Regulatory T cell control of systemic immunity and immunotherapy response in liver metastasis

Immunotherapy and tumor mutational burden in cancer patients with liver metastases: A meta and real word cohort analysis

Background

The predictive effects of liver metastases for immune-checkpoint inhibitors (ICIs) and the relationship between tumor mutational burden (TMB) and liver metastases (LM) remain unclear.

Methods

A systematic review and meta-analysis were conducted to explore the heterogeneity of ICIs efficacy between patients with or without LM. A pan-cancer cohort of 1,661 patients who received ICIs was downloaded and analyzed to assess the association between TMB and LM.

Results

Of 21053 studies identified in our search, eight single-arm studies and 24 randomized controlled trials were included. Overall, 17957 patients with advanced or metastatic cancers (4805 patients (26.8%) with LM and 13151 patients (73.2%) without LM) were enrolled. The pooled objective response rate (ORR) was 8.5% (95% CI 4%-13%) in the LM group versus 21% (95% CI 16%-21%) in the non-LM group. The pooled hazard ratio (HR) for death was 0.85 (95% CI 0.80-0.90) in the LM group treated with ICIs compared with the standard of care. In patients without LM who were treated with ICIs, the pooled HR for death was 0.78 (95% CI 0.73-0.82) compared with the standard of care. The difference in efficacy between patients with or without LM treated with ICIs was significant (p=0.04). Pan-cancer analysis revealed that the TMB-high rate was 10.8% in liver metastatic lesions versus 21.4% in other metastatic lesions (p=0.004). In addition, TMB was also significantly associated with OS as a binary cutoff (p=0.05) and was an independent prognostic variable (HR=0.98, P=0.047) as a continuous variable in patients with LM.

Conclusions

In patients with LM, the efficacy of immunotherapy was attenuated, but TMB-high could predict better survival outcomes.

Leptin's Immune Action: A Review Beyond Satiety

The adipose tissue is an endocrine organ that secretes adipokines such as leptin, which is one of the most important hormones for controlling satiety, metabolism, and energy homeostasis. This hormone acts in the regulation of innate and adaptive immune responses since immune cells have leptin receptors from which this hormone initiates its biological action. These receptors have been identified in hematopoietic stem cells in the bone marrow and mature immune cells, inducing signaling pathways mediated by JAK/STAT, PI3K, and ERK 1/2. It is known that the bone marrow also contains leptin-producing adipocytes, which are crucial for regulating hematopoiesis through largely unknown mechanisms. Therefore, we have reviewed the roles of leptin inside and outside the bone marrow, going beyond its action in the control of satiety.

Type I and II interferon signaling in colorectal cancer liver metastasis

Metastatic colorectal cancer is one of the leading causes of cancer-related deaths worldwide. Traditional chemotherapy extended the lifespan of cancer patients by only a few months, but targeted therapies and immunotherapy prolonged survival and led to long-term remissions in some cases. Type I and II interferons have direct pro-apoptotic and anti-proliferative effects on cancer cells and stimulate anti-cancer immunity. As a result, interferon production by cells in the tumor microenvironment is in the spotlight of immunotherapies as it affects the responses of anti-cancer immune cells. However, promoting effects of interferons on colorectal cancer metastasis have also been reported. Here we summarize our knowledge about pro- and anti-metastatic effects of type I and II interferons in colorectal cancer liver metastasis and discuss possible therapeutic implications.

Serum CCL22 Increased in Advanced Melanoma Patients with Liver Metastases: Report of 5 Cases

Advanced melanoma patients with liver metastases show a limited response to immunotherapy by the induction of regulatory T cells and depletion of effector cells, which leads to a poor prognosis. Tumor-associated macrophages (TAMs) induce apoptosis of activated antigen-specific CD8+ T cells in melanomas, leading to induction of tolerance to immune checkpoint inhibitors. In addition, TAMs produce various chemokines, and several serum pro-inflammatory chemokines measured at baseline are useful for the prediction of the efficacy of immunomodulatory drugs. In this study, serum levels of CCL22, CXCL5, and CXCL10 were evaluated by ELISA at baseline in 10 melanoma patients, 5 with liver metastases and 5 with lung metastases, treated with anti-PD1 Abs. Serum levels of CCL22, but not CXCL5 and CXCL10, were increased in patients with liver metastases compared to those with lung metastases or historical controls. The present data suggest that elevated serum CCL22 levels might be a biomarker for liver metastases in melanoma patients.

High serum LDH and liver metastases are the dominant predictors of primary cancer resistance to anti-PD(L)1 immunotherapy

AIM

Anti-PD-(L)1 immunotherapies improve survival in multiple cancers but remain ineffective for most patients. We applied machine-learning algorithms and multivariate analyses on baseline medical data to estimate their relative impact on overall survival (OS) upon anti-PD-(L)1 monotherapies.

METHOD

This prognostic/predictive study retrospectively analysed 33 baseline routine medical variables derived from computed tomography (CT) images, clinical and biological meta-data. 695 patients with a diagnosis of advanced cancer were treated in prospective clinical trials in a single tertiary cancer centre in 3 cohorts including systemic anti-PD-(L)1 (251, 235 patients) versus other systemic therapies (209 patients). A random forest model combined variables to identify the combination (signature) which best estimated OS in patients treated with immunotherapy. The performance for estimating OS [95%CI] was measured using Kaplan-Meier Analysis and Log-Rank test.

