Serum Programmed Death Ligand 1 Research Articles

Correlation between iron metabolism indicators and programmed death ligand 1 expression in advanced non-small cell lung cancer.

The dysregulation of iron metabolism is closely linked to the onset and progression of lung cancer. This study aimed to explore the association between iron metabolism indicators (serum iron, transferrin, ferritin) and the expression level of programmed death factor ligand 1 in primary lesions of advanced non-small cell lung cancer. A cohort of 62 patients, including 42 men and 20 women, was recruited from October 2022 to July 2023, all diagnosed with advanced non-small cell lung cancer, confirmed through radiographic imaging and histopathological analysis. Comprehensive clinical data (such as gender, age, familial lung cancer history, smoking history, pathological classification, clinical stage, etc.) and concentrations of fasting serum iron, transferrin, and ferritin were collected. Patients were categorized into PD-L1 negative (<1% expression) and programmed death ligand 1 (PD-L1) positive (≥1% expression) groups based on PD-L1 expression levels in tumor tissues. Subsequently, the correlation between levels of serum iron, transferrin, ferritin, and PD-L1 expression in advanced non-small cell lung cancer were examined. Patients in the PD-L1 positive group exhibited lower levels of peripheral serum iron and transferrin compared to those in the PD-L1 negative group (P<0.05). For patients exhibiting positive PD-L1 expression, a negative correlation was observed between PD-L1 expression and both serum iron and transferrin levels (r = -0.465, P=0.003; r = -0.447, P=0.005), and a positive correlation was noted between PD-L1 expression and ferritin levels (r=0.393, P=0.015). We conclude that in In patients with advanced non-small cell lung cancer, serum iron and transferrin levels can serve as partial predictors of PD-L1 expression; among those positive for PD-L1, a significant association exists between indicators of iron metabolism and PD-L1 expression.

High Pretreatment Serum PD-L1 Levels Are Associated with Muscle Invasion and Shorter Survival in Upper Tract Urothelial Carcinoma.

Simple SummaryThis study aimed to assess the prognostic relevance of soluble serum PD-L1 in upper tract urothelial carcinoma (UTUC) patients who underwent surgical or systemic (chemo- or immune checkpoint inhibitor) therapy. We found that high preoperative sPD-L1 levels were correlated with higher pathological tumor stage, grade and the presence of metastasis. In addition, higher pretreatment serum PD-L1 concentrations were associated with shorter survival in both surgically and chemotherapy-treated UTUC patients. We detected a characteristic increase in serum PD-L1 levels in UTUC patients after 3 months of anti-PD-L1 therapy. Based on these results sPD-L1 is a promising prognostic biomarker in UTUC.Programmed death ligand-1 (PD-L1) is an immune checkpoint molecule and a widely used therapeutic target in urothelial cancer. Its circulating, soluble levels (sPD-L1) were recently suggested to be associated with the presence and prognosis of various malignancies but have not yet been investigated in upper tract urothelial carcinoma (UTUC). In this study, we assessed sPD-L1 levels in 97 prospectively collected serum samples from 61 UTUC patients who underwent radical nephroureterectomy (RNU), chemotherapy (CTX), or immune checkpoint inhibitor (ICI) therapy. In addition to pretreatment samples, postoperative and on-treatment sPD-L1 levels were determined in some patients by using ELISA. In the RNU group, elevated preoperative sPD-L1 was associated with a higher tumor grade (p = 0.019), stage (p < 0.001) and the presence of metastasis (p = 0.002). High sPD-L1 levels were significantly associated with worse survival in both the RNU and CTX cohorts. sPD-L1 levels were significantly elevated in postoperative samples (p = 0.011), while they remained unchanged during CTX. Interestingly, ICI treatment caused a strong, 25-fold increase in sPD-L1 (p < 0.001). Our results suggest that elevated preoperative sPD-L1 level is a predictor of higher pathological tumor stage and worse survival in UTUC, which therefore may help to optimize therapeutic decision-making. The observed characteristic sPD-L1 flare during immune checkpoint inhibitor therapy may have clinical significance.

Negative Correlation Between 18F-RGD Uptake via PET and Tumoral PD-L1 Expression in Non-Small Cell Lung Cancer.

