PD-L1 expression as biomarker of efficacy of PD-1/PD-L1 checkpoint inhibitors in metastatic triple negative breast cancer: A systematic review and meta-analysis

Immune Checkpoint Inhibitors and Immunosuppressive Tumor Microenvironment: Current Challenges and Strategies to Overcome Resistance

Immune checkpoint inhibitors (ICIs) are shown to improve cancer treatment effectiveness by boosting the immune system of the patient. Nevertheless, the unique and highly suppressive TME poses a significant challenge, causing heterogeneity of response or resistance in a considerable number of patients. This review focuses on the evasive attributes of the TME. Immune evasion mechanism in TME include immunosuppressive cells, cytokine and chemokine signaling, metabolic alterations and overexpression of immune checkpoint molecules such as PD-1, CTLA-4, LAG-3, TIM-3, TIGIT, BTLA and their interactions within the TME. In addition, this review focuses on the overcoming resistance by targeting immunosuppressive cells, normalizing tumor blood vessels, blocking two or three checkpoints simultaneously, combining vaccines, oncolytic viruses and metabolic inhibitors with ICIs or other therapies. This review also focuses on the necessity of finding predictive markers for the stratification of patients and to check response of ICIs treatment. It remains to be made certain by new research and intelligent innovations how these discoveries of the TME and its interplay facilitate ICI treatment and change the face of cancer treatment.

Positivity Rate of PD-L1 Expression and Its Clinical Significance in Vulvar Cancer: A Systematic Review and Meta-Analysis

The prevalence and prognostic value of programmed death ligand 1 (PD-L1) expression, as a potential biomarker in vulvar squamous cell carcinomas (VSCCs), remain underexplored. We searched the PubMed, Scopus, Embase, and Cochrane Library databases until July 2024 for articles examining PD-L1 expression in VSCCs. Random-effects meta-analyses summarized PD-L1 expression overall and in subgroups by immunohistochemistry antibody type, positivity cutoff, tumor stage, and HPV positivity. Additionally, random-effects meta-analyses summarized the association between PD-L1 positivity and cancer prognosis. We included 26 studies comprising 1912 VSCC cases. The summary PD-L1 positivity rate in tumor cells was 59.9% (95% confidence interval [CI]: 47.7-71.4%; I2 = 96%, n = 26), influenced by the different cutoff thresholds utilized to define PD-L1 positivity. Compared to tumor cells, positivity rates were higher in intratumoral immune cells (75.6%; 95%CI: 52.9-92.5; I2 = 95.4%, n = 6) and peritumoral cells (78.9%; 95%CI: 54.4-95.5%; I2 = 91%, n = 3) but with overlapping 95%CIs. No heterogeneity was observed in the rates by tumor stage or HPV status. Positive PD-L1 expression was associated with worse overall (hazard ratio [HR] = 1.43; 95%CI: 1.06-1.93; I2 = 28.9%, n = 7) and progression-free survival (HR = 1.57; 95%CI: 1.07-2.3; I2 = 38.3%, n = 5). The PD-L1 expression rate in VSCC tumor cells varied across studies, was influenced by differences in immunohistochemical evaluation, and was identified as an unfavorable prognostic factor. Large, prospective, multicenter studies with standardized protocols are crucial to further elucidate the clinical significance of PD-L1 expression in VSCCs.

Exploring immune checkpoint inhibitors: Focus on PD-1/PD-L1 axis and beyond

Immunotherapy emerges as a promising approach, marked by recent substantial progress in elucidating how the host immune response impacts tumor development and its sensitivity to various treatments. Immune checkpoint inhibitors have revolutionized cancer therapy by unleashing the power of the immune system to recognize and eradicate tumor cells. Among these, inhibitors targeting the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have garnered significant attention due to their remarkable clinical efficacy across various malignancies. This review delves into the mechanisms of action, clinical applications, and emerging therapeutic strategies surrounding PD-1/PD-L1 blockade. We explore the intricate interactions between PD-1/PD-L1 and other immune checkpoints, shedding light on combinatorial approaches to enhance treatment outcomes and overcome resistance mechanisms. Furthermore, we discuss the expanding landscape of immune checkpoint inhibitors beyond PD-1/PD-L1, including novel targets such as CTLA-4, LAG-3, TIM-3, and TIGIT. Through a comprehensive analysis of preclinical and clinical studies, we highlight the promise and challenges of immune checkpoint blockade in cancer immunotherapy, paving the way for future advancements in the field.

