Prognostic Value of Programmed Cell Death Ligand-1 Expression in Nasopharyngeal Carcinoma: A Meta-Analysis of 1,315 Patients

Predictive value of CXCL1+_FAP+ phenotype in CAFs for distant metastasis and its correlation with PD-L1 expression in locoregionally advanced nasopharyngeal carcinoma patients

OBJECTIVE

There is a lack of effective biomarkers for predicting the distant metastasis in nasopharyngeal carcinoma (NPC). We aimed to explore the expression of FAP+Cancer-associated fibroblasts (CAFs) derived CXCL1 in NPC and its predictive values for distant metastasis and correlation with PD-L1 expression.

MATERIALS AND METHODS

A total of 345 patients with locoregionally advanced NPC were retrospectively enrolled (the training cohort: the validation cohort = 160:185). Co-expression of CXCL1 and FAP and the expression of PD-L1 were detected by multi-immunofluorescence staining and immunohistochemistry, respectively. The primary end-point was distant metastasis-free survival (DMFS). The Kaplan-Meier method was used to calculate the survival. The Cox proportional hazards model was used to assess prognostic risk factors.

RESULTS

A novel CXCL1+_FAP+ phenotype in CAFs was identified in NPC and then used to divide patients into low and high risk groups. Both in the training cohort and validation cohort, patients in the high risk group had poorer DMFS, overall survival (OS), progression-free survival (PFS) and locoregional relapse-free survival (LRFS) than patients in the low risk group. Multivariate analysis revealed CXCL1+_FAP+ phenotype was an independent prognostic factor for DMFS, OS, PFS and LRFS. Further results showed patients in the high risk group had higher PD-L1 expression than those in the low risk group.

CONCLUSION

Our study showed CXCL1+_FAP+ phenotype in CAFs could effectively classified locoregionally advanced NPC patients into different risk groups for distant metastasis and might be a potential biomarker for anti-PD-1/PD-L1 immunotherapy.

PD-L1 expression as a potential predictor of immune checkpoint inhibitor efficacy and survival in patients with recurrent or metastatic nasopharyngeal cancer: a systematic review and meta-analysis of prospective trials

Background

The predictive value of programmed death-ligand 1 (PD-L1) expression in nasopharyngeal cancer (NPC) patients receiving immune checkpoint inhibitors (ICIs) remains controversial. This study aimed to evaluate the optimal threshold of PD-L1 expression in predicting the efficacy of ICIs in patients with recurrent or metastatic (R/M) NPC.

Methods

A meta-analysis was performed by retrieving relevant literature from PubMed, EMBASE, and Cochrane Library databases. Data on the pooled risk ratio (RR), mean overall survival (OS), progression-free survival (PFS), overall response rate (ORR) with 95% confidence interval, and 1%, 10%, and 25% PD-L1 expression cutoff points were obtained to examine the role of PD-L1 as a biomarker in R/M NPC patients receiving immunotherapy.

Results

In total, 1,312 patients from 14 studies were included. An improvement in PFS was observed in both patients with PD-L1 ≥ 1% (RR = 0.76, 95% CI 0.62-0.92, P = 0.005) and those with PD-L1 < 1% (RR = 0.68, 95% CI: 0.35-1.32, P = 0.26) who received first-line treatment with immunotherapy, with no significant difference between these subgroups. The pooled ORR was significantly higher in patients with PD-L1 ≥ 1% (ORR = 0.37) than in those with PD-L1 < 1% (ORR = 0.22) (P < 0.01) undergoing subsequent-line treatment. However, when we used the PD-L1 cutoff values of 10% and 25%, there was no significant difference between the positive (PD-L1 expression ≥ the cutoff value) and negative (PD-L1 expression < the cutoff value) subgroups. PD-L1 ≥ 1% also tended to be associated with better PFS and OS.

Conclusions

Our meta-analysis suggested that first-line immunotherapy could significantly improve PFS in R/M NPC patients, regardless of the PD-L1 expression levels. Positive PD-L1 expression (≥ 1%) might be a potential predictive biomarker for a better overall response to immunotherapy in R/M NPC patients in subsequent-line setting.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024495841 PROSPERO, identifier CRD42024495841.