PurposeWe investigated the correlation of 18F-AlF-NOTAPRGD2 (18F-RGD) uptake during positron emission tomography (PET) with tumoral programmed death-ligand 1 (PD-L1) expression and explored its potential in immune checkpoint inhibitor treatment.MethodsForty-two mice were subcutaneously injected with CMT-167 lung carcinoma cells. A total of 30 mice with good growth tumor and good general condition were selected. 18F-RGD PET scanning was performed on days 0, 2, 4, 6, 9, and 11 with five mice per day. Immunohistochemistry (IHC) for PD-L1 was performed on each specimen obtained from tumors. Thirty patients with advanced non-small cell lung cancer (NSCLC) were scanned using 18F-RGD PET/CT, and Milliplex multifactor detection analyzed serum PD-1/PD-L1 expression of twenty-eight of them. Thirteen of them were analyzed immunohistochemically using core needle biopsy samples obtained from primary tumors.ResultsThirty mice were scanned by 18F-RGD PET/CT and analyzed for PD-L1 expression in tumor cells by IHC finally. Maximum standard uptake value (SUVmax) and mean SUV (SUVmean) were significantly lower in relatively-higher-PD-L1-expression tumors than in relatively-low-PD-L1-expression tumors (P < 0.05). In patients, the SUVmax was significantly negatively correlated with tumoral PD-L1 expression by IHC (P=0.014). SUVmean, peak SUV (SUVpeak), and gross tumor volume (GTV) were also negatively correlated with PD-L1, but without significance (P > 0.05). SUVmax, SUVmean, SUVpeak, and GTV were negatively correlated with serum PD-1 and PD-L1, but not significantly. According to the receiver operating characteristic curve analysis, significant correlations between SUVmax and tumoral PD-L1 expression in both mice and patients were present (P < 0.05).ConclusionHigher 18F-RGD uptake is correlated with depressed PD-L1 expression in tumor cells, and SUVmax is the best parameter to display tumoral expression of PD-L1. 18F-RGD PET may be useful for reflecting the immune status of NSCLC.

Serum level of programmed death-ligand 1 in patients with gastric cancer in Mazandaran Province as a High-Risk Region in Iran

Background: Gastric cancer is one of the most common cancers in the world. Programmed death-ligand 1 (PD-L1) is the main ligand of the programmed death-1 receptor that plays a key role in apoptosis in patients with gastric cancer. Materials and Methods: In this study, forty gastric cancer patients and forty healthy controls were enrolled. Serum PD-L1 was measured by enzyme-linked immunosorbent assay. Results: The mean (interquartile range) value of expression level of PD-L1 was 70.6 (36.6–127.3) in patients and 47.7 (29.9–92.1) in controls. There were no significant differences in PD-L1 expression between the two groups and tumor characteristics, but there was a statistically significant difference between the high expression level of PD-L1 and gastric cancer development (P = 0.044, odds ratio = 2.77, 95% confidence interval = 1.12–6.86). Conclusions: PD-L1 level increases in gastric cancer patients, so it could be used as a predictor factor.

Distinct roles of programmed death ligand 1 alternative splicing isoforms in colorectal cancer.

Although anti–programmed death‐1 (PD‐1)/programmed death ligand 1 (PD‐L1) immunotherapy has achieved great success in some cancers, most colorectal cancer (CRC) patients remain unresponsive. Therefore, further clarification of the underlying mechanisms is needed to improve the therapy. In this study, we explored the distinct functions of different PD‐L1 alternative splicing isoforms in CRC. We investigated the biological functions in PD‐L1 knocked down/knockout cells, which were verified through overexpression of PD‐L1 isoforms a, b, and c. The roles of PD‐L1 isoforms in immune surveillance resistance was also analyzed. Meanwhile, we performed RNA‐seq to screen the downstream molecules regulated by PD‐L1 isoforms. Finally, we detected PD‐L1 and PD‐L1 isoforms levels in a cohort of serum samples, two cohorts of CRC tissue samples, and analyzed the correlation of PD‐L1 isoforms with PD‐1 blockade therapy response in two clinical CRC cases. The results indicated that PD‐L1 knockout inhibited proliferation, migration, and invasion, and isoform b exerted a more significant inhibitory effect on T cells than the other two isoforms. Moreover, isoform c could promote CRC progression through regulating epithelial‐mesenchymal transition. Clinical data showed that CRC patients with positive PD‐L1 expression were associated with poorer overall survival. High serum PD‐L1 level was associated with poor prognosis. The level of isoform b or c was negatively associated with prognosis, and a higher level of isoform b was associated with a good response to anti–PD‐1 therapy. In conclusion, isoform b should be considered as a biomarker for clinical responsiveness to anti–PD‐1/PD‐L1 immunotherapy; isoform c had a prometastatic role and is a new potential target for CRC therapy.