Correlation analysis of DLG5 and PD-L1 expression in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is among the most aggressive forms of breast cancer, characterized by a dismal prognosis. In the absence of drug-targetable receptors, chemotherapy remains the sole systemic treatment alternative. Recent advancements in immunotherapy, particularly immune checkpoint inhibitors (ICIs) that target programmed death 1/programmed death ligand 1 (PD-1/PD-L1) and cytotoxic T lymphocyte associated antigen 4 (CTLA-4), have provided renewed optimism for the treatment of patients with TNBC. Prior research has indicated that the expression level of the cell polarity protein discs large homolog 5 (DLG5) correlates with the malignant progression and prognosis of breast cancer; nevertheless, its influence on PD-L1 expression and its function in immunotherapy for TNBC require further investigation.

METHODS

The hypoxia cell model was established by simulating the cell hypoxic microenvironment in the human SUM159 and MDA-MB-231 cell lines using cobalt II chloride (CoCl2). A combination of PD-L1 inhibitors and DLG5 RNA interference techniques was used, along with various methods including cell counting kit-8 (CCK-8), colony formation, wound healing, transwell migration, reverse transcription-quantitative real-time PCR (RT-qPCR), immunofluorescence, immunohistochemical staining (IHC), expression analysis from datasets and western blotting. These methods were employed to evaluate changes in cell proliferation, migration, and the expression levels of PD-L1 and DLG5. Additionally, the correlation between the expression of PD-L1 and DLG5 in clinical samples was analyzed.

RESULTS

(1) In vitro experiments, a cellular hypoxia model was effectively established utilizing 150 µM CoCl₂. Under these conditions, cell clone formation, invasiveness, and migration rate were all significantly inhibited. (2) The expression levels of DLG5 and PD-L1 were significantly increased in both MDA-MB-231 and SUM159 cells following treatment with 150 µM CoCl₂. (3) Silencing DLG5 resulted in a considerable upregulation of PD-L1 expression in MDA-MB-231 and SUM159 cells under normoxic circumstances, but it was markedly downregulated under hypoxic settings. Inhibition of PD-L1 expression resulted in a considerable increase in DLG5 expression under normoxic conditions, but it decreased under hypoxic conditions. Correlation research demonstrated an inverse association between the expression of DLG5 and PD-L1 in TNBC tissues.

CONCLUSION

This study provides new theoretical evidence and potential therapeutic targets for the immunotherapy strategies of TNBC, holding significant clinical application value.

PD‑1/PD‑L1 inhibitor‑based immunotherapy in locally advanced or metastatic triple‑negative breast cancer: A meta‑analysis

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is negative for oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 expression. Locally advanced and metastatic TNBC not only have a worse prognosis and are more invasive than TNBC, but are also the most immunogenic subtypes of breast cancer. There is still a lack of clarity regarding the optimal treatment of locally advanced or metastatic TNBC. The present study aimed to assess the efficacy and safety of programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitor-based immunotherapy [i.e., immune checkpoint inhibitors (ICIs)] alone or in combination with other therapies for the treatment of locally advanced or metastatic TNBC. The PubMed, Cochrane Library, Embase and MEDLINE databases were searched up to July 19, 2023 to identify studies that examined the efficacy and safety of ICIs for treating TNBC. The primary outcomes were progression-free survival (PFS) and overall survival (OS). The secondary outcomes were safety and adverse events. The data were analysed using Review Manager 5.4. A total of 8 studies (3,338 patients) were included in the present meta-analysis. Compared with other therapies, ICIs had a significantly different effect on OS [hazard ratio (HR)=0.83; 95% confidence interval (CI)=0.69-1.00; P<0.05; I2=59%] in patients with locally advanced or metastatic TNBC. In addition, ICIs significantly prolonged PFS compared with other therapies (intent-to-treat: HR=0.81; 95% CI=0.75-0.88; P<0.00001; I2=0%). Immunotherapy based on PD-1/PD-L1 inhibitors showed variable efficacy on OS and PFS in TNBC, while a significant improvement was observed for PD-L1(+). Future studies should focus on PD-L1 subgroup status, which may help optimize personalized treatment regimens for TNBC.