RESULTS

Elevated serum lactate dehydrogenase (LDHhi) and presence of liver metastases (LM+) were dominant and independent predictors of short OS in independent cohorts of melanoma and non-melanoma solid tumours. Overall, LDHhiLM+ patients treated with anti-PD-(L)1 monotherapy had a poorer outcome (median OS: 3.1[2.4-7.8] months]) compared to LDHlowLM-patients (median OS: 15.3[8.9-NA] months; P < 0.0001). The OS of LDHlowLM-patients treated with immunotherapy was 28.8[17.9-NA] months (vs 13.1[10.8-18.5], P = 0.02) in the overall population and 30.3[19.93-NA] months (vs 14.1[8.69-NA], P = 0.0013) in patients with melanoma.

CONCLUSION

LDHhiLM+ status identifies patients who shall not benefit from anti-PD-(L)1 monotherapy. It could be used in clinical trials to stratify patients and eventually address this specific medical need.

Near complete response to a pembrolizumab-based therapeutic strategy in an abdominal metastatic head and neck squamous cell carcinoma case

Metastasis of head and neck squamous cell carcinoma rarely occurs in hepatic cancer and has a poor prognosis (median survival of 4 months). The efficacy of immunotherapy for these patients remains unknown. Herein, we present a patient with hypopharyngeal carcinoma metastasis to the liver with TERT and TP53 mutations together with a combined positive score of 70. The tumor invaded the abdominal wall, liver, inferior vena cava and retroperitoneal lymph nodes. The patient was treated with pembrolizumab combined with cisplatin and 5-FU for four cycles and has been maintained on pembrolizumab monotherapy until now. The patient achieved a near complete response of hepatic and subcutaneous metastases, and the tumor thrombus disappeared completely. The patient developed grade I rashes on the trunk, which were considered immune-related adverse events; thus, the patient presented a significant tumor response and good tolerance to the therapeutic strategy. On the basis of this observation, pembrolizumab-based therapeutic strategies may be an effective alternative for metastatic hypopharyngeal carcinoma and may prolong overall survival and progression-free survival, which should be confirmed by more patients in the future. Immune-related adverse events also need attention.

The effect of organ-specific tumor microenvironments on response patterns to immunotherapy

Immunotherapy, particularly immune checkpoint inhibitors, have become widely used in various settings across many different cancer types in recent years. Whilst patients are often treated on the basis of the primary cancer type and clinical stage, recent studies have highlighted disparity in response to immune checkpoint inhibitors at different sites of metastasis, and their impact on overall response and survival. Studies exploring the tumor immune microenvironment at different organ sites have provided insights into the immune-related mechanisms behind organ-specific patterns of response to immunotherapy. In this review, we aimed to highlight the key learnings from clinical studies across various cancers including melanoma, lung cancer, renal cell carcinoma, colorectal cancer, breast cancer and others, assessing the association of site of metastasis and response to immune checkpoint inhibitors. We also summarize the key clinical and pre-clinical findings from studies exploring the immune microenvironment of specific sites of metastasis. Ultimately, further characterization of the tumor immune microenvironment at different metastatic sites, and understanding the biological drivers of these differences, may identify organ-specific mechanisms of resistance, which will lead to more personalized treatment approaches for patients with innate or acquired resistance to immunotherapy.

Liver metastases and the efficacy of immune checkpoint inhibitors in advanced lung cancer: A systematic review and meta-analysis

Background

Liver metastasis is the most common type of lung cancer metastasis, and is a significant prognostic factor in lung cancer. However, the effect of liver metastases on the efficacy of immune checkpoint inhibitors (ICIs) remains inconsistent and controversial. The aim of this study was to explore the relationship between liver metastases and ICI efficacy in patients with advanced lung cancer based on data from randomized controlled trials (RCTs) and observational studies.

Methods

PubMed, EMBASE, Cochrane Library databases, conference proceedings, as well as grey literature websites were searched for eligible studies without language restrict ion. Study quality was assessed using Cochrane tools and the Newcastle–Ottawa Quality Assessment Scale (NOS). Outcomes of interest were overall survival (OS) and progression-free survival (PFS). The difference in efficacy between patients with and without liver metastases was calculated by pooling ratios of hazard ratios (HR), as calculated using the deft approach.

Results

A total of 16 RCTs and 14 observational trials were included. Analyses of RCTs revealed a survival benefit for ICI treatment (i.e., ICI monotherapy, ICI + Chemotherapy, dual ICI therapy and dual ICI + Chemotherapy) versus standard therapies among non-small cell lung cancer (NSCLC) patients with liver metastases (PFS HR, 0.77; 95%CI, 0.61–0.97; OS HR, 0.78; 95%CI, 0.68–0.90). NSCLC patients with liver metastases achieved less PFS benefit and comparable OS benefit from ICI treatment compared with those without liver metastases (ratios of PFS–HRs, 1.19; 95%CI, 1.02–1.39; P=0.029; Ratios of OS–HRs, 1.10; 95%CI, 0.94–1.29; P=0.24). For patients with small cell lung cancer (SCLC), ICI treatment achieved a marginal effect on patients with liver metastases as compared with standard therapies (OS HR, 0.94; 95%CI, 0.73–1.23). SCLC patients with liver metastases benefited less from ICI treatment than patients without liver metastases (ratio of OS–HRs, 1.22; 95%CI, 1.01–1.46; P=0.036). In real-world data analysis, liver metastasis could be used as an independent prognostic risk factor, increasing the risk of death by 21% in lung cancer patients receiving ICI treatment compared with those without liver metastases (OS HR, 1.21; 95%CI, 1.17–1.27; P<0.0001). Subgroup analysis confirmed that this association was not modified by race (Asian vs. Western) or number of treatment lines.

Conclusions

The presence of liver metastases does not significantly influence the OS benefit of ICIs in patients with NSCLC. However, a small amount of data shows that liver metastasis restrains the magnitude of OS benefit in patients with SCLC. Liver metastasis has potential as an independent prognostic risk factor for lung cancer patients receiving ICI treatment in clinical practice.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022306449).