Impact of Immune Response on Outcomes in Hepatocellular Carcinoma: Association With Vascular Formation.

We investigated the prognostic value of programmed death ligand 1 (PD-L1) expression, tumor-infiltrating CD8-positive T-cell status, and their combination in hepatocellular carcinoma (HCC). Their association with PD-L1 expression and vascular formation was further explored. Using a database of 387 patients who underwent hepatic resection for HCC, immunohistochemical staining of PD-L1, CD8, and CD34 was performed. Additionally, we undertook an enzyme-linked immunosorbent assay for soluble PD-L1. Compared with patients with HCC and PD-L1-negative expression (n=311), patients with HCC and PD-L1-positive expression (n=76) showed significantly worse overall survival (OS; multivariate hazard ratio, 2.502; 95% confidence interval [CI], 1.716-3.649; P<0.0001). The presence of tumor-infiltrating CD8-positive T cells was significantly correlated with longer OS (multivariate hazard ratio, 0.383; 95% CI, 0.274-0.537; P<0.0001). Stratification based on PD-L1 expression in cancer cells and tumor-infiltrating CD8-positive T-cell status was also significantly associated with OS (log-rank, P<0.0001). HCC with PD-L1-positive expression was significantly correlated with positivity for vessels that encapsulated tumor clusters. Serum PD-L1 levels were significantly higher in the group of patients who had PD-L1-positive expression than in the group of patients who had PD-L1-negative expression (P=0.0158). PD-L1 expression in cancer cells was associated with a poor clinical outcome and vascular formation in patients with HCC. Additionally, the combination of PD-L1 expression with tumor-infiltrating CD8-positive T-cell status enabled further classification of patients based on their clinical outcome. Thus, PD-L1 expression in cancer cells and tumor-infiltrating CD8-positive T-cell status might serve as predictive tissue biomarkers.

Higher serum PD-L1 level predicts increased overall survival with lapatinib versus trastuzumab in the CCTG MA.31 phase 3 trial.

The purpose of this retrospective biomarker study of the Canadian Cancer Trials Group (CCTG) MA.31 randomized phase 3 trial (lapatinib vs trastuzumab) of HER2-positive metastatic breast cancer (MBC) was to evaluate the prognostic and predictive biomarker utility of pretreatment serum programmed death ligand 1 (PD-L1) levels. CCTG MA.31 accrued 652 HER2-positive patients; 387 had serum available (185 in the trastuzumab arm and 202 in the lapatinib arm). The Ella immunoassay platform (ProteinSimple, San Jose, California) was used to quantitate serum PD-L1 levels. Stepwise forward Cox multivariable analyses were performed for progression-free survival and overall survival (OS). In the whole trial population, continuous pretreatment serum PD-L1 levels were not associated with OS. However, within the trastuzumab arm, a higher continuous pretreatment serum PD-L1 level was significant for shorter OS (hazard ratio [HR], 3.85; P=.04), but within the lapatinib arm, pretreatment serum PD-L1 was not associated with OS (P=.37). In the whole trial, in a multivariable analysis for OS, serum PD-L1 (median cut point) remained a significant independent covariate (HR, 2.38; P=.001). There was a significant interaction between treatment arm and continuous serum PD-L1 (bootstrap method; P=.0025): at or above 214.2 pg/mL (the 89th percentile), serum PD-L1 was associated with significantly shorter OS with trastuzumab treatment versus lapatinib treatment. In the CCTG MA.31 trial, serum PD-L1 was a significant predictive factor: a higher pretreatment serum PD-L1 level was associated with shorter OS with trastuzumab treatment but with longer OS with lapatinib treatment. Immune evasion may decrease the effectiveness of trastuzumab therapy. Further evaluation of elevated serum PD-L1 in advanced breast cancer is warranted to identify patients with HER2-positive MBC who may benefit from novel immune-targeted therapies in addition to trastuzumab.

Inflammatory Serum Biomarkers in Colorectal Cancer in Kazakhstan Population.