Prognostic value of PD-L1 expression in patients with anal cancer: a meta-analysis

Background: The present meta-analysis was performed to evaluate the prognostic and clinicopathological significance of PD-L1 in anal cancer (AC). Methods: Hazard ratios (HRs) and 95% CIs regarding overall survival (OS) and progression-free survival (PFS) were calculated based on PD-L1 levels. Results: According to the combined data, PD-L1 showed no significant relationship with OS (HR = 0.76; 95% CI = 0.35-1.67; p = 0.502) or PFS (HR = 0.88; 95% CI = 0.35-2.33; p = 0.789) in patients with AC. Based on subgroup analysis, PD-L1 overexpression significantly predicted prolonged OS (HR = 0.38; 95% CI = 0.17-0.84; p = 0.017) in tumor node metastasis stages I-III and inferior PFS (HR = 2.73; 95% CI = 1.32-5.65; p = 0.007) in patients with stage I-IV AC. Conclusion: PD-L1 level assessed by immunohistochemistry did not significantly predict survival outcomes in AC cases.

Nasopharyngeal carcinoma in a non-endemic country-Validation of the new NPC staging system

BACKGROUND

Nasopharyngeal carcinoma (NPC) staging has recently been updated, with the eighth edition of the AJCC/UICC. In the last ten years, Intensity Modulated Radiotherapy (IMRT) has become a standard treatment for NPC. The authors aim to assess the benefits of the new AJCC staging system in predicting prognosis, as well as the improvement in survival outcomes in the IMRT era, in non-edemic population.

METHODS

Retrospective study selecting patients treated for NPC between January 2009 and December 2019 in a cancer treatment center in Portugal. Initial TNM staging (according to the seventh edition of the AJCC/UICC) was collected and each patient was restaged according to the new TNM staging system. Overall survival (OS) and Distant Metastasis Free Survival (DMFS) stratified by T and N classification and stage (according to the both TNM staging systems) were analyzed. Univariate and multivariate analysis was performed to evaluate which factors influence OS and DMFS. Data in this series was compared with a previous report from the same institution, before IMRT standard use.

RESULTS

113 patients were included, averaging 53.74 (±1.4) years old. With the new TNM staging, 5 patients were downstaged and 3 patients were upstaged. Over a median follow-up time of 41 months, the 5-year OS and DMFS were 77% and 79.8%, respectively. Neither the seventh nor the eighth editions of the AJCC/UICC staging system had good overall discrimination between each T classification OS and DMFS curves. Both the seventh and the eighth editions of the AJCC/UICC staging system had statistically significant overall discrimination between each N group and each stage group classification OS curves. Only N classification predicted OS in multivariate analysis. When comparing to a previous report from the same institution, OS has not improved majorly, especially in locoregionally advanced disease.

CONCLUSIONS

TNM staging still presents limitations in adequately predicting OS and DMFS.

Expression of Programmed Death Ligand-2 is associated with Prognosis in Nasopharyngeal Carcinoma Microenviroment

