Metastatic sites as predictors in advanced NSCLC treated with PD-1 inhibitors: a systematic review and meta-analysis

Combining dynamics of serum inflammatory and nutritional indicators as novel biomarkers in immune checkpoint inhibitor treatment of non-small-cell lung cancer with bone metastases

OBJECTIVES

We aimed to investigate the association of the dynamics of serum inflammatory and nutritional indicators with immune checkpoint inhibitor (ICI) response in non-small-cell lung cancer (NSCLC) with bone metastases, and to develop a novel predictive scoring system based on these indicators.

METHODS

Patients with NSCLC having bone metastases treated with ICIs were categorized as: the development cohort (January 2016 to March 2021, n = 60) and the validation cohort (April 2021 to June 2023, n = 40). Serum indicators of inflammation and nutrition such as C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), albumin, prognostic nutritional index (PNI) were investigated before and six weeks after ICI initiation. The correlations of these dynamics with bone metastasis response rate (BoMRR) and overall survival (OS) were analyzed. A scoring system consisting of independent predictors was developed (IMMUNO-SCORE) and correlations with clinical outcomes were validated using the validation cohort.

RESULTS

In the development cohort, multivariable analysis showed that NLR and PNI dynamics and CRP, NLR, and PNI dynamics were independent predictors of BoMRR and OS, respectively. The IMMUNO-SCORE consisting of NLR and PNI dynamics, which were the common predictors of the clinical outcomes, was significantly correlated with BoMRR (p < 0.01) and OS (p < 0.001) in cross-validation. The area under the curve of the score (0.786) was higher than individual NLR and PNI dynamics (0.72 and 0.684).

CONCLUSION

Dynamics in NLR and PNI were demonstrated as biomarkers of treatment response and prognosis in ICI treatment of NSCLC with bone metastases, and the score combining these biomarkers was significantly correlated with clinical outcomes.

A Pathologically Friendly Strategy for Determining the Organ-specific Spatial Tumor Microenvironment Topology in Lung Adenocarcinoma Through the Integration of snRandom-seq and Imaging Mass Cytometry

Heterogeneous organ-specific responses to immunotherapy exist in lung cancer. Dissecting tumor microenvironment (TME) can provide new insights into the mechanisms of divergent responses, the process of which remains poor, partly due to the challenges associated with single-cell profiling using formalin-fixed paraffin-embedded (FFPE) materials. In this study, single-cell nuclei RNA sequencing and imaging mass cytometry (IMC) are used to dissect organ-specific cellular and spatial TME based on FFPE samples from paired primary lung adenocarcinoma (LUAD) and metastases. Single-cell analyses of 84 294 cells from sequencing and 250 600 cells from IMC reveal divergent organ-specific immune niches. For sites of LUAD responding well to immunotherapy, including primary LUAD and adrenal gland metastases, a significant enrichment of B, plasma, and T cells is detected. Spatially resolved maps reveal cellular neighborhoods recapitulating functional units of the tumor ecosystem and the spatial proximity of B and CD4+ T cells at immunogenic sites. Various organ-specific densities of tertiary lymphoid structures are observed. Immunosuppressive sites, including brain and liver metastases, are deposited with collagen I, and T cells at these sites highly express TIM-3. This study originally deciphers the single-cell landscape of the organ-specific TME at both cellular and spatial levels for LUAD, indicating the necessity for organ-specific treatment approaches.

What enlightenment has the development of lung cancer bone metastasis brought in the last 22 years

BACKGROUND

Lung cancer bone metastasis (LCBM) is a disease with a poor prognosis, high risk and large patient population. Although considerable scientific output has accumulated on LCBM, problems have emerged, such as confusing research structures.

AIM

To organize the research frontiers and body of knowledge of the studies on LCBM from the last 22 years according to their basic research and translation, clinical treatment, and clinical diagnosis to provide a reference for the development of new LCBM clinical and basic research.

METHODS

We used tools, including R, VOSviewer and CiteSpace software, to measure and visualize the keywords and other metrics of 1903 articles from the Web of Science Core Collection. We also performed enrichment and protein-protein interaction analyses of gene expression datasets from LCBM cases worldwide.