Colorectal cancer is a type of oncopathology widespread in Kazakhstan. The genetic component, as well as the possible etiopathogenetic mechanisms, is widely studied. One of the most promising areas is the study of diagnostic and prognostic possibilities of inflammatory biomarkers in patients with different degrees of tumor differentiation. The following biomarkers were included in the study panel: stem cell factor (SCF), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF2), interleukin 6 (IL6), interleukin 8 (IL8), macrophage migration inhibitory factor (MIF), soluble Fas (SFAS), soluble Fas ligand (sFASL), transforming growth factor β (TGF), tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand (TRAIL), and programmed death ligand 1 (PD-L1). The data of our study show that most of the basic proinflammatory cytokines are involved in the systemic process and their levels do not depend on the level of tissue differentiation. Serum PD-L1 has shown itself to be a promising marker for tumor growth, which depends on the degree of differentiation.

Serum PD-1/PD-L1 Levels, Tumor Expression and PD-L1 Somatic Mutations in HER2-Positive and Triple Negative Normal-Like Feline Mammary Carcinoma Subtypes.

Tumor microenvironment has gained great relevance due to its ability to regulate distinct checkpoints mediators, orchestrating tumor progression. Serum programmed cell death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) levels were compared with healthy controls and with serum cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and tumor necrosis factor-alpha (TNF-α) levels in order to understand the role of PD-1/PD-L1 axis in cats with mammary carcinoma. PD-1 and PD-L1 expression was evaluated in tumor-infiltrating lymphocytes (TILs) and cancer cells, as the presence of somatic mutations. Results showed that serum PD-1 and PD-L1 levels were significantly higher in cats with HER2-positive (p = 0.017; p = 0.032) and triple negative (TN) normal-like mammary carcinomas (p = 0.004; p = 0.015), showing a strong positive correlation between serum CTLA-4 and TNF-α levels. In tumors, PD-L1 expression in cancer cells was significantly higher in HER2-positive samples than in TN normal-like tumors (p = 0.010), as the percentage of PD-L1-positive TILs (p = 0.037). PD-L1 gene sequencing identified two heterozygous mutations in exon 4 (A245T; V252M) and one in exon 5 (T267S). In summary, results support the use of spontaneous feline mammary carcinoma as a model for human breast cancer and suggest that the development of monoclonal antibodies may be a therapeutic strategy.

Cytokine profile during pregnancy predicts relapses during pregnancy and postpartum in multiple sclerosis

ObjectiveTo explore the serum cytokine profile associated with disease activity during pregnancy and postpartum in MS, and to assess any potential biomarkers predicting the occurrence of relapses during this period. MethodsWe included 53 MS pregnant women recruited between 2007 and 2018. Interferon-gamma, Tumor necrosis factor-alpha, interleukin-17, granulocyte/macrophage-colony stimulating factor, Activin-A, interleukin-10, and programmed-death-ligand-1 (PD-L1) were measured quarterly in serum by ELISA. ResultsSeventeen patients (32%) experienced relapses during pregnancy or puerperium and 37(68%) did not. We did not found differences in clinical characteristics or treatment status between the two groups. However, relapsing patients showed at the first trimester of pregnancy considerably lower levels of serum Activin-A (336.4 pg/dl [289.6–491.7], median [IQR] vs. 760.0 pg/dl [493.2–1108.0],p = .003), which correlated positively with serum PD-L1 (r = 0.53,p = .0005) and IL-10 (r = 0.43,p = .004) values. Activin-A levels lower than 515 pg/ml at the first trimester identified patients with high probability of relapsing during pregnancy and postpartum (OR = 13.75, CI: 2.5–76.8, p = .001). ConclusionsMS patients with no relapses during pregnancy and puerperium showed an early triggering of a tolerogenic innate immune response evidenced by high serum Activin-A concentrations during the first trimester of pregnancy. Thus, serum Activin-A can be a useful biomarker to predict clinical activity during this period.