Background: Although immune checkpoint inhibitors have opened a new mode of treatment for solid tumors, their efficacy in nasopharyngeal carcinoma (NPC) needs to be further investigated. Inhibitors of the PD-1/PD-L1 immune checkpoint are one of the hot topics in tumor immunotherapy. Programmed death ligand-2 (PD-L2) is a less studied ligand of PD-1 and has not yet been fully explored, especially in NPC. Understanding the clinical significance of PD-L2 expression, together with immune cell infiltration, might provide clues for biomarker screening in NPC immunotherapy. This study aimed to evaluate the role of PD-L2 as a prognostic factor for NPC patients as well as its role in immune regulation. Methods: Immunohistochemistry (IHC) was performed on a tissue microarray including 557 NPC specimens using PD-L2 antibody. The immune cell markers CD4, FOXP3 and CD68 were also stained and quantified. The expression of PD-L2 exhibited different spatial patterns among NPC tumor and stromal tissues. Results: A total of 90.8% of the cases showed membranous PD-L2 expression in tumors, and 80.8% showed membranous PD-L2 expression in stromal tissue. High stromal expression of PD-L2 predicted favorable overall and disease-free survival of NPC patients and was negatively correlated with tumor size, recurrence or metastasis and clinical stage. In contrast, high tumor abundance of PD-L2 correlated with poor disease-free survival, but had no obvious correlation with clinicopathological parameters. Multivariate analysis indicated that stromal PD-L2 was an independent and favorable prognostic factor. Furthermore, we found a positive correlation between stromal PD-L2 expression and the infiltration of CD68⁺ macrophages and CD4⁺Foxp3⁺ Treg cells in NPC stromal tissues (Pearson correlation=0.181 and 0.098, respectively). Conclusions: Our results suggest that different PD-L2 expression patterns have distinct predictive values. PD-L2 expressed on stromal cells might play a role in the regulation of NPC progression, and involve in immune activation in the tissue microenvironment and have an independent good prognosis for NPC patients.

Prognostic value of PD-L1 and Siglec-15 expression in patients with nasopharyngeal carcinoma

Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) might be involved in the activation of important pathways related to tumor immune escape, along with programmed death-ligand 1 (PD-L1). Here, we aimed to investigate the correlation between the expression of Siglec-15 and PD-L1 in nasopharyngeal carcinoma (NPC) patients. We determined the expression of PD-L1 via immunohistochemical staining and that of Siglec-15 via immunofluorescence staining in 182 NPC tissue samples. A significant correlation was identified between the PD-L1 and Siglec-15 expression (P = 0.000). Moreover, Kaplan–Meier survival curves showed that PD-L1 expression was associated with improved overall survival (OS) (P = 0.025) and Siglec-15 expression was associated with improved distant failure-free survival (D-FFS) (P = 0.048). Moreover, multivariate Cox analysis showed that PD-L1 and Siglec-15 were independent predictors of OS (P = 0.020) and D-FFS (P = 0.047), respectively. The results of the log-rank test and Cox regression analyses showed that patients exhibiting no PD-L1/Siglec-15 expression had significant advantages regarding OS, compared to other groups (P = 0.037). PD-L1 and Siglec-15 may represent novel biomarkers for predicting the prognosis of NPC patients. Siglec-15 may be considered as a potential target for the development of therapeutics for NPC treatment in the future.

TGF-β1-Mediated PD-L1 Glycosylation Contributes to Immune Escape via c-Jun/STT3A Pathway in Nasopharyngeal Carcinoma

Immunotherapy targeting programmed death ligand-1/programmed cell death protein-1 (PD-L1/PD-1) has achieved great success in multiple cancers, but only a small subset of patients showed clinical responses. Recent evidences have shown that post-translational modification of PD-L1 protein could regulate its protein stability and interaction with cognate receptor PD-1, thereby affecting anticancer immunotherapy in several solid tumors. However, the molecular mechanisms underlying how PD-1/PD-L1 expression is regulated still remain unclear in nasopharyngeal carcinoma (NPC). Here, we found N-glycosylation of PD-L1 in NPC cells and tissues. Mechanistically, we showed that STT3A transferred N-linked glycans to PD-L1, and TGF-β1 could positively regulate STT3A expression through activating c-Jun to bind to STT3A promoter. Functional assays showed that inhibition of TGF-β1 resulted in a decrease of glycosylated PD-L1 and enhanced cytotoxic T-cell function against NPC cells. Analysis of clinical specimens revealed that the expression of STT3A was positively correlated with TGF-β1 and c-Jun, and high STT3A expression was positively correlated with a more advanced clinical stage. Altogether, TGF-β1 activated c-Jun/STT3A signaling pathway to promote N-glycosylation of PD-L1, thus further facilitating immune evasion and reducing the efficacy of cancer immunotherapy. As such, all these data suggested that targeting TGF-β1 pathway might be a promising approach to enhance immune checkpoint blockade, and simultaneous blockade of PD-L1 and TGF-β1 pathways might elicit potent and superior antitumor activity relative to monotherapies.