RESULTS

Research on LCBM has received extensive attention from scholars worldwide over the last 20 years. Targeted therapies and immunotherapies have evolved into the mainstream basic and clinical research directions. The basic aspects of drug resistance mechanisms and parathyroid hormone-related protein may provide new ideas for mechanistic study and improvements in LCBM prognosis. The produced molecular map showed that ribosomes and focal adhesion are possible pathways that promote LCBM occurrence.

CONCLUSION

Novel therapies for LCBM face animal testing and drug resistance issues. Future focus should centre on advancing clinical therapies and researching drug resistance mechanisms and ribosome-related pathways.

Advanced non-squamous NSCLC with no actionable oncogenic driver in Spain: a cross-sectional descriptive analysis of data from the Thoracic Tumor Registry

BACKGROUND

Non-small cell lung cancer (NSCLC) accounts for the vast majority of all diagnosed lung cancers. According to their histology, most NSCLCs are considered non-squamous cell carcinoma (NSCC), and up to 85% of the latter may lack either one of the two main actionable oncogenic drivers (i.e., EGFR mutations and ALK rearrangements).

OBJECTIVE

Our analysis aimed to describe the clinical and epidemiological characteristics of Spanish patients suffering from NSCC with no actionable oncogenic driver in daily clinical practice.

DESIGN

A retrospective, cross-sectional, descriptive analysis.

METHODS

We analyzed the records of all Spanish patients with advanced NSCC diagnosed between January 2011 and January 2020 and included in the Spanish Thoracic Tumor Registry database. We evaluated the presence of metastasis and molecular profiling at the time of diagnosis and treatments received. We also assessed overall survival (OS) and progression-free survival (PFS) according to first-line treatment.

RESULTS

One thousand seven hundred ninety-seven Spanish patients with NSCC were included. They were mainly men (73.2%), smokers (current [44.4%] and former [44.4%]) and presented adenocarcinoma histology (97.6%). Most patients had at least one comorbidity (80.4%) and one metastatic site (96.8%), and a non-negligible number of those tested were PD-L1 positive (35.2%). Notably, the presence of liver metastasis indicated a shorter median OS and PFS than metastasis in other locations (p < 0.001). Chemotherapy was more often prescribed than immunotherapy as first-, second-, and third-line treatment in that period. In first-line, the OS rates were similar in patients receiving either regimen, but PFS rates significantly better in patients treated with immunotherapy (p = 0.026). Also, a high number of patients did not reach second- and third-line treatment, suggesting the failure of current early diagnostic measures and therapies.

CONCLUSIONS

This analysis of the most lethal tumor in Spain could highlight the strengths and the weaknesses of its clinical management and set the ground for further advances and research.

Poor efficacy of immune checkpoint inhibitor treatment in advanced thymic carcinoma patients with liver metastases

Background

Although immune checkpoint inhibitor treatment for advanced thymic carcinoma exhibits promising efficacy, factors that affect the efficacy and prognosis, including metastases sites, remain uncertain.

Objectives

Our study aimed to investigate the determinants of survival among patients with advanced thymic carcinoma who underwent immunotherapy in real-world settings, with implications for clinical practice.

Designs

Different therapy regimens of immunotherapy were produced to analyze the influence of liver metastases on survival and prognosis for advanced thymic carcinoma patients.

Methods

Data for advanced thymic carcinoma patients receiving immunotherapy and their metastases sites were collected for analysis from seven different hospitals between January 2015 and January 2023. Progression-free survival (PFS) and overall survival (OS) analyses were performed using the Kaplan-Meier method. Cox analysis was used to evaluate factors influencing survival.

Results

The present study analyzed 136 advanced thymic carcinoma patients from seven different hospitals.The PFS for all patients receiving immunotherapy was 6.4 months, while the OS was 24.0 months. The objective response rate was different for patients with liver and non-liver metastases (11.9% versus 37.2%, p = 0.003). The disease control rate values were also different between the two groups (47.6% versus 80.9%, p = 0.037). The PFS for patients with liver metastases demonstrated poor immunotherapy efficacy compared to patients with non-liver metastases (3.0 versus 8.0 months, p < 0.0001). The OS was also significantly different between these two patient groups (16.1 versus 29.1 months, p = 0.009).