Prognostic characteristics and clinical response to immunotherapy targeting programmed cell death 1 for patients with advanced gastric cancer with liver metastases

Background

The specific efficacy of immunotherapy for patients with liver metastases of gastric cancer is unclear. This study set out to explore the treatment response and related prognostic factors for patients with liver metastases of gastric cancer treated with immunotherapy.

Patients and methods

This retrospective cohort study included 135 patients with unresectable advanced gastric cancer. According to the presence of liver metastases and/or first-line treatment with immunotherapy, patients were divided into the following three groups: I-LM(-) group(patients without liver metastases treated with immunotherapy, n=66), I-LM(+) group(patients with liver metastases treated with immunotherapy, n=36), C-LM(+) group(patients with liver metastases treated with chemotherapy and/or target therapy, n=33). Cox regression analyses were used to identify factors associated with survival in all patients and the three groups, respectively.

Results

For the patients with liver metastases treated with immunotherapy, multivariate analysis showed that only the presence of peritoneal metastases was significantly associated with shorter PFS [hazard ratios (HR), 3.23; 95% CI, 1.12-9.32; P=0.030] and the patients with peritoneal metastases had shorter median PFS than patients without peritoneal metastases(3.1 vs 18.4 months; P=0.004), while the objective response rate was 100% in patients with HER2-positive (2 complete radiographic responses and 2 partial responses; 3 of 4 patients were still ongoing benefits [median follow-up time, 15.3 months ; interquartile range(IQR), 6.3-17.9 months]).

Conclusions

The findings suggest that patients with various types of gastric cancer liver metastases respond differently to immune checkpoint inhibitors, HER2-positive patients may derive clinical benefits from immune checkpoint inhibitors, while the presence of peritoneal metastases is associated with resistance.

The Efficacy of PD-1/PD-L1 Inhibitors in Patients with Liver Metastasis of Non-Small Cell Lung Cancer: A Real-World Study

BACKGROUND

A controversy exists regarding the efficacy of programmed death-1 (PD-1)/ programmed death ligand-1 (PD-L1) inhibitors for patients with non-small cell lung cancer (NSCLC) and liver metastases. Our study retrospectively evaluated the efficacy of PD-1/PD-L1 inhibitors in NSCLC patients with liver metastases.

METHODS

This retrospective study included 1627 lung cancer patients who received immunotherapy. Among 648 patients who had advanced NSCLC and received PD-1/PD-L1 inhibitors, 61 had liver metastases and 587 did not have. We analyzed patient characteristics, progression-free survival (PFS) and overall survival (OS). An exploratory analysis of biomarkers including CD4, CD8 and CD68 for efficacy in patients with liver metastases was also performed.

RESULTS

In liver metastasis patients receiving PD-1/PD-L1 inhibitors, the objective response rate (ORR) was 29.5%, the disease control rate (DCR) was 72.1%, PFS was 6.4 months and OS was 15.2 months, which were all worse than those of patients without liver metastases (ORR: 35.8%; DCR: 81.8%; PFS: 7.9 months, p = 0.001; OS: 20.6 months, p = 0.008). When compared to non-liver lesions, the ORR (26.2 vs. 39.3%) and DCR (75.4 vs. 88.5%) of liver lesions were lower. During the analysis of PD-L1 expression, 27 PD-L1-positive patients had a longer PFS than 21 patients in the negative group (p = 0.012). Being PD-L1 positive was the independent prognostic indicators for PFS (p = 0.006). Additionally, the PD-L1 and CD8 dual-positive group responded favorably to PD-1/PD-L1 inhibitors.

CONCLUSIONS

PD-1/PD-L1 inhibitors are effective in liver metastasis-NSCLC patients. However, the efficacy is inferior when compared to those of patients without liver metastases. In NSCLC patients with liver metastases, PD-L1 expression and CD8+ T cell infiltration can predict the response of PD-1/PD-L1-directed immunotherapy.

Updated Efficacy Outcomes of Anti-PD-1 Antibodies plus Multikinase Inhibitors for Patients with Advanced Gastric Cancer with or without Liver Metastases in Clinical Trials

PURPOSE

We previously reported preliminary activity of regorafenib plus nivolumab (REGONIVO) or lenvatinib plus pembrolizumab (LENPEM) in advanced gastric cancer (AGC). Meanwhile, several studies demonstrated liver metastases are less responsive to immunotherapy.

PATIENTS AND METHODS

Combined efficacy outcomes with a longer follow-up in a phase Ib trial of REGONIVO and a phase II trial of LENPEM were examined in AGC with or without liver metastases (REGONIVO plus LENPEM cohort). We also investigated the efficacy of anti-PD-1 monotherapies (anti-PD-1 monotherapy cohort). A comparison of the immune microenvironment between gastric primary tumors and liver metastases was also conducted by multiplex IHC.

RESULTS

In the REGONIVO plus LENPEM cohort, with a median follow-up of 14.0 months, objective response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) were 46%, 7.8 months, and 15.6 months in patients with liver metastases, while 69%, 6.9 months, and 15.5 months in those without. In the anti-PD-1 monotherapy cohort, with a median follow-up of 27.6 months, ORR, mPFS, and mOS were 9%, 1.4 months, and 6.4 months in patients with liver metastases, while 22%, 2.3 months, and 9.0 months in those without. Multiplex IHC revealed liver metastases were associated with an abundance of immune-suppressive cells, such as tumor-associated macrophages and regulatory T cells, with fewer CD8+ T cells compared with gastric primary tumors.

CONCLUSIONS

Anti-PD-1 antibodies plus regorafenib or lenvatinib for AGC showed promising antitumor activity with a longer follow-up, irrespective of liver metastases status, despite a more immune-suppressive tumor microenvironment in liver metastases.

