = 0.0007] were associated with improved disease-free survival and overall survival. Additionally, the subgroup of patients who had a high CD8+ TILs/tumor CD274 have better survival outcomes compared with other subgroups (71% vs 53%; p < 0.0001). Therefore, the CD8+ TILs counts and tumor CD274 may be prognostic factors to predict survival and therapeutic responses in stage II-III colon carcinoma patients.

Dynamics of Soluble Programmed Death-Ligand 1 (sPDL1) during Chemotherapy and Its Prognostic Implications in Cancer Patients: Biomarker Development in Immuno-oncology

Purpose

The soluble programmed death-ligand 1 (sPDL1) has immunosuppressive activity and is a candidate biomarker for immuno-oncology drug development. In this study, we measured sPDL1 at pre- and post-chemotherapy and at disease progression to uncover the dynamics of sPDL1 during treatment in biliary tract cancer (BTC) patients.

Materials and Methods

From 90 BTC patients (training cohort, 53; validation cohort, 37) who were candidates for palliative first-line chemotherapy, blood was collected at pre- and post-chemotherapy (at the time of best response) and at disease progression. The sPDL1 levels were measured using an enzyme-linked immunosorbent assay. Responses to chemotherapy, overall survival (OS), and other prognostic factors including the neutrophil-lymphocyte ratio (NLR) were analyzed.

Results

The OS of all patients was 11.5 months (confidence interval [CI], 9.7 to 16.2). The best response was complete response in seven (7.8%), partial response in 20 (22.2%), stable disease in 52 (57.8%), and disease progression (PD) in 11 patients (12.2%). Patients with high pre-chemotherapy sPDL1 (≥ 1.30 ng/mL) showed worse OS than patients with low prechemotherapy sPDL1 (9.1 months vs. 12.5 months, p=0.003). In multivariate analyses, high pre-chemotherapy sPDL1 (hazard ratio [HR], 1.96; 95% CI, 1.2 to 3.9; p=0.011) and high pre-chemotherapy NLR (HR, 1.82; 95% CI, 1.1 to 3.0; p=0.020) were independent poor prognostic factors for OS. At the time of PD, sPDL1 was increased significantly compared with pre-chemotherapy sPDL1 (1.59 ng/mL vs. 0.72 ng/mL, p=0.003).

Conclusion

The sPDL1 at pre-chemotherapy confers the prognostic value for OS in BTC patients under palliative chemotherapy. The dynamics of sPDL1 during chemotherapy correlate with disease burden and have prognostic value.

Dual TGF-β and PD-1 blockade synergistically enhances MAGE-A3-specific CD8+ T cell response in esophageal squamous cell carcinoma

PD-1 is highly expressed on tumor-infiltrated antigen-specific T cells and limit the antitumor function. Blocking of PD-1/PD-L1 signaling has shown unprecedented curative efficacies in patients with advanced cancer. However, only a limited population of patients benefited from such therapies. Our study aimed to explore biological properties, functional regulation and reversal of MAGE-A3-specific CD8⁺ T cells in patients with esophageal squamous cell carcinoma (ESCC). The underlying principle of deficiency and restoring MAGE-A3-specific CD8⁺ T cells function in tumor microenvironment (TME) was evaluated. MAGE-A3-specific CD8⁺ T cells could lyse HLA-A2⁺ /MAGE-A3⁺ tumor cells. Tetramer⁺ T cell frequency was higher in elder patients, but lower in patients with lymph node metastasis and late tumor stage (p < 0.05). CD107a^high expression on functional T cells was an independent prognostic factor in Cox regression analysis. PD-1 was highly expressed on dysfunctional antigen-specific CD8⁺ T cells and tumor infiltrating T lymphocytes (p < 0.05). Myeloid-derived suppressor cells (MDSCs) derived-TGF-β mediated PD-1^high expression on CD8⁺ T cells, which led to be resistance to PD-1/PD-L1 blockade in TME. Dual PD-1/PD-L1 and TGF-β signaling pathway blockades synergistically restored the function and antitumor ability of antigen-specific CD8⁺ T cells in vitro/vivo assay. The presence of functional MAGE-A3-specific CD8⁺ T cells had an independent prognostic impact on survival of patients with ESCC. Furthermore, MDSCs-derived TGF-β increased PD-1 expression on T cells and decreased the sensitivity to PD-1/PD-L1 blockade. Combining T cell-based therapy with dual PD-1/PD-L1 and TGF-β signaling pathway blockade could be considered a promising strategy for cancer treatment.