Combined Association of Tumoral PD-L1 Expression and Pretreatment Presence of Epstein-Barr Virus DNA With Risk Stratification and Prognosis of Patients With Nasopharyngeal Carcinoma

Background

Little is known about whether the combination of tumor programmed death-ligand 1 (PD-L1) expression and pretreatment EBV DNA status can help stratify nasopharyngeal carcinoma (NPC) patients by risk of metastasis or predict prognosis.

Methods

PD-L1 expression was assessed using immunohistochemical staining of 78 non-keratinizing NPC patients with clinical data. Survival outcomes and independent prognostic factors were identified.

Results

Seventy-eight patients were included, high PD-L1 expression was observed in 25 of 43 patients (58%) with metastasis, while it was observed only in 7 of 35 patients (20%) without metastasis. Multivariate analyses showed that progression-free survival (PFS) was independently predicted by tumoral PD-L1 expression and pretreatment EBV DNA status. When combining, 93.75% patients with high PD-L1 and EBV infection developed distant metastasis, and those patients were associated with worse PFS.

Conclusions

Both PD-L1 expression and pretreatment EBV DNA are closely related to metastasis and prognosis of NPC patients. Their combination can facilitate risk stratification and prognosis prediction, which may improve disease treatment and management.

Combined Identification of Novel Markers for Diagnosis and Prognostic of Classic Hodgkin Lymphoma

BACKGROUND

An effective diagnostic and prognostic marker based on the gene expression profile of classic Hodgkin lymphoma (cHL) has not yet been developed. The aim of the present study was to investigate potential markers for the diagnosis and prediction of cHL prognosis.

METHODS

The gene expression profiles with all available clinical features were downloaded from the Gene Expression Omnibus (GEO) database. Then, multiple machine learning algorithms were applied to develop and validate a diagnostic signature by comparing cHL with normal control. In addition, we identified prognostic genes and built a prognostic model with them to predict the prognosis for 130 patients with cHL which were treated with first-line treatment (ABVD chemotherapy or an ABVD-like regimen).

RESULTS

A diagnostic prediction signature was constructed and showed high specificity and sensitivity (training cohort: AUC=0.981,95% CI 0.933-0.998, P<0.001, validation cohort: AUC=0.955,95% CI 0.895-0.986, P<0.001). Additionally, nine prognostic genes (LAMP1, STAT1, MMP9, C1QB, ICAM1, CD274, CCL19, HCK and LILRB2) were screened and a prognostic prediction model was constructed with them, which had been confirmed effectively predicting prognosis (P<0.001). Furthermore, the results of the immune infiltration assessment indicated that the high scale of the fraction of CD8 + T cells, M1 macrophages, resting mast cells associated with an adverse outcome in cHL, and naive B cells related to prolonged survival. In addition, a nomogram that combined the prognostic prediction model and clinical characteristics is also suggested to have a good predictive value for the prognosis of patients.

CONCLUSION

The new markers found in this study may be helpful for the diagnosis and prediction of the prognosis of cHL.

The clinical prognostic value of PD-L1 after concurrent chemoradiotherapy in Chinese nasopharyngeal carcinoma patients

Background

Although immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of nasopharyngeal carcinoma (NPC), it is still the second- or third-line treatment after the failure of radiotherapy or chemotherapy. In this study, we aimed to investigate the impact of concurrent chemoradiotherapy (CCRT) on programmed death-ligand 1 (PD-L1) protein expression in NPC patients.

Methods

We enrolled 24 NPC patients treated with intensity-modulated radiation therapy (IMRT) combined with cisplatin CCRT. PD-L1 expression was evaluated by immunohistochemistry, and next-generation sequencing and annotation were performed to determine the genetic alteration after CCRT.

Results

Our results showed that patients with a high expression of PD-L1 were more inclined to a complete response (CR) to chemoradiotherapy, as opposed to a partial response (PR) (P<0.05). Moreover, the mean values of the tumor mutation burden (TMB) and the tumor neoantigen burden (TNB) in the PD-L1 positive group were significantly lower than that of the PD-L1 negative group in our cohort.