Early transient suppression of immune checkpoint proteins T-cell immunoglobulin mucin-3 and programmed cell death-1 in peripheral blood lymphocytes after blastocyst transfer is associated with successful implantation

To compare the changing peripheral levels of immune checkpoint proteins T-cell immunoglobulin mucin-3 (Tim-3)/galectin-9 (Gal-9), and programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) over a 9-day period after blastocyst transfer between women who did and did not conceive. Prospective observational study. University teaching hospital. Fifty-one infertile women undergoing day-5 blastocyst transfer. Serial blood samples obtained on the day of embryo transfer (ET), and 3, 6, and 9 days afterward for measurement of membranous Tim-3 and PD-1 expression on various peripheral lymphocytes by flow cytometry, and serum concentrations of ligands Gal-9 and PD-L1 by ELISA. Membranous Tim-3 and PD-1 expression on lymphocytes and serum Gal-9 and PD-L1 concentrations and comparison of results between pregnant and nonpregnant women. In women who conceived, the measurements exhibited three different types of response: [1] a transient and statistically significant reduction of Tim-3+NK-like T cells, Tim-3+/PD-1+CD8+ T cells, and Tim-3+/PD-1+CD4+ T cells that returned back to baseline level 9 days after ET; [2] a reduction followed by steady increase to above baseline level on day 9 (Tim-3+CD56dimNK cells); [3] a steady increase in expression after ET to reach a level statistically significantly higher than that of the baseline by day 9 (Tim-3+CD56brightNK cells). Women who did not conceive showed no statistically significant fluctuation in any of the parameters measured across the four time pointswith exception of increased Tim-3 expression on NK cells on day 9. Successful blastocyst implantation is associated with a reduction of Tim-3 and PD-1 expression in peripheral lymphocytes on days 3 and 6 that is no longer apparent on day9.

Association of TIM-3 with BCLC Stage, Serum PD-L1 Detection, and Response to Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma.

Considering the increasing importance of immune checkpoints in tumor immunity we investigated the clinical relevance of serum T-cell immunoglobulin and mucin domain-3 (TIM-3) in patients with hepatocellular carcinoma (HCC). Serum TIM-3 levels were measured and their association with HCC stage and the detection of serum programmed death ligand-1 (PD-L1) were assessed. In patients submitted to transarterial chemoembolization (TACE), pre- and 1-week post-treatment TIM-3 levels were also evaluated. We studied 53 HCC patients with BCLC stages: 0 (5.7%), A (34%), B (32.1%), C (22.6%), and D (5.7%). The patients with advanced HCC (BCLC C) had significantly higher TIM-3 levels than patients with BCLC A (p = 0.009) and BCLC B (p = 0.019). TIM-3 levels were not associated with HCC etiology (p = 0.183). PD-L1 detection (9/53 patients) correlated with TIM-3 levels (univariate analysis, p = 0.047). In 33 patients who underwent TACE, post-treatment TIM-3 levels (231 pg/mL, 132–452) were significantly higher than pre-TACE levels (176 pg/mL, 110–379), (p = 0.036). Complete responders had higher post-TACE TIM-3 levels (534 pg/mL, 370–677) than partial responders (222 pg/mL, 131–368), (p = 0.028). Collectively, TIM-3 may have a role in anti-tumor immunity following TACE, setting a basis for combining immunotherapy and chemoembolization.

Elevated baseline serum PD-1 or PD-L1 predicts poor outcome of PD-1 inhibition therapy in metastatic melanoma

Programmed cell death protein 1 (PD-1) checkpoint inhibition has recently advanced to one of the most effective treatment strategies in melanoma. Nevertheless, a considerable proportion of patients show upfront therapy resistance and baseline predictive biomarkers of treatment outcome are scarce. In this study we quantified PD-1 and programmed death-ligand 1 (PD-L1) in baseline sera from melanoma patients in relation to therapy response and survival. Sera taken at therapy baseline from a total of 222 metastatic melanoma patients (two retrospectively selected monocentric discovery cohorts, n= 130; one prospectively collected multicentric validation cohort, n= 92) and from 38 healthy controls were analyzed for PD-1 and PD-L1 concentration by sandwich enzyme-linked immunosorbent assay. Melanoma patients showed higher serum concentrations of PD-1 (P= 0.0054) and PD-L1 (P < 0.0001) than healthy controls. Elevated serum PD-1 and PD-L1 levels at treatment baseline were associated with an impaired best overall response (BOR) to anti-PD-1 (P= 0.014, P= 0.041), but not to BRAF inhibition therapy. Baseline PD-1 and PD-L1 serum levels correlated with progression-free (PFS; P= 0.0081, P= 0.053) and overall survival (OS; P= 0.055, P=0.0062) in patients who received anti-PD-1 therapy, but not in patients treated with BRAF inhibitors. By combining both markers, we obtained a strong discrimination between favorable and poor outcome of anti-PD-1 therapy, with elevated baseline serum levels of PD-1 and/or PD-L1 associated with an impaired BOR (P= 0.037), PFS (P= 0.048), and OS (P= 0.0098). This PD-1/PD-L1 combination serum biomarker was confirmed in an independent multicenter validation set of serum samples prospectively collected at baseline of PD-1 inhibition (BOR, P= 0.019; PFS, P= 0.038; OS, P= 0.022). Multivariable Cox regression demonstrated serum PD-1/PD-L1 as an independent predictor of PFS (P= 0.010) and OS (P= 0.003) in patients treated with PD-1 inhibitors. Our findings indicate PD-1 and PD-L1 as useful serum biomarkers to predict the outcome of PD-1 inhibition therapy in melanoma patients and to select patients for PD-1-based versus BRAF-based therapy strategies.