Clinical predictors of pathologically response after neoadjuvant chemoradiotherapy for esophageal squamous cell carcinoma: long term outcomes of a phase II study

Background

A pathologically complete response (pCR) or near pCR to neoadjuvant chemoradiotherapy (NCRT) might imply a better prognosis in patients with esophageal cancer. The aim of the study is to identify clinical factors associated with a pCR or near pCR.

Methods

We retrospectively analyzed 40 patients with radical esophagectomy after NCRT for esophageal squamous cell carcinoma (ESCC) from January 2001 to December 2006 in Sun Yat-sen University Cancer Center. Clinical factors included age, gender, weight loss, dysphagia, drinking status, smoking status, tumor location, tumor length, tumor grade, cT status, cN status, the regimen of chemotherapy and the interval between NCRT and surgery as potential predictors for a pCR or near pCR. Logistic regression was used to estimate the independent factors for a pCR or near pCR.

Results

After surgical resection, 22.5% of the patients obtained the pCR. Patients with pCR had a better prognosis than those with non-pCR. However, there was no statistically significantly difference between the two groups (P=0.124). We separated the patients into pCR or near pCR (good responders, GRs) and poor responders (PR) based on the histology. GR showed better overall survival (OS) than PR (P=0.014). Univariate analysis indicated that short tumor length, good tumor grade and never drinking were associated with GR to NCRT. Using logistic regression analysis, good tumor grade was the only independent factor for the GR to NCRT (P=0.021). Cox regression revealed that weight loss, drinking status and GR were independent factors in ESCC patients with radical esophagectomy after NCRT.

Conclusions

Our study indicated that good tumor grade were an independent significant factor for the GR to NCRT. Weight loss, drinking status and GR were independent factors in patients with radical esophagectomy after NCRT. GR may improve OS of ESCC patients receiving NCRT.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Background

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

Methods

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

Results

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

Conclusions

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

The Integration of Radiotherapy with Immunotherapy for the Treatment of Non-Small Cell Lung Cancer

Five-year survival rates for non-small cell lung cancer (NSCLC) range from 14% to 49% for stage I to stage IIIA disease, and are <5% for stage IIIB/IV disease. Improvements have been made in the outcomes of patients with NSCLC due to advancements in radiotherapy (RT) techniques, the use of concurrent chemotherapy with RT, and the emergence of immunotherapy as first- and second-line treatment in the metastatic setting. RT remains the mainstay treatment in patients with inoperable early-stage NSCLC and is given concurrently or sequentially with chemotherapy in patients with locally advanced unresectable disease. There is emerging evidence that RT not only provides local tumor control but also may influence systemic control. Multiple preclinical studies have demonstrated that RT induces immunomodulatory effects in the local tumor microenvironment, supporting a synergistic combination approach with immunotherapy to improve systemic control. Immunotherapy options that could be combined with RT include programmed cell death-1/programmed cell death ligand-1 blockers, as well as investigational agents such as OX-40 agonists, toll-like receptor agonists, indoleamine 2,3-dioxygenase-1 inhibitors, and cytokines. Here, we describe the rationale for the integration of RT and immunotherapy in patients with NSCLC, present safety and efficacy data that support this combination strategy, review planned and ongoing studies, and highlight unanswered questions and future research needs.

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

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

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

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

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

Programmed Death Ligand 1: A Step Toward Immunoscore for Esophageal Cancer

BACKGROUND

This study sought to evaluate the effect of tumor-infiltrating lymphocyte (TIL) density and programmed death ligand 1 (PD-L1) expression on the prognosis of esophageal cancer.

METHODS

Banked tissue specimens from 53 patients who underwent esophagectomies for malignancy at a single institution over a 6-year period were stained for cluster of differentiation 3 (CD3), CD8, and PD-L1. Tumors were characterized as staining high or low density for CD3 and CD8, as well as positive or negative for PD-L1. TIL density and PD-L1 expression were analyzed in the context of survival, recurrence, and perioperative characteristics.