Conclusions

We confirmed that the TMB and TNB may be potential clinical indicators in NPC treatment, and PD-L1 expression may be a clinical biomarker in NPC chemoradiotherapy. Finally, through next-generation sequencing and annotation, we found that the most frequent driver gene mutations in NPC were TET2, TP53, and MAPK.

LAPTM4B promotes the progression of nasopharyngeal cancer

Lysosomal protein transmembrane 4 beta (LAPTM4B) is a protein that contains four transmembrane domains. The impact of LAPTM4B on the malignancy of nasopharyngeal carcinoma (NPC) remains unclear. In the present study, we aimed to investigate the role of LAPTM4B in NPC. NPC tissue samples were used to evaluate the expression of LAPTM4B and its relationship with patient prognosis. Furthermore, we inhibited the expression of LAPTM4B in NPC cell lines and examined the effects of LAPTM4B on NPC cell proliferation, migration, and invasion. We found that LAPTM4B protein was mainly localized in the cytoplasm and intracellular membranes of NPC cells. LAPTM4B protein was upregulated in NPC tissues and cell lines. High LAPTM4B expression was closely related to pathological subtypes and disease stages in NPC patients. NPC patients with high LAPTM4B expression had a worse prognosis. LAPTM4B knockdown inhibited the proliferation, migration, and invasion ability of NPC cells. LAPTM4B plays a cancer-promoting role in the progression of NPC and may be a potential target for NPC therapy.

Co-expression of CMTM6 and PD-L1: a novel prognostic indicator of gastric cancer

BACKGROUND

CKLF Like MARVEL Transmembrane Domain Containing 6 (CMTM6) is involved in the epigenetic regulation of genes and tumorigenesis. Programmed cell death ligand 1 (PD-L1) is closely related to the prognosis of some human cancers. CMTM6 is a key regulator of PD-L1 in many cancers. The purpose of this study was to investigate the expressions of these proteins in gastric cancer and the correlations with clinicopathological features and survival.

METHODS

The expression levels of CMTM6 and PD-L1 were examined in 185 gastric cancer specimens using immunohistochemistry, quantitative real-time PCR and Western blot. Immunofluorescence was used to examine the localizations of CMTM6 and PD-L1. Chi-square test was used to analyze the relationship between CMTM6 and PD-L1 expressions and clinicopathological characteristics. Kaplan-Meier method and log-rank test were used to analyze the survival data of patients.

RESULTS

The positive expression rates of CMTM6 and PD-L1 in gastric cancers were 78.38% (145/185) and 75.68% (140/185), respectively. CMTM6 and PD-L1 were both mainly expressed in the cell membrane and nucleus of gastric cancer tumor cells. High expression of CMTM6 and PD-L1 was correlated with Borrmann type (P < 0.001), N stage (P = 0.002), peritoneal metastasis (P = 0.007) and TNM stage (P = 0.038). CMTM6 and PD-L1 expression in gastric cancer tissues showed a positive correlation (Pearson's coefficient test, r = 0.260; P < 0.001). CMTM6 may positively regulate PD-L1 expression. High expression of CMTM6 was correlated with poor prognosis of gastric cancer patients (HR = 1.668; 95% CI = 1.032-2.695; P = 0.037). High expression of both CMTM6 and PD-L1 may be an independent factor for overall survival (HR = 1.554; 95% CI = 1.011-2.389; P = 0.044).

CONCLUSION

The combined detection of CMTM6 and PD-L1 may be used as an indicator for judging the prognosis of gastric cancer patients.

The clinicopathological significance and prognostic value of programmed death-ligand 1 in prostate cancer: a meta-analysis of 3133 patients

Background: Programmed death-ligand 1 (PD-L1) is considered an adverse factor predicting poor prognosis in various cancers, but the significance of PD-L1 expression for the prognosis of prostate cancer (PCa) is still unclear. We aimed to investigate the clinicopathological significance and prognostic value of PD-L1 expression in PCa.