New Approach in the Interpretation of Complex Triple-negative Breast Cancer Immunohistochemistry Specimens Processed With VENTANA PD-L1 (SP142) Assay

Triple-negative breast cancer (TNBC) is challenging to treat because of its lack of specific molecular targets. The IMMUNOPEG study aimed to evaluate a novel structured method for interpreting TNBC immunohistochemistry specimens processed with VENTANA PD-L1 (SP142) assay. The study involved 10 pathologists who evaluated 50 different immunohistochemistry specimens of TNBC with programmed death ligand 1 (PD-L1) expression considered challenging and that were previously evaluated by the scientific committee, using the NAVIFY Digital Pathology platform. Initially, the overall percent agreement (OPA) was 74%, with a negative percent agreement (NPA) of 68.2% for samples classified as negative, and a positive percent agreement (PPA) of 94.5% for positive samples. After training on the method, the OPA improved significantly to 81.6%, with the NPA increasing to 80.5% and the PPA decreasing to 85.5%. The mean percentage of the tumor area occupied by PD-L1-stained immune cells decreased from 2.5% to 1.6% post-training, approaching to the scientific committee's consensus of 1.029%. The study found that the pathologists' confidence in their assessments increased significantly when using the structured method, which was found to be easy to use by 9 out of 10 pathologists. All pathologists agreed that the structured method was useful for assessing PD-L1 expression. The study suggests that this method has potential value in interpreting challenging cases of PD-L1 immunohistochemistry (IHC) in TNBC. Further refinement and a training protocol may be necessary to enhance the method's efficiency. The potential for generalizing this structured method to other IHC procedures and pathologies warrants additional research.

Inflammation-Triggering Engineered Macrophages (MacTriggers) Enhance Reactivity of Immune Checkpoint Inhibitor Only in Tumor Tissues

Background: We have previously reported engineered macrophages (MacTriggers) that can accelerate the release of tumor necrosis factor-α in response to M2 polarization. MacTriggers are characterized by two original characteristics of macrophages: (1) migration to tumors; and (2) polarization to the M2 phenotype in tumors. Intravenously administered MacTriggers efficiently accumulated in the tumors and induced tumor-specific inflammation. This study reports a novel methodology for enhancing the anti-tumor effects of immune checkpoint inhibitors (ICIs). Results: In this study, we newly found that the intravenously administered MacTriggers in BALB/c mouse models upregulated the expression levels of immune checkpoint proteins, such as programmed cell death (PD)-1 in CD8+ T cells and PD-ligand 1 (PD-L1) in cancer cells and macrophages. Consequently, in two ICI-resistant tumor-inoculated mouse models, the combined administration of MacTrigger and anti-PD-1 antibody (aPD-1) synergistically inhibited tumor growth, whereas monotherapy with aPD-1 did not exhibit anti-tumor effects. This synergistic effect was mainly from aPD-1 enhancing the tumor-attacking ability of CD8+ T cells, which could infiltrate into the tumors following MacTrigger treatment. Importantly, no side effects were observed in normal tissues, particularly in the liver and spleen, indicating that the MacTriggers did not enhance the aPD-1 reactivity in normal tissues. This specificity was from the MacTriggers not polarizing to the M2 phenotype in normal tissues, thereby avoiding inflammation and increased PD-1/PD-L1 expression. MacTriggers could enhance aPD-1 reactivity only in tumors following tumor-specific inflammation induction. Conclusions: Our findings suggest that the MacTrigger and aPD-1 combination therapy is a novel approach for potentially overcoming the current low ICI response rates while avoiding side effects.

BRCA-mutated breast cancer: the unmet need, challenges and therapeutic benefits of genetic testing

Mutations in the BRCA1 and/or BRCA2 genes (BRCAm) increase the risk of developing breast cancer (BC) and are found in ~5% of unselected patients with the disease. BC resulting from a germline BRCAm (gBRCAm) has distinct clinical characteristics along with increased sensitivity to DNA-damaging agents such as poly(ADP-ribose) polymerase (PARP) inhibitors and platinum-based chemotherapies, and potentially decreased sensitivity to cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors. Given the evolving treatment landscape for gBRCAm BC in early and advanced disease settings, timely determination of gBRCAm status is fundamental to facilitate the most effective treatment strategy for patients. However, many patients with gBRCAm are not identified due to suboptimal referral rates and/or a low uptake of genetic testing. We discuss current evidence for a differential response to treatment in patients with gBRCAm in early and advanced BC settings, including outcomes with PARP inhibitors, platinum-based chemotherapies, and CDK4/6 inhibitors, as well as ongoing treatment innovations and the potential of these treatment approaches. Current genetic testing strategies are also examined, including the latest guidelines on who and when to test for gBRCAm, as well as challenges to testing and how these may be overcome.