Conclusion

Immunotherapy had poor efficacy in advanced thymic carcinoma patients with liver metastases.

Impact of bone metastasis on the prognosis of non-small cell lung cancer patients treated with immune checkpoint inhibitors: a systematic review and meta-analysis

BACKGROUND

This review was implemented to examine the impact of bone metastasis on the prognosis of non-small cell lung cancer patients (NSCLC) treated with immune checkpoint inhibitors (ICIs).

METHODS

A literature search was conducted in the PubMed, CENTRAL, Web of Science, and Embase databases up to 4th September 2022. Multivariable adjusted data were pooled in a random-effects model.

RESULTS

13 studies were included. On a combined analysis of 10 studies, it was noted that bony metastasis was associated with poor overall survival (OS) in NSCLC patients treated with ICIs (HR: 1.55 95% CI 1.24, 1.94 I2 = 69% p = 0.001). Meta-analysis of seven studies showed that bony metastasis was not associated with poor progression-free survival (PFS) in NSCLC patients treated with ICIs (HR: 1.31 95% CI 0.85, 2.01 I2 = 85% p = 0.22). Meta-regression analysis using the moderator's age, male gender, smoking history, squamous histology, and ICI as 1st line therapy for the outcome OS was not statistically significant.

CONCLUSION

The presence of bone metastasis is a predictor of poor OS in NSCLC treated with ICIs. However, PFS does not seem to be influenced by the presence of bone metastasis. Clinicians should prioritize the management of NSCLC patients with bone metastasis and explore the use of combination therapies to achieve optimal results. Further studies taking into account different combination therapies for such patients would strengthen the evidence.

Metastatic site and clinical outcome of patients with deficient mismatch repair metastatic colorectal cancer treated with an immune checkpoint inhibitor in the first-line setting

PURPOSE

Only one-half of deficient mismatch repair (d-MMR) metastatic colorectal cancers (mCRC) demonstrate durable responses to immune checkpoint inhibitors (ICIs). Given preclinical data indicating that liver metastases sequester activated CD8+ T cells from systemic circulation, we examined clinical outcome by metastatic site.

PATIENTS AND METHODS

In a retrospective cohort of patients with d-MMR mCRCs treated at multiple centers in France (n = 66), we sought to validate data from a U.S. cohort, and performed pooled analysis (n = 104). All patients received first-line ICI monotherapy. Metastatic site was analyzed in relationship to tumor response (RECIST version 1.1), and with progression-free survival (PFS) by multivariable stratified Cox regression after adjustment for covariates.

RESULTS

Objective responses were achieved in 38/66 (58%) of patients in the validation cohort. Best tumor response included 13 (20%) complete responses (CR), 25 (38%) partial responses (PR), 16 (25%) stable disease, and 11 (17%) progressive disease (PD). One-year and 5-year PFS rates were 73% and 67%, respectively; 18 (27%) patients progressed during immunotherapy. Best tumor response was attenuated in patients with liver metastasis (P = 0.03). Presence of liver metastasis, but not other sites, was associated with significantly poorer PFS after adjustment for covariates (HRadj 2.82; 95%CI, 1.08-7.39; Padj=0.03). In a pooled analysis, liver metastasis remained significantly and independently associated with poorer PFS (HRadj 3.18; 95%CI, 1.52-6.67; Padj=0.002) and with attenuated tumor best response (P = 0.01).

CONCLUSIONS

Metastasis to the liver, but not other sites, was validated as an independent factor associated with poorer response and survival after ICI treatment in d-MMR mCRCs. These data underscore the need for novel therapeutic strategies in these patients.

Development and validation of a nomogram for predicting the overall survival in non-small cell lung cancer patients with liver metastasis

Background

Among all metastatic lesions in non-small cell lung cancer (NSCLC), liver metastasis (LM) is the most lethal site with a median survival of less than 5 months. Few studies exclusively report on prognostic factors for these unique patients. We aimed to construct and validate a practical model to predict the prognosis of NSCLC patients with LM.