Emerging role of EZH2 in rheumatic diseases: A comprehensive review

Enhancer of zeste homolog 2 (EZH2) is a histone methylated enzyme. It trimethylates histone 3 lysine 27 (H3K27) to regulate epigenetic processes. Recently, studies showed excessive expression of EZH2 in rheumatic diseases, such as systemic lupus erythematosus, rheumatoid arthritis, osteoarthritis, and systemic sclerosis. Moreover, epigenetic modification of EZH2 regulates differentiation and proliferation of different immune cells. Therefore, in this review, we comprehensively discuss the role of EZH2 in rheumatic diseases. Collection of the evidence may provide a basis for further understanding the role of EZH2 and give potential for targeting these diseases.

Early mortality factors in immune checkpoint inhibitor monotherapy for advanced or metastatic non-small cell lung cancer

Purpose

Immune checkpoint inhibitors (ICI) are a promising treatment, but may cause hyperprogressive disease and early death. The present study investigated early mortality factors in ICI monotherapy for lung cancer.

Patients and methods

We retrospectively reviewed all patients diagnosed with advanced or metastatic non-small cell lung cancer (NSCLC) and treated with ICI monotherapy (nivolumab, pembrolizumab, and atezolizumab) between March 2016 and August 2021 at National Hospital Organization Kochi Hospital and Tokushima University. Early death was defined as patients who died within 60 days of ICI treatment.

Results

A total of 166 patients were included. The majority of patients (87%) had an Eastern cooperative oncology group (ECOG) Performance status (PS) of 0/1. There were 21 early deaths. Significant differences were observed in ECOG PS, the histological type, liver metastasis, tumor size, the white blood cell count, neutrophils (%), lymphocytes (%), the neutrophil-to-lymphocyte ratio in serum (sNLR), C-reactive protein (CRP), and albumin between the groups with or without early death. Univariate logistic regression analyses identified ECOG PS score ≥ 2, liver metastasis, tumor size ≥ 5 cm, neutrophils ≥ 69%, lymphocytes < 22%, sNLR ≥ 4, CRP ≥ 1 mg/dl, and albumin < 3.58 g/dl as significant risk factors for early death. A multivariate logistic regression analysis revealed that liver metastasis (Odds ratio [OR], 10.3; p = 0.008), ECOG PS score ≥ 2 (OR, 8.0; p = 0.007), and a smoking history (OR, 0.1; p = 0.03) were significant risk factors for early death.

Conclusion

Liver metastases, ECOG PS score ≥ 2, and a non-smoking history are early mortality factors in ICI monotherapy for advanced or metastatic NSCLC.

Using machine learning for mortality prediction and risk stratification in atezolizumab-treated cancer patients: Integrative analysis of eight clinical trials

BACKGROUND

Few models exist to predict mortality in cancer patients receiving immunotherapy. Our aim was to build a machine learning-based risk stratification model for predicting mortality in atezolizumab-treated cancer patients.

METHODS

Data from 2538 patients in eight atezolizumab-treated cancer clinical trials across three cancer types (non-small-cell lung cancer, bladder transitional cell carcinoma, and renal cell carcinoma) were included. The whole cohort was randomly split into development and validation cohorts in a 7:3 ratio. Machine-learning algorithms (extreme gradient boosting, random forest, logistic regression with lasso regularization, support vector machine, and K-nearest neighbor) were applied to develop prediction models. Model performance was mainly assessed by area under the receiver operating characteristic curve (AUC) value, calibration plot, and decision curve analysis. The probability of death risk was then stratified.

RESULTS

One thousand and three hundred and seventy-nine (54.33%) patients died. The random forest (RF) model was overall the best in terms of predictive performance, with the AUC of 0.844 (95% confidence interval [CI]: 0.826-0.862) in the development cohort and 0.786 (95% CI: 0.754-0.818) in the validation cohort for predicting mortality. Twelve baseline variables contributing to mortality prediction in the RF model were C-reactive protein, PD-L1 level, cancer type, prior liver metastasis, derived neutrophil-to-lymphocyte ratio, alkaline phosphatase, albumin, hemoglobin, white blood cell count, number of metastatic sites, pulse rate, and Eastern Cooperative Oncology Group (ECOG) performance status. A total of 1782 (70.2%) patients were separated into the high-risk and 756 (29.8%) low-risk groups. Patients in the high-risk group were significantly more likely to die, experience disease progression, discontinue study, and discontinue treatment than patients in the low-risk group (all p values < 0.001). Risk groups were not associated with immune-related adverse events and grades 3-5 treatment-related adverse events (all p values > 0.05).

CONCLUSION

RF model has good performance in mortality prediction and risk stratification for cancer patients receiving atezolizumab monotherapy.

The presence and size of intrahepatic tumors determine the therapeutic efficacy of nivolumab in advanced hepatocellular carcinoma

Purpose:

Inter-tumoral heterogeneity at the differential lesion level raises the possibility of distinct organ-specific responses to immune checkpoint inhibitors (ICIs). We aimed to comprehensively examine the clinicopathological factors to predict and assess the efficacy of nivolumab, programmed cell death protein 1 (PD-1) blockade at an individual tumor site-specific level in patients with advanced hepatocellular carcinoma (aHCC).

Patients and Methods:

We enrolled 261 aHCC patients treated with nivolumab between 2012 and 2018. Eighty-one clinicopathological factors were comprehensively collected and analyzed. The association between all variables and survival outcomes was evaluated. According to tumor site, the organ-specific responses were assessed based on the Response Evaluation Criteria in Solid Tumors, version 1.1.