Recent Advances in Immunotherapy for Breast Cancer: A Review

Breast cancer is one of the most common malignant tumors in women in the world, and its incidence is increasing year by year, which seriously threatens the physical and mental health of women. Triple negative breast cancer (TNBC) is a special molecular type of breast cancer in which estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2 are negative. Compared with other molecular types of breast cancer, triple-negative breast cancer (TNBC) has high aggressiveness and metastasis, high recurrence rate, lack of effective therapeutic targets, and usually poor clinical treatment effect. Chemotherapy was the main therapeutic means used in the past. With the advent of the immune era, immunotherapy has made a lot of progress in the treatment of triple-negative breast cancer (TNBC), bringing new therapeutic hope for the treatment of triple-negative breast cancer. This review combines the results of cutting-edge medical research, mainly summarizes the research progress of immunotherapy, and summarizes the main treatment methods of triple-negative breast cancer (TNBC) immunotherapy, including immune checkpoint inhibitors, tumor vaccines, adoptive immunotherapy and the application of traditional Chinese and western medicine. It provides a new idea for the treatment of triple negative breast cancer (TNBC).

Exploring novel protein-based biomarkers for advancing breast cancer diagnosis: A review

This review provides a contemporary examination of the evolving landscape of breast cancer (BC) diagnosis, focusing on the pivotal role of novel protein-based biomarkers. The overview begins by elucidating the multifaceted nature of BC, exploring its prevalence, subtypes, and clinical complexities. A critical emphasis is placed on the transformative impact of proteomics, dissecting the proteome to unravel the molecular intricacies of BC. Navigating through various sources of samples crucial for biomarker investigations, the review underscores the significance of robust sample processing methods and their validation in ensuring reliable outcomes. The central theme of the review revolves around the identification and evaluation of novel protein-based biomarkers. Cutting-edge discoveries are summarised, shedding light on emerging biomarkers poised for clinical application. Nevertheless, the review candidly addresses the challenges inherent in biomarker discovery, including issues of standardisation, reproducibility, and the complex heterogeneity of BC. The future direction section envisions innovative strategies and technologies to overcome existing challenges. In conclusion, the review summarises the current state of BC biomarker research, offering insights into the intricacies of proteomic investigations. As precision medicine gains momentum, the integration of novel protein-based biomarkers emerges as a promising avenue for enhancing the accuracy and efficacy of BC diagnosis. This review serves as a compass for researchers and clinicians navigating the evolving landscape of BC biomarker discovery, guiding them toward transformative advancements in diagnostic precision and personalised patient care.

Exploring GZMK as a prognostic marker and predictor of immunotherapy response in breast cancer: unveiling novel insights into treatment outcomes

BACKGROUND

Granzyme K (GZMK) is a crucial mediator released by immune cells to eliminate tumor cells, playing significant roles in inflammation and tumorigenesis. Despite its importance, the specific role of GZMK in breast cancer and its mechanisms are not well understood.

METHODS

We utilized data from the TCGA and GEO databases and employed a range of analytical methods including GO, KEGG, GSEA, ssGSEA, and PPI to investigate the impact of GZMK on breast cancer. In vitro studies, including RT-qPCR, CCK-8 assay, cell cycle experiments, apoptosis assays, Celigo scratch assays, Transwell assays, and immunohistochemical methods, were conducted to validate the effects of GZMK on breast cancer cells. Additionally, Cox regression analysis integrating TCGA and our clinical data was used to develop an overall survival (OS) prediction model.