Methods

Cases of NSCLC with LM diagnosed between 2010 and 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database, and were randomly split into training and validation cohort (7:3). The overall survival (OS) was measured from diagnosis until date of death or last follow-up. Cox regression analyses were performed to identify potential predictors of the model. A nomogram incorporating those independent factors was constructed and validated by the concordance index (C-index) and calibration plots. The decision curve analysis (DCA) and a risk stratification system were used to evaluate its clinical value.

Results

A total of 2,367 cases were selected for analysis and randomized to the training cohort (n=1,677) and the validation cohort (n=690). The patients were mainly male (59.3%), married (83.1%) and White (77.3%). Apart from LM, 54.2%, 26.7%, and 36.7% of patients also present with bone, brain, and lung metastases, respectively. The median follow-up was 4.0 months for all patients and 23 months for alive cases. The median OS was 5 months [interquartile range (IQR), 2-11 months]. Sex, age, race, grade, T stage, bone metastasis, brain metastasis, surgery, and chemotherapy were identified as the independent risk factors of the OS and used to develop the nomogram. The calibration curves exhibited excellent agreement between the predicted and actual survival in both the training and validation set, with a C-index of 0.700 [95% confidence interval (CI): 0.684-0.716] and 0.677 (95% CI: 0.653-0.701), respectively. The DCA and the risk classification system further supported that the prediction model was clinically effective.

Conclusions

This is the first study to build a prediction model for NSCLC patients with LM. It aids in treatment decisions, focused care, and physician-patient communication. The global prospective data is needed to further improve this model.

A multistate modeling and simulation framework to learn dose-response of oncology drugs: Application to bintrafusp alfa in non-small cell lung cancer

The dose/exposure-efficacy analyses are often conducted separately for oncology end points like best overall response, progression-free survival (PFS) and overall survival (OS). Multistate models offer to bridge these dose-end point relationships by describing transitions and transition times from enrollment to response, progression, and death, and evaluating transition-specific dose effects. This study aims to apply the multistate pharmacometric modeling and simulation framework in a dose optimization setting of bintrafusp alfa, a fusion protein targeting TGF-β and PD-L1. A multistate model with six states (stable disease [SD], response, progression, unknown, dropout, and death) was developed to describe the totality of endpoints data (time to response, PFS, and OS) of 80 patients with non-small cell lung cancer receiving 500 or 1200 mg of bintrafusp alfa. Besides dose, evaluated predictor of transitions include time, demographics, premedication, disease factors, individual clearance derived from a pharmacokinetic model, and tumor dynamic metrics observed or derived from tumor size model. We found that probabilities of progression and death upon progression decreased over time since enrollment. Patients with metastasis at baseline had a higher probability to progress than patients without metastasis had. Despite dose failed to be statistically significant for any individual transition, the combined effect quantified through a model with dose-specific transition estimates was still informative. Simulations predicted a 69.2% probability of at least 1 month longer, and, 55.6% probability of at least 2-months longer median OS from the 1200 mg compared to the 500 mg dose, supporting the selection of 1200 mg for future studies.

Real-world outcomes in patients with KRAS G12C-mutated advanced non-small cell lung cancer treated with docetaxel in second-line or beyond

INTRODUCTION

The KRAS G12C mutation has recently become a druggable target in non-small cell lung cancer (NSCLC). In this observational study, we present real-world clinicopathological characteristics, treatment patterns, and survival outcomes data in patients with KRAS mutation-positive advanced NSCLC (aNSCLC), including those with KRAS G12C and KRAS non-G12C mutations, who received docetaxel as standard-of-care treatment in the second-line and beyond (2L+).

METHODS

US-based electronic health record-derived de-identified databases were used to assess clinicopathological characteristics and outcomes in adult aNSCLC patients with KRAS mutations treated with 2L+ docetaxel between January 1, 2011, and March 31, 2021. The primary endpoints were median real-world overall survival OS (rwOS) and median real-world progression-free survival (rwPFS), which were estimated in 2L, third-line, fourth-line, and 2L+ analysis sets among patients who had a 6-month minimum opportunity for follow-up and were not taking a clinical trial drug.