Results:

The liver was the most commonly involved organ (75.1%), followed by the lungs (37.5%) and lymph nodes (LNs, 11.5%). The liver of nonresponders was more frequently the organ of progression, while the lungs of responders were more frequently the organs of response. Among the 455 individual lesions (liver, n = 248; lung, n = 124; LN, n = 35; others including bone or soft tissues, n = 48), intrahepatic tumors showed the least response (10.1%), followed by lung (24.2%) and LN tumors (37.1%), indicating the presence of distinct organ-specific responses to nivolumab. In intrahepatic tumors, the organ-specific response rate decreased as the size increased (13% for ⩽50 mm, 8.1% for 50–100 mm, and 5.5% for >100 mm). In the subgroup analysis according to tumor location, patients with lung only metastasis (⩾30 mm) showed the best progression-free survival (PFS) and overall survival (OS). In contrast, primary HCC (⩾100 mm) without lung metastasis had the worst PFS and OS. Comprehensive analyses also revealed that liver function and systemic inflammatory indices, such as neutrophil-to-lymphocyte ratio (NLR), were significantly associated with PFS and OS.

Conclusion:

The presence and size of liver tumors, liver function, and NLR are key factors determining the response to nivolumab in aHCC. These clinical factors should be considered when treating patients with advanced HCC with PD-1 blockade.

Regulatory T cells and their associated factors in hepatocellular carcinoma development and therapy

Liver cancer is the third leading cause of cancer-related death worldwide with primary type hepatocellular carcinoma (HCC). Factors, including carcinogens, infection of hepatitis viruses, alcohol abuse, and non-alcoholic fatty liver disease (NAFLD), can induce HCC initiation and promote HCC progression. The prevalence of NAFLD accompanying the increased incidence of obesity and type 2 diabetes becomes the most increasing factor causing HCC worldwide. However, the benefit of current therapeutic options is still limited. Intrahepatic immunity plays critically important roles in HCC initiation, development, and progression. Regulatory T cells (Tregs) and their associated factors such as metabolites and secreting cytokines mediate the immune tolerance of the tumor microenvironment in HCC. Therefore, targeting Tregs and blocking their mediated factors may prevent HCC progression. This review summarizes the functions of Tregs in HCC-inducing factors including alcoholic and NAFLD, liver fibrosis, cirrhosis, and viral infections. Overall, a better understanding of the role of Tregs in the development and progression of HCC provides treatment strategies for liver cancer treatment.

Can Radiotherapy Empower the Host Immune System to Counterattack Neoplastic Cells? A Systematic Review on Tumor Microenvironment Radiomodulation

Despite the rising evidence in favor of immunotherapy (IT), the treatment of oncological patients affected by so-called "cold tumors" still represents an open issue. Cold tumors are characterized by an immunosuppressive (so-called cold) tumor microenvironment (TME), which favors host immune system suppression, cancer immune-escape, and a worse response to IT. However, the TME is not a static element, but dynamically mutates and can be changed. Radiotherapy (RT) can modulate a cold microenvironment, rendering it better at tumor killing by priming the quiescent host immune system, with a consequent increase in immunotherapy response. The combination of TME radiomodulation and IT could therefore be a strategy for those patients affected by cold tumors, with limited or no response to IT. Thus, this review aims to provide an easy, rapid, and practical overview of how RT could convert the cold TME and why cold tumor radiomodulation could represent an interesting strategy in combination with IT.

Blood Stasis Syndrome Accelerates the Growth and Metastasis of Breast Cancer by Promoting Hypoxia and Immunosuppressive Microenvironment in Mice

Blood stasis syndromes (BSSs) are closely related to the occurrence and development of tumors, although the mechanism is still unclear. This study was aimed at exploring the effect and mechanism underlying different BSSs on tumor growth and metastasis. We established four BSS mouse models bred with breast cancer: qi deficiency and blood stasis (QDBS), cold coagulation blood stasis (CCBS), heat toxin and blood stasis (HTBS), and qi stagnation and blood stasis (QSBS). The results showed that microcirculation in the lower limb, abdominal wall, and tumor in situ decreased by varying degrees in the BSS groups. In addition, BSS promoted tumor growth and lung metastasis. The ratio of regulatory T cells in the tumor microenvironment was downregulated. Moreover, hypoxia-inducible factor 1-α, Wnt1, β-catenin, vascular endothelial growth factor, and Cyclin D1 levels increased in the tumors of BSS mice. In conclusion, BSS not only promoted the formation of a hypoxic and immunosuppressive microenvironment but also promoted the neovascularization.

Immunosuppressive cells in cancer: mechanisms and potential therapeutic targets

Immunotherapies like the adoptive transfer of gene-engineered T cells and immune checkpoint inhibitors are novel therapeutic modalities for advanced cancers. However, some patients are refractory or resistant to these therapies, and the mechanisms underlying tumor immune resistance have not been fully elucidated. Immunosuppressive cells such as myeloid-derived suppressive cells, tumor-associated macrophages, tumor-associated neutrophils, regulatory T cells (Tregs), and tumor-associated dendritic cells are critical factors correlated with immune resistance. In addition, cytokines and factors secreted by tumor cells or these immunosuppressive cells also mediate the tumor progression and immune escape of cancers. Thus, targeting these immunosuppressive cells and the related signals is the promising therapy to improve the efficacy of immunotherapies and reverse the immune resistance. However, even with certain success in preclinical studies or in some specific types of cancer, large perspectives are unknown for these immunosuppressive cells, and the related therapies have undesirable outcomes for clinical patients. In this review, we comprehensively summarized the phenotype, function, and potential therapeutic targets of these immunosuppressive cells in the tumor microenvironment.