RESULTS

Median follow-up was 823 days, with 92.5% survival and 26.8% recurrence rates. All tumors were adenocarcinomas. Neoadjuvant chemotherapy was given in 56.6% of cases, and neoadjuvant radiotherapy was given in 37.7%. High CD3 density was found in 83%, whereas high CD8 density was found in 56.6%. A total of 18.9% of the tumors stained positive for PD-L1. Survival was significantly shorter in Kaplan-Meier analysis for patients with primary tumors staining positive for PD-L1 (log rank: p = 0.05). Multivariable analysis controlling for neoadjuvant therapy, TIL markers, PD-L1, age, and sex found no significant difference in recurrence or survival.

CONCLUSIONS

Positive staining for PD-L1 may be a prognostic marker for decreased survival in esophageal adenocarcinoma. Additional TIL cell types should be investigated for creation of an esophageal cancer Immunoscore. PD-L1 has potential as a therapeutic target.

Immunohistochemical expression and prognostic value of PD-L1 in Extrapulmonary small cell carcinoma: a single institution experience

BACKGROUND

Extrapulmonary small cell carcinomas (ESCC) are rare but aggressive tumors. Relapses are common despite treatment with chemotherapy and/or radiotherapy. Prospective data for treatment of ESCC are lacking; treatment of these cancers usually incorporates lung small cell carcinoma treatment recommendations. Cancer staging remains the most important prognostic factor. Cancer immunotherapy targeting the PD-1/PD-L1 pathway has shown efficacy in multiple tumor types, and could be an appealing treatment strategy for these rare tumors.

METHODS

We investigated PD-L1 expression by immunochemistry (IHC) in ESCCs diagnosed at University of Massachusetts Medical Center, from 1999 to 2016. 34 cases with sufficient material were selected for PD-L1 IHC analysis using clone E1L3N. PD-L1 expression was evaluated using the combined positive score (CPS). Retrospective chart review was performed. We evaluated the incidence and prognostic value of PD-L1 expression in ESCC at our institution.

RESULTS

Twelve out 34 cases (35%) had PD-L1 CPS scores ≥1. Ten cases had CPS scores ranging 1-5, whereas 2 cases had CPS scores > 80. The overall response rate to the standard chemotherapy with/without radiotherapy in the PD-L1 positive group was 80% versus 67% for the PDL-1 negative group (p-value 0.67). The median overall survival for the PD-L1 positive group, regardless of stage, was 11.5 months versus 7 months for PD-L1 negative group (p-value 0.34). Patients with limited stage disease with positive PD-L1 had a median survival of 53 months compared to 15 months for patients with PD-L1 negative limited stage (p-value 0.80).

CONCLUSIONS

This study showed that at least one third of our ESCC tissue samples expressed PD-L1. There was a trend for higher response rates to the standard chemotherapy with/without radiotherapy and improved survival in PD-L1 positive patients. Further studies are required to understand the implications of immune dysregulation in these aggressive tumors. PD-L1/PD-1 inhibitors should be investigated in this group of patients.

Predictive role of plasmatic biomarkers in advanced non-small cell lung cancer treated by nivolumab

Immune checkpoint inhibitors, as nivolumab, are used in advanced non-small cell lung cancer (NSCLC). However, no associated biomarker is validated in clinical practice with this drug. We investigated herein immune-related blood markers in patients with advanced NSCLC treated with nivolumab. Plasma of 43 consecutive patients were prospectively collected at time of the diagnosis of cancer, at the initiation of nivolumab and at the first tumour evaluation (2 months). Concentrations of PD-L1 (sPD-L1), soluble PD-L2 (sPD-L2), Interleukine-2 (sIl-2), Interferon-gamma (sIFN-γ), and Granzyme B (sGranB) were quantified by ELISA. Cell free RNA was quantified by Reverse Transcriptase -PCR), and plasmatic microRNAs (miRNAs) were evaluated by targeted sequencing. Expression of PD-L1 on tumour biopsies was performed by immunohistochemistry using E13LN. High sPD-L1 at 2 months and increase of sPD-L1 concentrations were associated with poor response and absence of clinical benefit (nivolumab treatment less than 6 months). The variation of sPD-L1 concentrations were confirmed by RNA quantification. sPD-L1 concentrations were not correlated with PD-L1 expression on corresponding tumour samples. Low sGranB at nivolumab initiation was also associated with poor response. High sPD-L1 and low sGranB were associated with poor progression-free survival (PFS) and overall survival (OS). Low sPD-L2, low sIl-2 and high sIFN-γ were associated with grade 3-4 toxicities. Finally, miRNA screening showed that patients with clinical benefit (n = 9) had down-expression of miRNA-320b and -375 compared to patients with early progression at 2 months (n = 9). In conclusion, our results highlight the interest of circulating biomarkers in patients treated with nivolumab.