RESULTS

Analysis of clinical pathological features revealed significant correlations between GZMK expression and lymph node staging, differentiation grade, and molecular breast cancer subtypes. High GZMK expression was associated with improved OS, progression-free survival (PFS), and recurrence-free survival (RFS), as confirmed by multifactorial Cox regression analysis. Functional and pathway enrichment analyses of genes positively correlated with GZMK highlighted involvement in lymphocyte differentiation, T cell differentiation, and T cell receptor signaling pathways. A robust association between GZMK expression and T cell presence was noted in the breast cancer tumor microenvironment (TME), with strong correlations with ESTIMATEScore (Cor = 0.743, P < 0.001), ImmuneScore (Cor = 0.802, P < 0.001), and StromalScore (Cor = 0.516, P < 0.001). GZMK also showed significant correlations with immune checkpoint molecules, including CTLA4 (Cor = 0.856, P < 0.001), PD-1 (Cor = 0.82, P < 0.001), PD-L1 (Cor = 0.56, P < 0.001), CD48 (Cor = 0.75, P < 0.001), and CCR7 (Cor = 0.856, P < 0.001). Studies indicated that high GZMK expression enhances patient responsiveness to immunotherapy, with higher levels observed in responsive patients compared to non-responsive ones. In vitro experiments confirmed that GZMK promotes cell proliferation, cell division, apoptosis, cell migration, and invasiveness (P < 0.05).

CONCLUSION

Our study provides insights into the differential expression of GZMK in breast cancer and its potential mechanisms in breast cancer pathogenesis. Elevated GZMK expression is associated with improved OS and RFS, suggesting its potential as a prognostic marker for breast cancer survival and as a predictor of the efficacy of immunotherapy.

IFI30 as a key regulator of PDL1 immunotherapy prognosis in breast cancer

BACKGROUND

IFI30 is a lysosomal thiol reductase involved in antigen presentation and immune regulation in various cancers, including breast cancer. Despite its known involvement, the precise mechanism, function, and relationship with the PD-L1 axis and immune response remain unclear.

METHODS

We conducted an extensive investigation into IFI30 mRNA expression in breast cancer utilizing data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. Furthermore, we characterized IFI30 mRNA expression across various cell types using publicly available single-cell RNA sequencing datasets, and assessed protein expression through immunohistochemistry using an in-house breast cancer tissue microarray. Functional experiments were performed to elucidate the effects of IFI30 overexpression on PD-L1 expression and inhibitory efficacy in both macrophages and breast tumor cells.

RESULTS

Our study unveiled a marked upregulation of IFI30 expression in breast cancer tissues compared to their normal counterparts, with notable associations identified with tumor stage and prognosis. Additionally, IFI30 expression demonstrated significant correlations with various immune-related signaling pathways, encompassing peptide antigen binding, cytokine binding, and MHC class II presentation. Notably, breast cancer samples exhibiting high IFI30 expression in tumor cells displayed high PD-L1 expression on corresponding cells, alongside a diminished ratio of CD8 + T cell infiltration within the tumor microenvironment. Furthermore, ectopic knockdown of IFI30 in both tumor cells and macrophages resulted in a reduction of PD-L1 expression, while conversely, overexpression of IFI30 led to an increase in PD-L1 expression.

CONCLUSIONS

This study offers new insights into the involvement of IFI30 in breast cancer, elucidating its interplay with the PD-L1 axis and immune response dynamics. Our findings suggest that modulation of the IFI30-PD-L1 axis could serve as a promising strategy for regulating T cells infiltration in breast cancer thus treating breast cancer.

Molecular classification and biomarkers of outcome with immunotherapy in extensive-stage small-cell lung cancer: analyses of the CASPIAN phase 3 study

BACKGROUND

We explored potential predictive biomarkers of immunotherapy response in patients with extensive-stage small-cell lung cancer (ES-SCLC) treated with durvalumab (D) + tremelimumab (T) + etoposide-platinum (EP), D + EP, or EP in the randomized phase 3 CASPIAN trial.

METHODS

805 treatment-naïve patients with ES-SCLC were randomized (1:1:1) to receive D + T + EP, D + EP, or EP. The primary endpoint was overall survival (OS). Patients were required to provide an archived tumor tissue block (or ≥ 15 newly cut unstained slides) at screening, if these samples existed. After assessment for programmed cell death ligand-1 expression and tissue tumor mutational burden, residual tissue was used for additional molecular profiling including by RNA sequencing and immunohistochemistry.