Biomarkers of Response and Resistance to Immunotherapy in Microsatellite Stable Colorectal Cancer: Toward a New Personalized Medicine

Immune Checkpoint Inhibitors (ICIs) are well recognized as a major immune treatment modality for multiple types of solid cancers. However, for colorectal cancer (CRC), ICIs are only approved for the treatment of Mismatch-Repair-Deficient and Microsatellite Instability-High (dMMR/MSI-H) tumors. For the vast majority of CRC, that are not dMMR/MSI-H, ICIs alone provide limited to no clinical benefit. This discrepancy of response between CRC and other solid cancers suggests that CRC may be inherently resistant to ICIs alone. In translational research, efforts are underway to thoroughly characterize the immune microenvironment of CRC to better understand the mechanisms behind this resistance and to find new biomarkers of response. In the clinic, trials are being set up to study biomarkers along with treatments targeting newly discovered immune checkpoint molecules or treatments combining ICIs with other existing therapies to improve response in MSS CRC. In this review, we will focus on the characteristics of response and resistance to ICIs in CRC, and discuss promising biomarkers studied in recent clinical trials combining ICIs with other therapies.

Visual Analysis of Colorectal Cancer Immunotherapy: A Bibliometric Analysis From 2012 to 2021

An increasing number of studies have shown that immunotherapy serves a significant role in treating colorectal cancer (CRC) and has become a hotspot. However, few studies used the bibliometric method to analyze this field comprehensively. This study collected 1,899 records of CRC immunotherapy from 2012 to October 31, 2021, and used CiteSpace to analyze regions, institutions, journals, authors, and keywords to predict the latest trends in CRC immunotherapy research. The United States and China, contributing more than 60% of publications, were the main drivers in this field. Sun Yat-sen University was the most active institution, while the National Cancer Institute had the highest frequency of citations. Most publications were published in the Journal for Immunotherapy of Cancer. Adam E Snook was the most prolific writer, while Dung T. Le was the most commonly co-cited author. “T cell”, “MMI” and “PD-1blocked” were the most widely studied aspects of CRC immunotherapy. “Immune checkpoint inhibitor”, “combination therapy”, “drug therapy” and “liver metastases” were current research hotspots. “Tumor microenvironment”, “neutrophils”, “tumor-associated macrophages”, and “suppressor cell” have emerged as research hotspots in recent years. “Gut microbiota”, “nanoparticle” and “tumor mutational burden” as recently emerged frontiers of research that should be closely monitored.

Regorafenib combined with programmed cell death-1 inhibitor against refractory colorectal cancer and the platelet-to-lymphocyte ratio’s prediction on effectiveness

BACKGROUND

The effectiveness of regorafenib plus programmed cell death-1 (PD-1) inhibitor in treating microsatellite stable (MSS) metastatic colorectal cancer (mCRC) remains controversial.

AIM

To investigate the benefits of regorafenib combined with PD-1 inhibitor in treating MSS mCRC and explore indicators predicting response.

METHODS

This retrospective study included a total of 30 patients with microsatellite stable metastatic colorectal cancer treated with regorafenib combined with programmed cell death-1 inhibitor at Henan Provincial People’s Hospital between December 2018 and December 2020. During a 4-wk treatment cycle, regorafenib was performed for 3 continuous weeks. PD-1 inhibitor was intravenously injected starting on the first day of the oral intake of regorafenib. We reviewed tumor response, progression-free survival (PFS), overall survival, and treatment-related adverse events (TRAEs) and evaluated association between platelet-to-lymphocyte ratio (PLR) and outcomes in this retrospective study.

RESULTS

Stable disease and progressive disease were found in 18 (60.0%) and 12 (40.0%) patients, respectively. The disease control rate was 60.0%. The median follow-up time was 12.0 mo, and median PFS was 3.4 mo [95% confidence interval (CI): 2.2-4.6 mo]. Of the 12 patients with progressive disease, 10 (83.3%) had liver metastasis before starting the combined treatment. Among the 18 patients with SD, 10 (55.6%) did not have liver metastases. One patient without liver metastases at baseline was found with a substantially prolonged PFS of 11.2 mo. The liver metastasis, the choice of programmed cell death-1 inhibitor other than nivolumab or pembrolizumab and previous exposure to regorafenib was’t associated with treatment outcome. The median PFS in the low-PLR group was 4.2 mo (95%CI: 3.5-4.9 mo), compared with 2.8 mo (95%CI: 1.4-4.2 mo) in the high-PLR group (P = 0.005). The major TRAEs included hand-foot syndrome (33.3%), hypertension (23.3%), malaise (20.0%), and gastrointestinal reaction (16.7%). The incidence of grade 3 TRAEs was 13.3% (4/30), which comprised abnormal capillary proliferation (n = 1), transaminase elevation (n = 1), and hand-foot syndrome (n = 2). No grade 4 or higher toxicity was observed.

CONCLUSION

Regorafenib combined with PD-1 inhibitor could lead to a longer PFS in some patients with MSS mCRC. The PLR might be a prediction of the patient response to this therapy.