Modulating PD-L1 expression in multiple myeloma: an alternative strategy to target the PD-1/PD-L1 pathway

Even with recent advances in therapy regimen, multiple myeloma patients commonly develop drug resistance and relapse. The relevance of targeting the PD-1/PD-L1 axis has been demonstrated in pre-clinical models. Monotherapy with PD-1 inhibitors produced disappointing results, but combinations with other drugs used in the treatment of multiple myeloma seemed promising, and clinical trials are ongoing. However, there have recently been concerns about the safety of PD-1 and PD-L1 inhibitors combined with immunomodulators in the treatment of multiple myeloma, and several trials have been suspended. There is therefore a need for alternative combinations of drugs or different approaches to target this pathway. Protein expression of PD-L1 on cancer cells, including in multiple myeloma, has been associated with intrinsic aggressive features independent of immune evasion mechanisms, thereby providing a rationale for the adoption of new strategies directly targeting PD-L1 protein expression. Drugs modulating the transcriptional and post-transcriptional regulation of PD-L1 could represent new therapeutic strategies for the treatment of multiple myeloma, help potentiate the action of other drugs or be combined to PD-1/PD-L1 inhibitors in order to avoid the potentially problematic combination with immunomodulators. This review will focus on the pathophysiology of PD-L1 expression in multiple myeloma and drugs that have been shown to modulate this expression.

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

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

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

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

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

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

Programmed death ligand 1 expression in esophageal cancer following definitive chemoradiotherapy: Prognostic significance and association with inflammatory biomarkers

Immunotherapy with anti-programmed cell death protein 1 or programmed death ligand 1 (PD-L1) agents has demonstrated promising efficacy for the treatment of various types of malignancies. However, the role of PD-L1 as a tumor prognostic marker remains poorly understood. In the present study, the prognostic value of PD-L1 expression in esophageal carcinoma (EC) following definitive chemoradiotherapy (CRT) was investigated, and its associations with three systemic inflammation biomarkers, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR) were further explored. A total of 104 patients with non-metastatic EC, who underwent definitive CRT between January 2009 and December 2012, were retrospectively analyzed. The expression of PD-L1 was examined by immunohistochemistry and the impact of PD-L1 expression level on overall survival (OS) was assessed. Furthermore, pretreatment neutrophil, lymphocyte, platelet and monocyte counts were obtained from routine blood tests to calculate the NLR, PLR and LMR. PD-L1 was overexpressed in EC compared with normal esophageal epithelium, with a positive expression rate of 37.5%. Additionally, patients with positive PD-L1 expression had a lower NLR than those with negative PD-L1 expression (P=0.001). On multivariate analysis, the positive staining of PD-L1 was significantly associated with improved OS (HR, 0.6; 95% CI, 0.372–0.965; P=0.035). Kaplan-Meier survival analysis showed a similar result (P=0.009). Additionally, sex (HR, 0.449; 95% CI, 0.229–0.880; P=0.020), clinical stage III (HR, 2.471; 95% CI, 1.171–5.212; P=0.018), and receipt of concurrent chemoradiation (HR, 0.590; 95% CI, 0.368–0.945; P=0.028) were all independent prognostic factors in EC treated with definitive CRT. The correlation of NLR with PD-L1 expression validated the relevance of immunity and inflammation. In summary, the present study demonstrated that positive PD-L1 expression is associated with improved survival in patients with EC treated with radical CRT, indicating that PD-L1 is a promising prognostic marker.