RESULTS

Of the 677 patients with KRAS-mutant aNSCLC (KRAS mutant cohort) treated with 2L+ docetaxel, 295 (43.6%) had KRAS G12C mutation (KRAS G12C cohort) and 382 (56.4%) had KRAS non-G12C mutation (KRAS non-G12C cohort). Across all cohorts, approximately 47%, 35%, 14-15%, and 6-9% of patients received 2L, third-line, fourth-line, and fifth- or later-line docetaxel, respectively. In the KRAS G12C cohort, ∼68% of patients were treated with a PD-1/PD-L1 inhibitor prior to 2L+ docetaxel. Most 2L+ docetaxel regimens in the KRAS G12C cohort were combinations (59.5%), primarily with ramucirumab (45.2%). In the KRAS G12C cohort, the median rwOS and median rwPFS after 2L+ docetaxel were 6.0 (95% CI, 4.9-7.1) and 3.4 (95% CI, 2.7-4.2) months, respectively, with similar trends observed in other cohorts and lines of therapy.

CONCLUSIONS

Real-world outcomes were poor in patients with KRAS G12C-mutated aNSCLC treated with 2L+ docetaxel. Targeted and more efficacious treatment options in these patients are warranted.

Efficacy and safety of immune checkpoint inhibitors for hepatocellular carcinoma patients with macrovascular invasion or extrahepatic spread: a systematic review and meta-analysis of 54 studies with 6187 hepatocellular carcinoma patients

BACKGROUND AND AIMS

The impacts of macrovascular invasion (MVI) or extrahepatic spread (EHS) on the efficacy and safety of immune checkpoint inhibitors (ICIs) among hepatocellular carcinoma (HCC) patients remain unclear. Thus, we conducted a systematic review and meta-analysis to clarify whether ICI therapy is a feasible treatment option for HCC with MVI or EHS.

METHODS

Eligible studies published before September 14, 2022, were retrieved. In this meta-analysis, the objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and occurrence of adverse events (AEs) were outcomes of interest.

RESULTS

Fifty-four studies involving 6187 individuals were included. The findings indicated that the presence of EHS in ICI-treated HCC patients may indicate an inferior ORR (OR 0.77, 95% CI 0.63-0.96), but may not significantly affect the PFS (multivariate analyses: HR 1.27, 95% CI 0.70-2.31) and OS (multivariate analyses: HR 1.23, 95% CI 0.70-2.16). Additionally, the presence of MVI in ICI-treated HCC patients may not have significant prognostic impact on ORR (OR 0.84, 95% CI 0.64-1.10), but may indicate inferior PFS (multivariate analyses: HR 1.75, 95% CI 1.07-2.84) and OS (multivariate analyses: HR 2.03, 95% CI 1.31-3.14). The presence of EHS or MVI in ICI-treated HCC patients may not significantly impact the occurrence of any serious immune-related adverse events (irAEs) (grades ≥ 3) (EHS: OR 0.44, 95% CI 0.12-1.56; MVI: OR 0.68, 95% CI 0.24-1.88).

CONCLUSION

The presence of MVI or EHS in ICI-treated HCC patients may not significantly impact the occurrence of serious irAEs. However, the presence of MVI (but not EHS) in ICI-treated HCC patients may be a significant negative prognostic factor. Therefore, ICI-treated HCC patients with MVI warrant more attention.

Choosing the optimal immunotherapeutic strategies for non-small cell lung cancer based on clinical factors

The treatment landscape of advanced non-small cell lung cancer (NSCLC) has changed dramatically since the emergence of immune checkpoint inhibitors (ICIs). Although some patients achieve long survival with relatively mild toxicities, not all patients experience such benefits from ICI treatment. There are several ways to use ICIs in NSCLC patients, including monotherapy, combination immunotherapy, and combination chemoimmunotherapy. Decision-making in the selection of an ICI treatment regimen for NSCLC is complicated partly because of the absence of head-to-head prospective comparisons. Programmed death-ligand 1 (PD-L1) expression is currently considered a standard biomarker for predicting the efficacy of ICIs, although some limitations exist. In addition to the PD-L1 tumor proportion score, many other clinical factors should also be considered to determine the optimal treatment strategy for each patient, including age, performance status, histological subtypes, comorbidities, status of oncogenic driver mutation, and metastatic sites. Nevertheless, evidence of the efficacy and safety of ICIs with some specific conditions of these factors is insufficient. Indeed, patients with poor performance status, oncogenic driver mutations, or interstitial lung disease have frequently been set as ineligible in randomized clinical trials of NSCLC. ICI use in these patients is controversial and remains to be discussed. It is important to select patients for whom ICIs can benefit the most from these populations. In this article, we review previous reports of clinical trials or experience in using ICIs in NSCLC, focusing on several clinical factors that are associated with treatment outcomes, and then discuss the optimal ICI treatment strategies for NSCLC.