Methods: Studies were retrieved from PubMed, Web of Science, Cochrane Library and Embase before March 23, 2020. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were obtained to assess the results. Begg’s test was applied to evaluate publication bias.

Results: Fourteen studies involving 3133 cases were analyzed. The pooled data showed that both PD-L1 protein expression and PD-L1 DNA methylation (mPD-L1) were negatively associated with biochemical recurrence-free survival, with HRs of 1.67 (95% CI = 1.38-2.06, p < 0.001) and 2.23 (95% CI = 1.51-3.29, p < 0.001), respectively. In addition, PD-L1 overexpression was significantly related to advanced tumor stage (OR = 1.40, 95% CI= 1.13-1.75, p = 0.003), positive surgical margin (OR = 1.36, 95% CI = 1.03-1.78, p = 0.028), higher Gleason score (OR = 1.81, 95% CI = 1.35-2.42, p < 0.001) and androgen receptor positivity (OR = 2.20, 95% CI = 1.61-3.01, p < 0.001), while no significant correlation with age (p = 0.122), preoperative PSA (p = 0.796) or nodal status (p = 0.113) was observed.

Conclusions: The study revealed that high expression of PD-L1 was related to unfavorable prognosis and advanced clinicopathological factors in PCa patients.

PD-L1 Expression is Highly Associated with Tumor-Associated Macrophage Infiltration in Nasopharyngeal Carcinoma

Purpose

Tumour-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment and provide a barrier against the cytotoxic effector functions of T cells and natural killer (NK) cells. Recently, TAMs have become increasingly recognised as an attractive target in combination therapy with PD-1/PD-L1 immuno-checkpoint blockades (ICBs). However, the relationship between PD-L1 expression and TAMs remains unknown in nasopharyngeal carcinoma (NPC).

Patients and Methods

A total of 212 NPC patients from Nanfang hospital were collected in this study. We evaluated the expression of PD-L1 in tumor cells, CD68 (pan-macrophages), and CD163 (M2-like macrophage) in NPC tissues using immunohistochemical (IHC) staining.

Results

The positivity of PD-L1 on tumor cells was 61.3% (130/212). The infiltration densities of CD68+ cells and CD163+ cells in PD-L1-positive NPC tissues were significantly higher than those in PD-L1-negative NPC tissues (P=0.0012 for CD68; P<0.0001 for CD163). Logistic regression analysis showed that high densities of CD68+ macrophages and CD163+ TAMs were significantly associated with increased PD-L1 expression. Subgroup analyses demonstrated that a positive PD-L1 expression on tumor cells in combination with lower CD163+ TAMs density was significantly associated with favorable prognosis, whereas negative PD-L1 expression on tumor cells with higher CD163+ TAMs density was associated with worse prognosis.

Conclusion

The PD-L1 expression in tumor cells was positively correlated with TAMs density in tumor microenvironment of NPC, suggesting TAMs as a new target for combination therapy to improve the response rate of ICBs in NPC treatment.

Prognostic and clinicopathological value of Ki-67 expression in patients with nasopharyngeal carcinoma: a meta-analysis

Background

This meta-analysis aimed to identify the prognostic role of Ki-67 in patients with nasopharyngeal carcinoma (NPC).

Methods

Relevant studies were retrieved in the PubMed, Embase, Web of Science, and Cochrane Library databases up to November 2019. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to estimate the association between Ki-67 expression and survival outcomes. Combined odds ratios (ORs) and 95% CIs were measured as effect size on the association between Ki-67 expression and clinical factors.

Results

A total of eight studies involving 936 patients with NPC were included in this meta-analysis. The pooled HR indicated that Ki-67 expression was significantly associated with poor overall survival (HR = 2.86, 95% CI = 1.91-4.27, p < 0.001), progression-free survival (HR = 1.78, 95% CI = 1.15-2.74, p = 0.009), and distant metastasis-free survival (HR = 1.65, 95% CI = 1.15-2.36, p = 0.007). However, there was no significant correlation between Ki-67 expression and local recurrence-free survival (HR = 1.07, 95% CI = 0.54-2.14, p = 0.843). Ki-67 overexpression was associated with higher T stage (OR = 1.48, 95% CI = 1.00-2.20, p = 0.052), and the relationship between Ki-67 expression and advanced stage was nearly significant (OR = 2.25, 95% CI = 0.99-5.14, p = 0.054). However, high Ki-67 expression was not significantly correlated with sex, age, N stage, or histological type.