High serum PD‐L1 level is a poor prognostic biomarker in surgically treated esophageal cancer

BackgroundProgrammed death ligand 1 (PD‐L1) inhibitor has been approved as one of the standard therapies for various cancers. Some reports have shown that serum PD‐L1 level is associated with advanced tumor stages and poor prognosis; however, corresponding pathological information in esophageal cancer patients is lacking. Therefore, we evaluated the clinicopathological and prognostic impact of serum PD‐L1 levels in surgically treated esophageal cancer.MethodsA total of 150 patients who underwent radical resection for esophageal cancer were included in the study. Preoperative serum PD‐L1 levels were analyzed using the enzyme‐linked immunosorbent assay kit. A cutoff level of 65.6 pg/mL was used to divide the patients into two groups, and univariate and multivariate analyses were conducted to compare the clinicopathological characteristics and prognoses between these two groups.ResultsAlthough significant associations between serum PD‐L1 levels and clinicopathological variables were observed, serum PD‐L1 level was significantly associated with high neutrophil counts, high CRP levels, low albumin levels, and high squamous cell carcinoma antigen levels. Furthermore, serum PD‐L1 level was associated with poor overall survival independent to TNM factors.ConclusionsHigh preoperative level of serum PD‐L1 is a prognostic factor for poor overall survival in patients with surgically treated esophageal cancer.

Clinical role of serum programmed death ligand 1 in patients with hepatocellular carcinoma: Where does it come from?

Programmed death ligand 1 (PD-L1) is a key target for the treatment of several malignancies. The present study was conducted to clarify the role of serum PD-L1 in hepatocellular carcinoma (HCC). Serum PD-L1 (sPD-L1) was examined by an enzyme-linked immunosorbent assay in 153 patients with HCC who underwent curative hepatectomy at Kumamoto University in 2011-2016. The expression of PD-L1 in tissue (tPD-L1) was investigated by immunohistochemistry. The clinical roles of the PD-L1 expression in both serum and tissue were examined. The sPD-L1 was significantly elevated in HCC patients compared to patients without any malignant or inflammatory disease (234 vs. 93pg/mL, p < 0.0001). The percentage of the tPD-L1-positive area (%tPD-L1) in the background liver was significantly higher than in the tumor (1.52% vs. 0.48%, p < 0.0001). The %tPD-L1 in the background liver but not in the tumor was significantly correlated with the sPD-L1 level (p = 0.0079). The sPD-L1, %tPD-L1 in the tumor, and %tPD-L1 in the background liver were not correlated with the overall survival after surgery. PD-L1-expressing cells in the background liver, but not in the tumor tissue, appeared to contribute to the sPD-L1 level. The sPD-L1 level may thus not indicate the tumor burden in patients with HCC.

