Elevated serum soluble programmed cell death ligand 1 concentration as a potential marker for poor prognosis in small cell lung cancer patients with chemotherapy

Soluble immune checkpoints: implications for cancer prognosis and response to immune checkpoint therapy and conventional therapies

Longitudinal sampling of tumor tissue from patients with solid cancers, aside from melanoma and a few other cases, is often unfeasible, and thus may not capture the plasticity of interactions between the tumor and immune system under selective pressure of a given therapy. Peripheral blood analyses provide salient information about the human peripheral immunome while offering technical and practical advantages over traditional tumor biopsies, and should be utilized where possible alongside interrogation of the tumor. Some common blood-based biomarkers used to study the immune response include immune cell subsets, circulating tumor DNA, and protein analytes such as cytokines. With the recent explosion of immune checkpoint inhibitors (ICI) as a modality of treatment in multiple cancer types, soluble immune checkpoints have become a relevant area of investigation for peripheral immune-based biomarkers. However, the exact functions of soluble immune checkpoints and their roles in cancer for the most part remain unclear. This review discusses current literature on the production, function, and expression of nine soluble immune checkpoints - sPD-L1, sPD-1, sCTLA4, sCD80, sTIM3, sLAG3, sB7-H3, sBTLA, and sHVEM - in patients with solid tumors, and explores their role as biomarkers of response to ICI as well as to conventional therapies (chemotherapy, radiotherapy, targeted therapy, and surgery) in cancer patients.

Small-Cell Lung Cancer: Is Liquid Biopsy a New Tool Able to Predict the Efficacy of Immunotherapy?

Small-cell lung cancer (SCLC) cases represent approximately 15% of all lung cancer cases, remaining a recalcitrant malignancy with poor survival and few treatment options. In the last few years, the addition of immunotherapy to chemotherapy improved clinical outcomes compared to chemotherapy alone, resulting in the current standard of care for SCLC. However, the advantage of immunotherapy only applies to a few SCLC patients, and predictive biomarkers selection are lacking for SCLC. In particular, due to some features of SCLC, such as high heterogeneity, elevated cell plasticity, and low-quality tissue samples, SCLC biopsies cannot be used as biomarkers. Therefore, the characterization of the tumor and, subsequently, the selection of an appropriate therapeutic combination may benefit greatly from liquid biopsy. Soluble factors, circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and extracellular vesicles (EVs) are now useful tools in the characterization of SCLC. This review summarizes the most recent data on biomarkers detectable with liquid biopsy, emphasizing their role in supporting tumor detection and their potential role in SCLC treatment choice.

Prognostic Role of Soluble Programmed Death Ligand 1 in Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

The objective of this study was to explore whether soluble programmed death ligand 1 (sPD-L1) is a potential prognostic biomarker in patients with non-small cell lung cancer (NSCLC).

METHODS

A comprehensive search of electronic databases was carried out. Original studies with inclusion of sPD-L1, progression-free survival, and overall survival in NSCLC were eligible. The primary endpoints were overall survival and progression-free survival. Hazard ratios (HRs) and 95% confidence intervals (CIs) were applied for data analysis.

RESULTS

Eight studies involving 710 patients with NSCLC were included in the analysis. A pooled data analysis revealed that high levels of sPD-L1 were correlated with poorer overall survival (HR = 2.34; 95% CI = 1.82-3.00; P < 0.001) and progression-free survival (HR = 2.35; 95% CI = 1.62-3.40, P < 0.001). A subgroup analysis revealed that high levels of sPD-L1 were correlated with poor overall survival in patients treated with immunotherapy (HR = 2.40; 95% CI = 1.79-3.22; P < 0.001).

CONCLUSION

This pooled analysis of published data suggests that sPD-L1 may serve as a readily available biomarker for survival in NSCLC patients treated with ICI based treatment. Prospective studies with well-designed standard assessment methods should be conducted to validate the prognostic role of sPD-L1 in NSCLC.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021283177.

Soluble PD-L1 as a predictive biomarker in lung cancer: a systematic review and meta-analysis

Background: We performed a meta-analysis to evaluate the association between soluble PD-L1 (sPD-L1) and survival outcomes and treatment response in lung cancer. Methods & methods: Eligible studies were obtained by searching PubMed, EMBASE and Web of Science. Pooled effect estimates were calculated for overall survival (OS), progression-free survival (PFS) and objective response rate (ORR). Results: Twelve eligible studies with 1188 lung cancer patients were included. High sPD-L1 was significantly associated with worse OS (hazard ratio [HR] = 2.20; 95% CI: 1.59-3.05; p < 0.001) and PFS (HR = 2.42; 95% CI: 1.72-3.42; p < 0.001) in patients treated with immune checkpoint inhibitors (ICIs). Meanwhile, high sPD-L1 predicted worse OS (HR = 1.60; 95% CI: 1.31-1.96; p < 0.001) and lower ORR (odds ratio = 0.52; 95% CI: 0.35-0.80; p = 0.002) in patients treated with non-ICI therapies. Conclusion: sPD-L1 is a potential predictive biomarker of lung cancer.