Fusobacterium nucleatum promotes liver metastasis in colorectal cancer by regulating the hepatic immune niche and altering gut microbiota

Liver metastasis is the major cause of death in colorectal cancer (CRC) patients. Nevertheless, the underlying mechanisms remain unknown. Gut microbiota intricately affect the initiation and progression of CRC by instigating immune response through the secretion of pro-inflammatory cytokines. In this study, we investigated the contribution of Fusobacterium nucleatum (F.nucleatum) to the microbiota-liver axis of CRC in mice, focusing on the correlation between liver immunity and gut microbiota alterations. When F. nucleatum was orally administered to mice, CRC liver metastasis was evidently exaggerated and accompanied by noticeable deleterious effects on body weight, cecum weight, and overall survival time. Further evaluation of the immune response and cytokine profiles revealed a substantial increase in the levels of pro-inflammatory cytokines such as IL6, IL12, IL9, IL17A, CXCL1, MCP-1, TNF-α, and IFN-γ in the plasma of mice treated with F. nucleatum as compared to that in the untreated control mice. Besides, hepatic immune response was also modulated by recruitment of myeloid-derived suppressor cells, reduction in the infiltration of natural killer (NK) and T helper-17 (Th17) cells, as well as increase in regulatory T cell accumulation in the liver. Additionally, sustained F. nucleatum exposure abridged the murine gut microbiota diversity, inducing an imbalanced and restructured intestinal microflora. In particular, the abundance of CRC-promoting bacteria such as Enterococcus and Escherichia/Shigella was evidently elevated post F. nucleatum treatment. Thus, our findings suggest that F. nucleatum might be an important factor involved in promoting CRC liver metastasis by triggering of liver immunity through the regulation of gut microbiota structure and composition.

Lactic acid promotes PD-1 expression in regulatory T cells in highly glycolytic tumor microenvironments

The balance of programmed death-1 (PD-1)-expressing CD8⁺ T cells and regulatory T (Treg) cells in the tumor microenvironment (TME) determines the clinical efficacy of PD-1 blockade therapy through the competition of their reactivation. However, factors that determine this balance remain unknown. Here, we show that Treg cells gain higher PD-1 expression than effector T cells in highly glycolytic tumors, including MYC-amplified tumors and liver tumors. Under low-glucose environments via glucose consumption by tumor cells, Treg cells actively absorbed lactic acid (LA) through monocarboxylate transporter 1 (MCT1), promoting NFAT1 translocation into the nucleus, thereby enhancing the expression of PD-1, whereas PD-1 expression by effector T cells was dampened. PD-1 blockade invigorated the PD-1-expressing Treg cells, resulting in treatment failure. We propose that LA in the highly glycolytic TME is an active checkpoint for the function of Treg cells in the TME via upregulation of PD-1 expression.

Angiogenic and molecular diversity determine hepatic melanoma metastasis and response to anti-angiogenic treatment

BACKGROUND

Cutaneous melanoma exhibits heterogeneous metastatic patterns and prognosis. In this regard, liver metastasis, which is detected in ~ 10-20% of stage 4 patients, came to the fore of melanoma research, as it recently evolved as decisive indicator of treatment resistance to immune checkpoint inhibition.

METHODS

Hepatic metastases were induced by intrasplenic injection of five different murine melanoma cell lines. The efficiencies of hepatic colonization, morphologic patterns, gene expression profiles and degree of vascularization were analyzed and Sorafenib was applied as anti-angiogenic treatment.

RESULTS

WT31 melanoma showed the highest efficiency of hepatic colonization, while intermediate efficiencies were observed for B16F10 and RET, and low efficiencies for D4M and HCmel12. RNAseq-based gene expression profiles of high and intermediate metastatic melanomas in comparison to low metastatic melanomas indicated that this efficiency predominantly associates with gene clusters involved in cell migration and angiogenesis. Indeed, heterogeneous vascularization patterns were found in the five models. Although the degree of vascularization of WT31 and B16F10 metastases differed, both showed a strong response to Sorafenib with a successful abrogation of the vascularization.

CONCLUSION

Our data indicate that molecular heterogeneity of melanomas can be associated with phenotypic and prognostic features of hepatic metastasis paving the way for organ-specific anti-angiogenic therapeutic approaches.

The prognosis of HPV-associated metastatic pharyngeal patients by primary and distant site

OBJECTIVES

Human papillomavirus (HPV) positivity is a favorable prognostic factor in the general population of head and neck squamous cell carcinoma (HNSCC) patients. However, its impact on the survival of metastatic HNSCC of pharynx (mHNSC-P) patients is unclear. This study aims to investigate the associations between HPV status and survival in mHNSC-P patients.

METHODS

735 mHNSC-P patients diagnosed at first presentation from 2010 to 2016 were retrieved from the Surveillance, Epidemiology and End Result database (SEER). Chi-Squared test, univariate and multivariate cox proportional hazards model, Kaplan-Meier analysis, and log-rank test were applied to compare HPV-positive and -negative mHNSC-P patients.

RESULT

Using univariate cox proportional hazards analysis, HPV status, primary site, T stage, treatment and distant metastatic site correlate with the overall survival (OS) and disease-specific survival (DSS) in mHNSC-P patients. Multivariate cox regression analysis shows that HPV-positive mHNSC-P patients experienced significantly better OS (HR: 0.62 CI: 0.51-0.76, p < 0.001) and DSS (HR: 0.73 CI: 0.58-0.91, p < 0.01) as compared to HPV-negative mHNSC-P patients. Subgroup analysis indicates that HPV-associated OS and DSS benefits exist in patients with metastatic HNSCC of oropharynx (mHNSC-OP) but not in patients with metastatic HNSCC of non-oropharynx (mHNSC-non-OP). Among mHNSC-OP patients, HPV positivity confers disease-specific survival benefit in patients with oligometastatic rather than polymetastatic patients. Furthermore, HPV associated OS and DSS advantages in mHNSC-OP with lung metastasis was observed.

CONCLUSION

HPV-positive mHNSC-OP patients with lung metastasis show better survival than HPV-negative mHNSC-OP patients, providing key information to guide patient treatment approaches.