The correlation and prognostic value of serum levels of soluble programmed death protein 1 (sPD-1) and soluble programmed death-ligand 1 (sPD-L1) in patients with hepatocellular carcinoma

BackgroundBlocking the programmed death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway in hepatocellular carcinoma (HCC) is a very promising approach in immunotherapy. However, the correlation and prognostic values of serum soluble PD-1 and PD-L1 (sPD-1/sPD-L1) have not been explored conjointly in HCC patients.MethodsThis study retrospectively included 120 HCC patients receiving radical resection. The serum levels of sPD-1/sPD-L1 and inflammatory cytokines were measured by antibody array assay. Immunohistochemistry was applied to assess both the expression of membrane-bound PD-L1, and the number of CD4+ tumor-infiltrating lymphocytes (TILs) and CD8+ TILs.ResultsThe best cut-off values of sPD-1 and sPD-L1 for predicting disease-free survival (DFS) were 33.0 µg/ml and 11.2 µg/ml, respectively. Multivariable analysis showed that sPD-L1 was a negative independent prognostic factor [DFS, Hazard Ratio (HR) 2.58, 95% CI 1.14–5.84, P = 0.023; overall survival (OS), HR 1.77, 95% CI 1.01–3.12, P = 0.048], while sPD-1 was a favorable independent prognostic factor (DFS, HR 0.32, 95% CI 0.14–0.74, P = 0.007; OS, HR 0.54, 95% CI 0.30–0.98, P = 0.044) in HCC patients. We also observed some similar associations between inflammatory cytokines (IL-10, IL-17, TNF-α) and sPD-1 or sPD-L1, as well as a close positive association between sPD-1 and sPD-L1. No significant associations of sPD-1/sPD-L1 with either intra-tumoral PD-L1 expression, or the numbers of CD4+ TILs and CD8+ TILs were determined.ConclusionsOur findings indicate that sPD-1 and sPD-L1 are independent prognostic factors with opposite prognostic roles in predicting both DFS and OS in HCC patients.

Programmed cell death protein-1 (PD-1)/programmed death-ligand-1 (PD-L1) axis in hepatocellular carcinoma: prognostic and therapeutic perspectives.

Hepatocellular carcinoma (HCC) is the most common primary neoplasia of the liver. There have been tremendous efforts in the development of therapeutic strategies in the last decades. As opposed to other cancer entities immunotherapy has just recently gained popularity in HCC. Among various immunotherapy approaches, programmed cell death protein-1 (PD-1), and its ligand programmed death receptor ligand-1 (PD-L1) axis became one of the most promising pathway of the decade. The scientific interest in PD-1/PD-L1 axis is definitely justified due to: ability to detect PD-L1 expression in patients that underwent resection for HCC with prognostic values; the role of serum PD-L1 as a tool to identify early recurrences and to monitor treatment outcome; PD-1/PDL1 is a highly targetable pathway, with possible predictive markers, and with high clinical applicability that might help us in selecting a subgroup of HCC patients who are most likely to benefit from PD-1/PD-L1 inhibitors. In this review we will first discuss the prognostic role of PD-1/PD-L1 as a bio-marker in various clinical scenarios. Afterwards we will critically analyse the recently published trials with PD-1/PD-L1 inhibitors in HCC either alone or in combination with other treatment modalities. The higher focus will be on clinical rather than preclinical studies. Nevertheless, the strengths and limits of PD-1/PD-L1 axis in both prognosis and therapy of HCC will be highlighted.

Is high serum programmed death ligand 1 level a risk factor for poor survival in patients with gastric cancer?

Background and AimAlthough the clinicopathological significance of the expression of programmed death ligand 1(PD‐L1) in various cancer tissues has been reported, serum PD‐L1 level has not been evaluated in patients with surgically treated gastric cancer. Therefore, we evaluated the clinicopathological characteristics and prognostic significance of preoperative serum PD‐L1 levels in patients with gastric cancer.Patients and MethodsSerum samples were obtained before surgery from 152 patients with gastric cancer, including 75 patients with stage I, 31 with stage II, 23 with stage III, and 23 with stage IV gastric cancer. The samples were analyzed using enzyme‐linked immunosorbent assay to detect soluble PD‐L1. Using the median serum PD‐L1 level of 50 pg/mL, patients were divided into two groups, namely high serum and low serum PD‐L1 level groups. Clinicopathological characteristics and prognosis were compared between these two groups using univariate and multivariate analysis.ResultsSerum PD‐L1 level was significantly associated with older age, positive cancer antigen 19‐9 (CA19‐9), C‐reactive protein levels, and albumin levels but not with tumor stage. Patients in the high serum PD‐L1 group showed significantly worse overall survival and recurrence‐free survival than those in the low serum PD‐L1 group (P < .05). Multivariate analysis showed that high serum PD‐L1 level was an independent risk factor for poor overall survival (P = .02).ConclusionHigh serum PD‐L1 level was a prognostic factor for reduced overall survival in patients with surgically treated gastric cancer.