Safety of Combined PD-1 Pathway Inhibition and Intracranial Radiation Therapy in Non-Small Cell Lung Cancer

INTRODUCTION

Intracranial metastases are a common cause of morbidity and mortality in patients with advanced NSCLC, and are frequently managed with radiation therapy (RT). The safety of cranial RT in the setting of treatment with immune checkpoint inhibitors (ICIs) has not been established.

METHODS

We identified patients with advanced NSCLC with brain metastases who received cranial RT and were treated with or without programmed cell death 1/programmed death ligand 1 inhibitors between August 2013 and September 2016. RT-related adverse events (AEs) were retrospectively evaluated and analyzed according to ICI treatment status, cranial RT type, and timing of RT with respect to ICI.

RESULTS

Of 163 patients, 50 (31%) received ICIs, whereas 113 (69%) were ICI naive. Overall, 94 (58%), 28 (17%), and 101 (62%) patients received stereotactic radiosurgery, partial brain irradiation, and/or whole brain RT, respectively. Fifty percent of patients received more than one radiation course. We observed no significant difference in rates of all-grade AEs and grade 3 or higher AEs between the ICI-naive and ICI-treated patients across different cranial RT types (grade ≥3 AEs in 8% of ICI-naive patients versus in 9% of ICI-treated patients for stereotactic radiosurgery [p = 1.00] and in 8% of ICI-naive patients versus in 10% of ICI-treated patients for whole brain RT [p = 0.71]). Additionally, there was no difference in AE rates on the basis of timing of ICI administration with respect to RT.

CONCLUSIONS

Treatment with an ICI and cranial RT was not associated with a significant increase in RT-related AEs, suggesting that use of programmed cell death 1/programmed death ligand 1 inhibitors in patients receiving cranial RT may have an acceptable safety profile. Nonetheless, additional studies are needed to validate this approach.

Chemoradiation-Induced Alteration of Programmed Death-Ligand 1 and CD8+ Tumor-Infiltrating Lymphocytes Identified Patients With Poor Prognosis in Rectal Cancer: A Matched Comparison Analysis

PURPOSE

To evaluate chemoradiotherapy (CRT)-induced changes in the expression levels of programmed death-ligand 1 (PD-L1) and CD8⁺ tumor-infiltrating lymphocytes (TILs) and prognostic associations in rectal cancer.

METHODS AND MATERIALS

We performed a paired analysis using pre-CRT biopsies and the corresponding post-CRT resected tissues of 123 rectal cancer patients undergoing preoperative CRT followed by surgery between 2005 and 2012. Immunohistochemistry of PD-L1 and CD8 was analyzed for the specimens.

RESULTS

The expression levels of PD-L1 and density of CD8⁺ TILs increased after CRT (P<.001 for both). With cutoffs using each median value, sustained higher expression of PD-L1 at pre- and post-CRT (high-to-high) was associated with less increase in the density of CD8⁺ TILs (P=.020). Patients representing sustained high-to-high PD-L1 expression had poorer overall survival and disease-free interval on univariate Kaplan-Meier analysis (P=.018 and .029, respectively), with inferior disease-free interval in low-to-low density CD8⁺ TILs (P=.010). On multivariate analysis, 2 subgroups with high baseline PD-L1 expression level, the high-to-low and high-to-high alterations, showed worse overall survival (hazard ratio 8.34, 95% confidence interval 1.85-37.53 and hazard ratio 11.03, 95% confidence interval 2.33-52.29, respectively), with the highest mortality risk observed in the high-to-high group.

CONCLUSIONS

This study verified the CRT-induced immunologic shift toward increases in PD-L1 expression and density of CD8⁺ TILs in rectal cancer patients. The alteration profiles of checkpoint-related molecules identified the patients with poor prognosis, suggesting potential candidates who can benefit from combining CRT and checkpoint inhibitors.

Immune Analysis of Radium-223 in Patients With Metastatic Prostate Cancer

BACKGROUND

Radium223 (Ra223) delivers high-energy radiation to osteoblastic metastasis of prostate cancer, resulting in irreparable double-stranded DNA damage. The effects of Ra223 on CD8+ T cell subsets in patients with prostate cancer is unknown.