Organ-specific metastatic landscape dissects PD-(L)1 blockade efficacy in advanced non-small cell lung cancer: applicability from clinical trials to real-world practice

BACKGROUND

Organ-specific metastatic context has not been incorporated into the clinical practice of guiding programmed death-(ligand) 1 [PD-(L)1] blockade, due to a lack of understanding of its predictive versus prognostic value. We aim at delineating and then incorporating both the predictive and prognostic effects of the metastatic-organ landscape to dissect PD-(L)1 blockade efficacy in non-small cell lung cancer (NSCLC).

METHODS

A total of 2062 NSCLC patients from a double-arm randomized trial (OAK), two immunotherapy trials (FIR, BIRCH), and a real-world cohort (NFyy) were included. The metastatic organs were stratified into two categories based on their treatment-dependent predictive significance versus treatment-independent prognosis. A metastasis-based scoring system (METscore) was developed and validated for guiding PD-(L)1 blockade in clinical trials and real-world practice.

RESULTS

Patients harboring various organ-specific metastases presented significantly different responses to immunotherapy, and those with brain and adrenal gland metastases survived longer than others [overall survival (OS), p = 0.0105; progression-free survival (PFS), p = 0.0167]. In contrast, survival outcomes were similar in chemotherapy-treated patients regardless of metastatic sites (OS, p = 0.3742; PFS, p = 0.8242). Intriguingly, the immunotherapeutic predictive significance of the metastatic-organ landscape was specifically presented in PD-L1-positive populations (PD-L1 > 1%). Among them, a paradoxical coexistence of a favorable predictive effect coupled with an unfavorable prognostic effect was observed in metastases to adrenal glands, brain, and liver (category I organs), whereas metastases to bone, pleura, pleural effusion, and mediastinum yielded consistent unfavorable predictive and prognostic effects (category II organs). METscore was capable of integrating both predictive and prognostic effects of the entire landscape and dissected OS outcome of NSCLC patients received PD-(L)1 blockade (p < 0.0001) but not chemotherapy (p = 0.0805) in the OAK training cohort. Meanwhile, general performance of METscore was first validated in FIR (p = 0.0350) and BIRCH (p < 0.0001), and then in the real-world NFyy cohort (p = 0.0181). Notably, METscore was also applicable to patients received PD-(L)1 blockade as first-line treatment both in the clinical trials (OS, p = 0.0087; PFS, p = 0.0290) and in the real-world practice (OS, p = 0.0182; PFS, p = 0.0045).

CONCLUSIONS

Organ-specific metastatic landscape served as a potential predictor of immunotherapy, and METscore might enable noninvasive forecast of PD-(L)1 blockade efficacy using baseline radiologic assessments in advanced NSCLC.

Efficacy and predictors of rechallenge with immune checkpoint inhibitors in non-small cell lung cancer

BACKGROUND

The efficacy of rechallenge with immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC) patients has not yet been fully clarified. This study aimed to identify the clinical characteristics of patients with NSCLC who benefited from rechallenge with ICIs.

METHODS

We retrospectively reviewed the clinical records of 24 patients who were diagnosed with NSCLC and rechallenged with ICIs between August 2016 and July 2021.

RESULTS

Of the 24 patients included in the study, 11 were in the responder group (45.8%) and 13 in the nonresponder group (54.2%). The number of patients who used a different ICI from that used in the initial therapy was significantly higher in the responder group than in the nonresponder group (p = 0.006). Multivariate analysis identified lung metastasis and female sex as significant independent risk factors for nonresponse to rechallenge with ICIs. Compared to the nonresponder group, the duration of treatment after rechallenge with ICIs was significantly longer in the responder group (p = 0.016), and there was a trend toward longer overall survival (p = 0.059).