The Prognostic Value of Circulating Soluble Programmed Death Ligand-1 in Cancers: A Meta-Analysis

Background

Studies on the prognostic value of the soluble programmed death ligand 1 (sPD-L1) in cancer patients have not yielded consistent results.

Objective

This meta-analysis was performed to assess the association between sPD-L1 and the prognosis of cancer patients.

Methods

Published articles in Pubmed, EMBASE, and Cochrane clinical trial databases were searched from the inception to September 2020. Overall survival (OS), progression-free survival (PFS), recurrence-free survival (RFS), and disease-free survival (DFS) data were evaluated using a hazard ratio (HR) at 95% confidence interval (95% CI).

Results

A total 31 studies involving 17 tumors and 3,780 patients were included. The overexpression of sPD-L1 was associated with shorter OS (HR 1.85, 95% CI 1.59–2.15, I² = 33%). High sPD-L1 had worse PFS (HR 2.40, 95% CI 1.55–3.72, I² = 83%), and worse DFS (HR 2.92, 95% CI 2.02–4.29, I² = 40%), without significant statistical difference in RFS (HR 2.08, 95% CI 0.99–4.40, I² = 0%).

Conclusions

High sPD-L1 levels were associated with worse survival prognosis in cancer patients. The sPD-L1 may be a potential prognostic, non-invasive, and dynamic monitoring biomarker for cancers in the future.

The benefits of etoposide capsules as maintenance therapy for patients with extensive-stage small cell lung cancer: a prospective two-stage, two-center study

Background

Due to the high incidence and mortality of lung cancer, and etoposide is the standard first-line chemotherapy for small cell lung cancer, to evaluate the efficacy and safety of etoposide capsules at different doses as maintenance therapy for patients with extensive-stage small cell lung cancer (ES-SCLC) who show a response to etoposide plus platinum.

Methods

The study was divided into two stages: stage I, a single-center, one-arm prospective study, and stage II, a multicenter, controlled non-randomized prospective study (patients were chosen from ClinicalTrials.gov Identifier: NCT02179528). All patients received six cycles of etoposide plus platinum. Patients who were evaluated as complete remission (CR) or partial remission (PR) entered the maintenance treatment (MT) (etoposide capsule, once a day for 20 days, every 28 days as a cycle, until disease progression). In stage I, the dose of etoposide was 25 mg; in stage II, patients were non-randomized into etoposide capsule (25 mg/50 mg) and observation groups. In this study, the primary endpoints were progression-free survival (PFS) and safety; the secondary endpoint was overall survival (OS). Toxicity was graded according to the Common Terminology Criteria for Adverse Events v3.0.

Results

Ninety-two patients were enrolled. In stage I, the median PFS was 6.700 months (95% CI: 6.408–6.992). In stage II, the median PFS of the MT group was better than that in the NMT group (8.930 vs. 5.900 months, P=0.002). In the pooled analysis, the overall median PFS of the MT group was better than that of the NMT group (7.870 vs. 5.900 months, P=0.003). However, there was no significant difference in OS between the groups (15.030 vs. 14.330 months, P=0.813). Multivariate Cox regression analysis showed that maintenance therapy was an independent protective factor for PFS in patients with ES-SCLC.

Conclusions

Etoposide capsules as maintenance therapy significantly prolonged the PFS of patients with ES-SCLC who responded to etoposide plus platinum, with acceptable tolerability.

Prognostic Value of Soluble Programmed Cell Death Ligand-1 (sPD-L1) in Various Cancers: A Meta-analysis

BACKGROUND

The prognostic value of soluble programmed cell death ligand-1 (sPD-L1) in patients with cancer has been inconsistent across previous studies.

OBJECTIVE

This meta-analysis aimed to investigate the prognostic significance of sPD-L1 in human tumors.

METHODS

A comprehensive search of PubMed, Web of Science, Embase, and Cochrane databases from inception to January 6, 2020 was conducted. Studies of sPD-L1 measured by enzyme-linked immunosorbent assay (ELISA) that had available hazard ratios (HRs) for survival outcomes based on high or low sPD-L1 levels were included. The primary endpoint was long-term survival, namely, overall survival (OS), and the second endpoint was short-term survival, including progression-free survival (PFS), disease-free survival (DFS), recurrence-free survival (RFS), and cancer-specific survival (CSS).