PATIENTS AND METHODS

Fifteen men with metastatic prostate cancer with clinical indication for Ra223 without any autoimmune or immune deficiency conditions were enrolled. Patients received a course of Ra223 50 kBq/kg. Concurrent use of prednisone ≤ 10 mg a day was allowed. Peripheral blood samples were collected before and 3 to 4 weeks after the first dose of Ra223 50 kBq/kg. Peripheral blood mononuclear cells were purified and analyzed for the phenotypic and functional characteristics of CD8⁺ T cells using flow cytometry.

RESULTS

One Ra223 treatment did not result in significant change in the overall frequencies of CD8⁺ T cells and their subsets including naive, central memory, and effect memory cells. However, the mean frequency of programmed cell death protein 1-expressing EM CD8⁺ T cells decreased after 1 Ra223 treatment from 20.6% to 14.6% (P = .020), whereas no significant change was observed in the frequencies of CD27-, CD28-, or CTLA4-expressing T cells. One Ra223 treatment was not associated with any significant change in the frequencies of CD8⁺ T cells producing IFN-γ, TNF-α, and IL-13.

CONCLUSION

One Ra223 treatment is associated with a decreased mean frequency of programmed cell death protein 1-expressing effect memory CD8⁺ T cell without affecting other immune checkpoint molecules or cytokine production. Further investigations are warranted to elucidate the immunologic and clinical significance of our observations and its long-term effects after multiple treatments.

Prognostic and predictive values of PD-L1 expression in patients with digestive system cancer: a meta-analysis

BACKGROUND

PD-L1 has been reported to be expressed in diverse human malignancies. However, the prognostic value of PD-L1 in digestive system cancers remains inconclusive. Therefore, we conducted this meta-analysis to evaluate the prognostic impact of PD-L1 expression in digestive system cancers.

MATERIALS AND METHODS

We searched the PubMed, Embase, and the Chinese National Knowledge Infrastructure for publications concerning PD-L1 expression in digestive system cancers. Correlations of PD-L1 expression level with overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) were analyzed.

RESULTS

Finally, 32 studies with 7,308 patients were included. Our results show that PD-L1 expression was significantly associated with poorer OS (hazard ratio [HR] =1.44, 95% confidence interval [CI] =1.18-1.76, P<0.001), but not DFS (HR =0.91, 95% CI =0.61-1.37, P=0.657) or RFS (HR =1.27, 95% CI =0.75-2.14, P=0.368). Moreover, in the subgroup analysis, significant associations between PD-L1 expression and OS were found in Asians (HR =1.50, 95% CI =1.19-1.89, P=0.001), gastric cancer (HR =1.43, 95% CI =1.05-1.94, P=0.021), and pancreatic carcinoma (HR =2.64, 95% CI =1.78-3.93, P<0.001).

CONCLUSION

These results suggest that the expression of PD-L1 is associated with worse OS in digestive system cancers, especially in gastric cancer and pancreatic cancer. In addition, PD-L1 may act as a new parameter for predicting poor prognosis and a promising target for anticancer therapy in digestive system cancers.

Evaluation of HLA-G, HLA-E, and PD-L1 proteins in oral osteosarcomas

OBJECTIVE

The aim of this study was to investigate the expression of human leukocyte antigens (HLAs) G and E and programmed death-ligand 1 (PD-L1) in oral osteosarcoma (OO) (n = 13). The relationship between the expression of these molecules and histologic grading and metastasis was also evaluated.

STUDY DESIGN

HLA-G, HLA-E, and PD-L1 were identified by immunohistochemistry. Samples of normal bone tissue (n = 6) were used as controls. The sections were evaluated using a semiquantitative scoring system with an immunoreactive score, where a score of 0 was considered absent, ≤2 was low, and >2 was high expression.

RESULTS

We identified high expression of HLA-G, HLA-E, and PD-L1 by malignant osteoblastic cells in 69.2% of OO cases, which was statistically higher than that in controls (P < .05). Overexpression of these proteins was identified in 8 of 11 samples of high-grade and 1 of 2 samples of low-grade OO. Additionally, 66.6% of patients with metastases (n = 4) and 71.4% of patients without metastases (n = 5) had high expression of HLA-G, HLA-E, and PD-L1 in tumor samples (P > .05).

CONCLUSION

OO had high expression of HLA-G, HLA-E, and PD-L1 irrespective of clinicopathologic parameters, including histologic grading and metastasis.