RESULTS

In 182 patients with transcriptional molecular subtyping, OS with D ± T + EP was numerically highest in the SCLC-inflamed subtype (n = 10, median 24.0 months). Patients derived benefit from immunotherapy across subtypes; thus, additional biomarkers were investigated. OS benefit with D ± T + EP versus EP was greater with high versus low CD8A expression/CD8 cell density by immunohistochemistry, but with no additional benefit with D + T + EP versus D + EP. OS benefit with D + T + EP versus D + EP was associated with high expression of CD4 (median 25.9 vs. 11.4 months) and antigen-presenting and processing machinery (25.9 vs. 14.6 months) and MHC I and II (23.6 vs. 17.3 months) gene signatures, and with higher MHC I expression by immunohistochemistry.

CONCLUSIONS

These findings demonstrate the tumor microenvironment is important in mediating better outcomes with D ± T + EP in ES-SCLC, with canonical immune markers associated with hypothesized immunotherapy mechanisms of action defining patient subsets that respond to D ± T.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03043872.

Exploring the Immunological Profile in Breast Cancer: Recent Advances in Diagnosis and Prognosis through Circulating Tumor Cells

This review offers a comprehensive exploration of the intricate immunological landscape of breast cancer (BC), focusing on recent advances in diagnosis and prognosis through the analysis of circulating tumor cells (CTCs). Positioned within the broader context of BC research, it underscores the pivotal role of the immune system in shaping the disease's progression. The primary objective of this investigation is to synthesize current knowledge on the immunological aspects of BC, with a particular emphasis on the diagnostic and prognostic potential offered by CTCs. This review adopts a thorough examination of the relevant literature, incorporating recent breakthroughs in the field. The methodology section succinctly outlines the approach, with a specific focus on CTC analysis and its implications for BC diagnosis and prognosis. Through this review, insights into the dynamic interplay between the immune system and BC are highlighted, with a specific emphasis on the role of CTCs in advancing diagnostic methodologies and refining prognostic assessments. Furthermore, this review presents objective and substantiated results, contributing to a deeper understanding of the immunological complexity in BC. In conclusion, this investigation underscores the significance of exploring the immunological profile of BC patients, providing valuable insights into novel advances in diagnosis and prognosis through the utilization of CTCs. The objective presentation of findings emphasizes the crucial role of the immune system in BC dynamics, thereby opening avenues for enhanced clinical management strategies.

Unlocking c-MET: A comprehensive journey into targeted therapies for breast cancer

Breast cancer is the most common malignancy among women, posing a formidable health challenge worldwide. In this complex landscape, the c-MET (cellular-mesenchymal epithelial transition factor) receptor tyrosine kinase (RTK), also recognized as the hepatocyte growth factor (HGF) receptor (HGFR), emerges as a prominent protagonist, displaying overexpression in nearly 50% of breast cancer cases. Activation of c-MET by its ligand, HGF, secreted by neighboring mesenchymal cells, contributes to a cascade of tumorigenic processes, including cell proliferation, metastasis, angiogenesis, and immunosuppression. While c-MET inhibitors such as crizotinib, capmatinib, tepotinib and cabozantinib have garnered FDA approval for non-small cell lung cancer (NSCLC), their potential within breast cancer therapy is still undetermined. This comprehensive review embarks on a journey through structural biology, multifaceted functions, and intricate signaling pathways orchestrated by c-MET across cancer types. Furthermore, we highlight the pivotal role of c-MET-targeted therapies in breast cancer, offering a clinical perspective on this promising avenue of intervention. In this pursuit, we strive to unravel the potential of c-MET as a beacon of hope in the fight against breast cancer, unveiling new horizons for therapeutic innovation.

The predictive value of PD-L1 expression in response to anti-PD-1/PD-L1 therapy for biliary tract cancer: a systematic review and meta-analysis

BACKGROUND

Recently, anti-programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunotherapy offers promising results for advanced biliary tract cancer (BTC). However, patients show highly heterogeneous responses to treatment, and predictive biomarkers are lacking. We performed a systematic review and meta-analysis to assess the potential of PD-L1 expression as a biomarker for treatment response and survival in patients with BTC undergoing anti-PD-1/PD-L1 therapy.

METHODS

We conducted a comprehensive systematic literature search through June 2023, utilizing the PubMed, EMBASE, and Cochrane Library databases. The outcomes of interest included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) according to PD-L1 expression. Subgroup analyses and meta-regression were performed to identify possible sources of heterogeneity.