RESULTS

A total of 21 studies, with 2413 patients, were included in this meta-analysis. Elevated sPD-L1 was associated with worse OS [HR = 2.46, 95% confidence interval (CI) 1.74-3.49, P < 0.001]. Moreover, high sPD-L1 was predictive of worse PFS/DFS/RFS/CSS (HR = 2.22, 95% CI 1.47-3.35, P < 0.001). High sPD-L1 was consistently correlated with poor OS and PFS/DFS/RFS/CSS irrespective of study design, sample, and cut-off value of sPD-L1. However, there was non-significant correlation between sPD-L1 and sex, age, clinical stage, Eastern Cooperative Oncology Group Performance Status, tumor differentiation, or serum lactate dehydrogenase.

CONCLUSIONS

This meta-analysis showed that sPD-L1 was correlated with poor prognosis in human tumors. In addition, sPD-L1 could be used as a predictive factor of inferior outcomes during multiple malignancy treatments.

Association between clinicopathological features and prognosis significance of PD-L1 expression in small cell lung cancer patients: a systemic review and meta-analysis

BACKGROUND

Programmed death ligand-1 (PD-L1) has been identified as an established biomarker for predicting response to immunotherapy in a variety types of cancer. However, the clinicopathological and prognostic significance of this protein in small cell lung cancer (SCLC) patients remains controversial.

METHODS

Eligible studies extracted from the databases of PubMed, MEDLINE, Embase, and CNKI databases were evaluated. Statistical analysis was performed using STATA 11.2 software.

RESULTS

A total of 483 PD-L1+ cases and 570 controls from 11 publications were extracted. Either overall analysis or subcategory analysis showed that no significant association between higher PD-L1 expression and gender (n=8, OR 1.08, 95% CI: 0.73-1.61, P=0.704, I²=0.0%), tumor stage (n=5, OR 0.71, 95% CI: 0.20-2.56, P=0.599, I²=86.5%), smoking status (n=4, OR 0.85, 95% CI: 0.41-1.73, P=0.646, I²=0.0%), and the level of serum lactate dehydrogenase (LDH) (n=4, OR 0.76, 95% CI: 0.48-1.20, P=0.241, I²= 21.6%). PD-L1 expression had no positive correlation with overall survival (OS) (n=11, HR 0.97, 95% CI: 0.61-1.56, P=0.904, I²= 83.2%) in overall analysis. However, the stratified analysis showed that increased expression of PD-L1 predicted a significantly better OS in monoclonal antibody (mAb) subgroup and Food and Drug Administration (FDA) approved antibody clone specification (22C3/28-8/SP142/SP263) subgroup without significant heterogeneity.

CONCLUSIONS

PD-L1 is not an important predictor of most clinicopathological features of SCLC patients, but it can predict an improved survival when using mAb or FDA approved clone specifications in IHC assays.

Prognostic role of pretreatment neutrophil-to-lymphocyte ratio in non-small cell lung cancer patients treated with systemic therapy: a meta-analysis

Background

Neutrophil-to-lymphocyte ratio (NLR) is related to prognosis in non-small cell lung cancer (NSCLC). However, no consensus on the relationship of pretreatment NLR and survival outcomes of systemic therapy in NSCLC exists. This meta-analysis investigated the prognostic role of pretreatment NLR during systemic therapy for NSCLC, including chemotherapy, immunotherapy and targeted therapy.

Methods

PubMed, Web of Science and Cochrane Library databases were systematically searched up to April 09, 2019. Hazard ratios (HRs) with their 95% confidence intervals (CIs) were pooled to investigate the association of pretreatment NLR with progression-free survival (PFS) and overall survival (OS).

Results

In total, 27 articles with 4,298 participants were selected. The pooled results showed that elevated pretreatment NLR was associated with inferior PFS (HR, 1.45, 95% CI, 1.28-1.66) and OS (HR, 1.63, 95% CI, 1.43-1.84) during systemic therapy. Subgroup analyses according to the treatment strategy suggested that higher pretreatment NLR was significantly associated with shorter survival in all therapies, including chemotherapy (PFS HR, 1.74, 95% CI, 1.39-2.17; OS HR, 1.73, 95% CI, 1.26-2.36), immunotherapy (PFS HR, 1.53, 95% CI, 1.27-1.84; OS HR, 2.50, 95% CI, 1.60-3.89) and targeted therapy (PFS HR, 1.53, 95% CI, 1.04-2.25; OS HR, 1.92, 95% CI, 1.14-3.24).

Conclusions

Pretreatment NLR is a promising prognostic indicator for NSCLC patients receiving systemic therapy, including chemotherapy, immunotherapy and targeted therapy.