CONCLUSIONS

Patients with lung cancer who were rechallenged with ICIs and without progressive disease after initial ICI therapy were able to continue ICI therapy for a longer period of time. This may be associated with longer survival. Patients with lung metastases and female patients are more likely to be nonresponsive to rechallenge with ICIs. Administration of a different type of ICI from that used in the initial ICI therapy may result in disease control.

The Liver-Immunity Nexus and Cancer Immunotherapy

The impact of liver metastases on immune checkpoint-inhibitor effectiveness in patients with solid-tumor malignancies has been the focus of several recent clinical and translational studies. We review the literature describing the immune functions of the liver and particularly the mechanistic observations in these studies. The initial clinical observation was that pembrolizumab appeared to be much less effective in melanoma and non-small cell lung cancer (NSCLC) patients with liver metastasis. Subsequently other clinical studies have extended and reported similar findings with programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) inhibitors in many cancers. Two recent translational studies in animal models have dissected the mechanism of this systemic immune suppression. In both studies CD11b⁺ suppressive macrophages generated by liver metastasis in a two-site MC38 model appear to delete CD8⁺ T cells in a FasL-dependent manner. In addition, regulatory T-cell (Treg) activation was observed and contributed to the distal immunosuppression. Finally, we discuss some of the interventions reported to address liver immune suppression, such as radiation therapy, combination checkpoint blockade, and Treg depletion.

Immune Checkpoint Inhibitor Therapy for Bone Metastases: Specific Microenvironment and Current Situation

The treatment of bone metastases is a thorny issue. Immunotherapy may be one of the few hopes for patients with unresectable bone metastases. Immune checkpoint inhibitors are the most commonly used immunotherapy drugs currently. In this review, the characteristics and interaction of bone metastases and their immune microenvironment were systematically discussed, and the relevant research progress of the immunological mechanism of tumor bone metastasis was reviewed. On this basis, we expounded the clinical application of immune checkpoint inhibitors for bone metastasis of common tumors, including non-small-cell lung cancer, renal cell carcinoma, prostate cancer, melanoma, and breast cancer. Then, the deficiencies and limitations in current researches were summarized. In-depth basic research on bone metastases and optimization of clinical treatment is needed.

Brain Metastases Status and Immunotherapy Efficacy in Advanced Lung Cancer: A Systematic Review and Meta-Analysis

Background

Brain metastases (BMs) indicate poor outcomes and are commonly excluded in immunotherapy clinical trials in advanced lung cancer; moreover, the effect of BM status on immunotherapy efficacy is inconsistent and inconclusive. Therefore, we conducted a meta-analysis to assess the influence of BM status on immunotherapy efficacy in advanced lung cancer.

Methods

Electronic databases and all major conference proceedings were searched without language restrictions according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. We extracted randomized clinical trials on lung cancer immunotherapy that had available overall survival (OS) and/or progression-free survival (PFS) data based on the BM status. All analyses were performed using random effects models.

Results

Fourteen randomized clinical trials with 9,089 patients were identified. Immunotherapy conferred a survival advantage to BM patients [OS-hazard ratio (HR), 0.72; 95% confidence interval (CI), 0.58-0.90; P = 0.004; and PFS-HR, 0.68; 95% CI, 0.52-0.87, P = 0.003]. Non-BM patients could also derive a survival benefit from immunotherapy (OS-HR, 0.76; 95% CI, 0.71-0.80; P <0.001; and PFS-HR, 0.68; 95% CI, 0.56-0.82, P <0.001). The pooled ratios of OS-HRs and PFS-HRs reported in BM patients versus non-BM patients were 0.96 (95% CI, 0.78-1.18; P = 0.72) and 0.97 (95% CI, 0.79-1.20; P = 0.78), respectively, indicating no statistically significant difference between them. Subsequent sensitivity analyses did not alter the results. Subgroup analyses according to tumor type, line of therapy, immunotherapy type, study design, and representation of BM patients reconfirmed these findings.

Conclusion

We demonstrated that BM status did not significantly influence the immunotherapy efficacy in lung cancer, suggesting that both BM and non-BM patients could obtain comparable benefits.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier (CRD42020207446).