RESULTS

A total of 30 studies was included in the final analysis. Pooled analysis showed no significant differences in ORR (odds ratio [OR], 1.56; 95% confidence intervals [CIs], 0.94-2.56) and DCR (OR, 1.84; 95% CIs, 0.88-3.82) between PD-L1 (+) and PD-L1 (-) patients. In contrast, survival analysis showed improved PFS (hazard ratio [HR], 0.54, 95% CIs, 0.41-0.71) and OS (HR, 0.58; 95% CI, 0.47-0.72) among PD-L1 (+) patients compared to PD-L1 (-) patients. Sensitivity analysis excluding retrospective studies showed no significant differences with the primary results. Furthermore, meta-regression demonstrated that drug target (PD-1 vs. PD-L1), presence of additional intervention (monotherapy vs. combination therapy), and PD-L1 cut-off level (1% vs. ≥5%) significantly affected the predictive value of PD-L1 expression.

CONCLUSION

PD-L1 expression might be a helpful biomarker for predicting PFS and OS in patients with BTC undergoing anti-PD-1/PD-L1 therapy. The predictive value of PD-L1 expression can be significantly influenced by diagnostic or treatment variables.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023434114.

CXCL13 Positive Cells Localization Predict Response to Anti-PD-1/PD-L1 in Pulmonary Non-Small Cell Carcinoma

Background: Immune checkpoint inhibitors (ICIs) have revolutionized non-small cell lung cancers (NSCLCs) treatment, but only 20-30% of patients benefit from these treatments. Currently, PD-L1 expression in tumor cells is the only clinically approved predictor of ICI response in lung cancer, but concerns arise due to its low negative and positive predictive value. Recent studies suggest that CXCL13+ T cells in the tumor microenvironment (TME) may be a good predictor of response. We aimed to assess if CXCL13+ cell localization within the TME can predict ICI response in advanced NSCLC patients. Methods: This retrospective study included 65 advanced NSCLC patients treated with Nivolumab/Pembrolizumab at IUCPQ or CHUM and for whom a pretreatment surgical specimen was available. Good responders were defined as having a complete radiologic response at 1 year, and bad responders were defined as showing cancer progression at 1 year. IHC staining for CXCL13 was carried out on a representative slide from a resection specimen, and CXCL13+ cell density was evaluated in tumor (T), invasive margin (IM), non-tumor (NT), and tertiary lymphoid structure (TLS) compartments. Cox models were used to analyze progression-free survival (PFS) and overall survival (OS) probability, while the Mann-Whitney test was used to compare CXCL13+ cell density between responders and non-responders. Results: We showed that CXCL13+ cell density localization within the TME is associated with ICI efficacy. An increased density of CXCL13+ cells across all compartments was associated with a poorer prognostic (OS; HR = 1.22; 95%CI = 1.04-1.42; p = 0.01, PFS; HR = 1.16; p = 0.02), or a better prognostic when colocalized within TLSs (PFS; HR = 0.84, p = 0.03). Conclusion: Our results support the role of CXCL13+ cells in advanced NSCLC patients, with favorable prognosis when localized within TLSs and unfavorable prognosis when present elsewhere. The concomitant proximity of CXCL13+ and CD20+ cells within TLSs may favor antigen presentation to T cells, thus enhancing the effect of PD-1/PD-L1 axis inhibition. Further validation is warranted to confirm the potential relevance of this biomarker in a clinical setting.

Circadian lifestyle determinants of immune checkpoint inhibitor efficacy

Immune Checkpoint Inhibitors (ICI) have revolutionised cancer care in recent years. Despite a global improvement in the efficacy and tolerability of systemic anticancer treatments, a sizeable proportion of patients still do not benefit maximally from ICI. Extensive research has been undertaken to reveal the immune- and cancer-related mechanisms underlying resistance and response to ICI, yet more limited investigations have explored potentially modifiable lifestyle host factors and their impact on ICI efficacy and tolerability. Moreover, multiple trials have reported a marked and coherent effect of time-of-day ICI administration and patients' outcomes. The biological circadian clock indeed temporally controls multiple aspects of the immune system, both directly and through mediation of timing of lifestyle actions, including food intake, physical exercise, exposure to bright light and sleep. These factors potentially modulate the immune response also through the microbiome, emerging as an important mediator of a patient's immune system. Thus, this review will look at critically amalgamating the existing clinical and experimental evidence to postulate how modifiable lifestyle factors could be used to improve the outcomes of cancer patients on immunotherapy through appropriate and individualised entrainment of the circadian timing system and temporal orchestration of the immune system functions.