Circulating PD-L1 (programmed death-ligand 1) and outcomes in a HER2-positive metastatic breast cancer cohort treated with first-line trastuzumab.

1024 Background: Recently the immune checkpoint inhibitors (ICIs) have demonstrated efficacy across a wide variety of cancers, but have been less effective in breast cancer. PD-L1 (B7-H1, CD274) is a ligand produced by many tumor cells and some immune cells, and suppresses the T cell immune response. This allows tumor cells to escape immune detection. PD-L1 is used as a companion tumor tissue IHC biomarker for patient selection for some of the FDA-approved ICIs (pembrolizumab), but not for others (nivolumab, atezolizumab). Circulating PD-L1 has been detected in multiple myeloma, renal, lung, and gastric cancer, but not in breast cancer. Here we correlated serum PD-L1 levels with outcome in a HER2-positive metastatic breast cancer cohort treated with trastuzumab. Methods: Pretreatment serum was obtained from 63 metastatic breast cancer patients before starting first-line trastuzumab-containing therapy. A novel ELLA microfluidic channel immunoassay platform (ProteinSimple, San Jose, CA) was employed to quantitate serum PD-L1. Serum PD-L1 levels were analyzed using continuous, quartile, and dichotomous (25%, median, and 75%) cutpoints. Progression-free survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Results: On a continuous basis, patients with higher serum PD-L1 had a significantly reduced PFS (p = 0.045) and overall survival OS (p = 0.004) compared to patients with lower serum PD-L1 levels. Patients with the higher quartiles of serum PD-L1 also trended to have reduced PFS (0.11) and significantly reduced OS (p = 0.015) compared to the lower quartiles of serum PD-L1. Finally, using either the 25th or 75th percentile of serum PD-L1 as dichotomous cutpoint, patients with higher serum PD-L1 had significantly reduced OS (p = 0.04). Conclusions: Higher circulating PD-L1 levels were prognostic for reduced PFS and OS in HER2-positive metastatic breast cancer patients treated with first-line trastuzumab. Circulating PD-L1 deserves further study for prognostic and predictive biomarker utility in larger trials of immune checkpoint inhibitors and other immunotherapies in breast and other cancers. AA, LK contributed equally.

Systemic immune changes associated with adjuvant interferon-α2b-therapy in stage III melanoma patients: failure at the effector phase?

Interferon-α (IFN-α) is the only approved adjuvant treatment for high-risk melanoma patients in Europe, but the impact on overall survival is low. Although it is believed that IFN-α exerts its effects through immunomodulation, data on its impact on circulating immune cells are scarce. Flow cytometry was performed on peripheral blood mononuclear cells of eight IFN-α2b-treated stage III melanoma patients and 26 untreated stage III melanoma patients as controls to enumerate myeloid and plasmacytoid dendritic cells (mDC and pDC), monocytic and polymorphonuclear myeloid-derived suppressor cells (mMDSC and pmnMDSC) and cytotoxic and regulatory T-cells (Tregs). The expression of several immunosuppressive markers [indoleamine 2,3-dioxygenase (IDO), programmed-death ligand-1 (PD-L1) and cytotoxic T-lymphocyte antigen-4 (CTLA4)] was explored. IDO activity in the blood was confirmed by ultra-performance liquid chromatography. Compared with controls, IFN-α2b treatment was associated with increased IDO expression by pDCs (P=0.021) and an increased kynurenine/tryptophan ratio in the serum (P=0.004), compatible with IDO enzyme activity. Furthermore, IFN-α2b-treated patients had a decreased mDC/DC ratio (P=0.002), decreased CD3+ lymphocytes (P=0.034) and increased circulating Treg (P<0.001) and PD-L1+cytotoxic T-cell (P=0.001) frequencies. IDO expression is upregulated in circulating pDCs of high-risk melanoma patients treated with adjuvant IFN-α2b. This is associated with tryptophan consumption in the patients' serum and higher Treg and PD-L1+cytotoxic T-cell frequencies. We hypothesize that in IFN-α2b-treated patients, IDO activity acts as a negative feedback mechanism and might limit the clinical efficacy of IFN-α2b therapy. The underlying mechanism should be explored as this could lead to more efficient immunotherapies.