Conclusion

This meta-analysis demonstrated that Ki-67 overexpression was a significant marker for poor prognosis in patients with NPC. Ki-67 should be recommended as a useful index for prognostication in patients with NPC.

Prognostic and clinicopathological utility of programmed death-ligand 1 in malignant pleural mesothelioma: A meta-analysis

OBJECTIVE

Programmed death ligand 1 (PD-L1) has been reported to be connected to prognosis in individuals with malignant pleural mesothelioma (MPM), although there is no consensus based on data from previous studies. Accordingly, this quantitative meta-analysis investigated prognostic and clinicopathological utility of PD-L1 in patients with MPM.

METHODS

A comprehensive search of the PubMed, Web of Science, Embase, and Cochrane Library databases for articles published up to October 4, 2019 was performed. Studies using immunohistochemical techniques to detect/quantify the expression of PD-L1 in MPM tissue were enrolled in the analysis. The combined hazard ratio (HR) and corresponding 95% confidence interval (CI) was applied to assess the association between PD-L1 expression and overall survival (OS).

RESULTS

A total of 11 studies comprising 1606 patients was included in the present meta-analysis. For OS, pooled data revealed an HR of 1.50 (95% CI 1.32-1.70; p < 0.001), suggesting that patients with PD-L1 overexpression experience inferior OS. Subgroup analysis revealed that elevated PD-L1 remained a significant prognostic indicator for worse OS, irrespective of sample size, cut-off value, ethnicity, and Newcastle-Ottawa Scale score. Moreover, PD-L1 overexpression was associated with non-epithelioid histology (odds ratio 4.30 [95% CI 1.89-9.74]; p < 0.001).

CONCLUSIONS

Results of this meta-analysis show that elevated expression of PD-L1 could be a factor predicting poorer survival in patients with MPM.

A pooled analysis of the prognostic value of PD-L1 in melanoma: evidence from 1062 patients

Background

Programmed death-ligand 1 (PD-L1) was the first identified ligand of programmed death-1 (PD-1). PD-1/PD-L1 interactions inhibit T cell-mediated immune responses, limit cytokine production, and promote tumor immune escape. Recently, many studies have investigated the prognostic value of PD-L1 expression in patients with melanoma. However, the results of these analyses remain a subject of debate. We have therefore carried out a meta-analysis to identify the prognostic role of PD-L1 in melanoma.

Methods

A thorough medical literature search was performed in the databases PubMed, Web of Science, and Embase until October 2019. The pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated to evaluate the correlation between PD-L1 overexpression and prognosis. Publication bias was evaluated using Begg’s test and Egger’s test.

Results

Thirteen articles with 1062 enrolled patients were included in this meta-analysis. High PD-L1 expression did not correlate with overall survival (OS) (HR = 0.93, 95% CI 0.57–1.52, P = 0.781) or progression-free survival (PFS) (HR = 0.82, 95% CI 0.43–1.54, P = 0.535). However, PD-L1 overexpression correlated with the absence of lymph node (LN) metastasis (OR = 0.46, 95% CI 0.22–0.95, P = 0.036). Further, there was no significant relationship between PD-L1 expression and sex (OR = 1.29, 95% CI 0.90–1.84, P = 0.159), age (OR = 0.90, 95% CI 0.51–1.57, P = 0.708), or Eastern Cooperative Oncology Group Performance Status (OR = 0.55, 95% CI 0.06–4.83, P = 0.592).

Conclusions

This meta-analysis suggested that PD-L1 expression did not predict an inferior prognosis in patients with melanoma. However, high PD-L1 expression was associated with absence of LN metastasis in such patients.