Advances in Doxorubicin-based nano-drug delivery system in triple negative breast cancer

Triple positive breast cancer (TPBC) is one of the most aggressive breast cancer. Due to the unique cell phenotype, aggressiveness, metastatic potential and lack of receptors or targets, chemotherapy is the choice of treatment for TNBC. Doxorubicin (DOX), one of the representative agents of anthracycline chemotherapy, has better efficacy in patients with metastatic TNBC (mTNBC). DOX in anthracycline-based chemotherapy regimens have higher response rates. Nano-drug delivery systems possess unique targeting and ability of co-load, deliver and release chemotherapeutic drugs, active gene fragments and immune enhancing factors to effectively inhibit or kill tumor cells. Therefore, advances in nano-drug delivery systems for DOX therapy have attracted a considerable amount of attention from researchers. In this article, we have reviewed the progress of nano-drug delivery systems (e.g., Nanoparticles, Liposomes, Micelles, Nanogels, Dendrimers, Exosomes, etc.) applied to DOX in the treatment of TNBC. We also summarize the current progress of clinical trials of DOX combined with immune checkpoint inhibitors (ICIS) for the treatment of TNBC. The merits, demerits and future development of nanomedicine delivery systems in the treatment of TNBC are also envisioned, with the aim of providing a new class of safe and efficient thoughts for the treatment of TNBC.

Triple-negative breast cancer: from none to multiple therapeutic targets in two decades

Triple-negative breast cancers (TNBCs) are more likely to occur in younger patients and have a poor prognosis. They are highly heterogeneous tumors consisting of different molecular subtypes. The only common characteristic among them is the absence of targets for endocrine therapy and human epidermal growth factor receptor 2 (HER2) blockade. In the past two decades, there has been an increased understanding of these tumors from a molecular perspective, leading to their stratification according to new therapeutic strategies. TNBC has ushered breast carcinomas into the era of immunotherapy. The higher frequency of germline BRCA mutations in these tumors enables targeting this repair defect by drugs like PARP inhibitors, resulting in synthetic lethality in neoplastic cells. Additionally, we have the identification of new molecules to which this generation of smart drugs, such as antibody-drug conjugates (ADCs), are directed. In this review, we will discuss the trajectory of this knowledge in a systematic manner, presenting the molecular bases, therapeutic possibilities, and biomarkers.

Immunohistological analysis of B7-H4, IDO1, and PD-L1 expression and tumor immune microenvironment based on triple-negative breast cancer subtypes

BACKGROUND

B7 homolog 4 (B7-H4) and indoleamine 2,3-dioxygenase (IDO1) are factors involved in the inhibition of antitumor activity and are new therapeutic targets for immune checkpoint therapy. Our study aimed to simultaneously investigate the interrelationship among B7-H4, IDO1 and programmed cell death ligand 1 (PD-L1) expression in triple-negative breast cancer (TNBC), including tumor immune microenvironment (TIME) and TNBC subtypes.

METHODS

Immunostaining for PD-L1, B7-H4, and IDO1 was performed on whole-slide sections of 119 cases of TNBC. The TIME was evaluated based on stromal tumor infiltrating lymphocytes (sTILs; %), pattern classification of TILs, tumor-stroma ratio (TSR), and tertiary lymphoid structure (TLS). TNBC subtypes were also determined by immunohistochemistry analysis of cytokeratin 5/6 and androgen receptor (AR) expression.

RESULTS

B7-H4 expression was significantly higher in cases with a combined positive score cutoff of 5 for PD-L1 (clone 28-8; p = 0.021), inflamed TIL pattern (p = 0.007), and TLS ≥ 4 (p = 0.006). B7-H4 expression was higher in case of CK5/6 ≥ 10 (p = 0.035). The H-scores of AR and B7-H4 were inversely correlated (ρ = - 0.509, p < 0.001). B7-H4 and IDO1 expression levels were inversely correlated in cases with AR < 10 (ρ = - 0.354, p < 0.001).

CONCLUSIONS

These results suggest that considering the TIL pattern and TLS and identifying the expression of PD-L1 and the basal-like type are useful for estimating B7-H4 expression. In addition, luminal androgen receptor (LAR)-type is frequently deficient in B7-H4 expression. In non-LAR types, B7-H4 and IDO1 expression are exclusive.