Factors Determining Long-Term Antitumor Responses to Immune Checkpoint Blockade Therapy in Melanoma

With the increasing promise of long-term survival with immune checkpoint blockade (ICB) therapies, particularly for patients with advanced melanoma, clinicians and investigators are driven to identify prognostic and predictive factors that may help to identify individuals who are likely to experience durable benefit. Several ICB combinations are being actively developed to expand the armamentarium of treatments for patients who may not achieve long-term responses to ICB single therapies alone. Thus, negative predictive markers are also of great interest. This review seeks to deepen our understanding of the mechanisms underlying the durability of ICB treatments. We will discuss the currently available long-term data from the ICB clinical trials and real-world studies describing the survivorship of ICB-treated melanoma patients. Additionally, we explore the current treatment outcomes in patients rechallenged with ICB and the patterns of ICB resistance based on sites of disease, namely, liver or CNS metastases. Lastly, we discuss the landscape in melanoma in the context of prognostic or predictive factors as markers of long-term response to ICB.

Tissue-specific Tregs in cancer metastasis: opportunities for precision immunotherapy

Decades of advancements in immuno-oncology have enabled the development of current immunotherapies, which provide long-term treatment responses in certain metastatic cancer patients. However, cures remain infrequent, and most patients ultimately succumb to treatment-refractory metastatic disease. Recent insights suggest that tumors at certain organ sites exhibit distinctive response patterns to immunotherapy and can even reduce antitumor immunity within anatomically distant tumors, suggesting the activation of tissue-specific immune tolerogenic mechanisms in some cases of therapy resistance. Specialized immune cells known as regulatory T cells (Tregs) are present within all tissues in the body and coordinate the suppression of excessive immune activation to curb autoimmunity and maintain immune homeostasis. Despite the high volume of research on Tregs, the findings have failed to reconcile tissue-specific Treg functions in organs, such as tolerance, tissue repair, and regeneration, with their suppression of local and systemic tumor immunity in the context of immunotherapy resistance. To improve the understanding of how the tissue-specific functions of Tregs impact cancer immunotherapy, we review the specialized role of Tregs in clinically common and challenging organ sites of cancer metastasis, highlight research that describes Treg impacts on tissue-specific and systemic immune regulation in the context of immunotherapy, and summarize ongoing work reporting clinically feasible strategies that combine the specific targeting of Tregs with systemic cancer immunotherapy. Improved knowledge of Tregs in the framework of their tissue-specific biology and clinical sites of organ metastasis will enable more precise targeting of immunotherapy and have profound implications for treating patients with metastatic cancer.

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 cell profiles of metastatic HER2-positive breast cancer patients according to the sites of metastasis

PURPOSE

Recent works have characterized that metastatic site can affect the tumour immune profiles and efficiency of cancer immunotherapies. The prognosis of HER2-positive breast cancer is associated with the characteristics of the tumour immune microenvironment, with immunological cells playing a central role in efficiency of HER2-targeted antibodies. Here we investigated the prognostic significance of different metastatic sites and their correlation to tumour immune profiles in HER2-positive breast cancer treated with trastuzumab.

METHODS

We collected all (n = 54) HER2-positive metastatic breast cancer patients treated with trastuzumab containing regimens at Oulu University Hospital 2009-2014. Pathological and clinical data were collected from electronic patient records. The tumour immune profiles were analysed from pre-treatment primary tumours using well-characterized immunological markers with computer-assisted immune cell counting.

RESULTS

Of the metastatic sites, only liver metastases were associated with poor prognosis (hazard ratio 1.809, 95% confidence interval 1.004-3.262), especially when presented as the primary site of metastases. Of the other sites, pulmonary metastases characterized a patient profile with trend to improved survival. Of the studied tumour immunological markers, patients with liver metastases had low densities of CD3⁺ T cells (p = 0.030) and M1-like macrophages in their primary tumours (p = 0.025). Of the other studied markers and sites, patients with pulmonary metastases had low STAB1⁺-immunosuppressive macrophage density in their primary tumours.

CONCLUSION

Our results suggest that the site of metastasis is associated with prognosis in HER2-positive breast cancer, highlighted by the poor prognosis of liver metastases. Furthermore, liver metastases were associated with adverse tumour immune cell profiles.

Antimetastatic defense by CD8+ T cells

Metastasis is an intricate process whereby tumor cells migrate from the primary tumor, survive in the circulation, seed distal organs, and proliferate to create metastatic foci. CD8⁺ T cells can detect and eliminate tumor cells. Research on CD8⁺ T cell-dependent antitumor immunity has classically focused on its role in the primary tumor. There is increasing evidence, however, that CD8⁺ T cells have unique antimetastatic functions in various steps of the metastatic cascade. Here, we review the mechanisms whereby CD8⁺ T cells control metastatic lesions. We discuss their role in each step of metastasis, metastatic dormancy, and metastatic clonal evolution as well as the consequent clinical repercussions.

Uveal Melanoma Metastasis

Uveal melanoma (UM) is characterized by relatively few, highly incident molecular alterations and their association with metastatic risk is deeply understood. Nevertheless, this knowledge has so far not led to innovative therapies for the successful treatment of UM metastases or for adjuvant therapy, leaving survival after diagnosis of metastatic UM almost unaltered in decades. The driver mutations of UM, mainly in the G-protein genes GNAQ and GNA11, activate the MAP-kinase pathway as well as the YAP/TAZ pathway. At present, there are no drugs that target the latter and this likely explains the failure of mitogen activated kinase kinase inhibitors. Immune checkpoint blockers, despite the game changing effect in cutaneous melanoma (CM), show only limited effects in UM probably because of the low mutational burden of 0.5 per megabase and the unavailability of antibodies targeting the main immune checkpoint active in UM. The highly pro-tumorigenic microenvironment of UM also contributes to therapy resistance. However, T-cell redirection by a soluble T-cell receptor that is fused to an anti-CD3 single-chain variable fragment, local, liver specific therapy, new immune checkpoint blockers, and YAP/TAZ specific drugs give new hope to repeating the success of innovative therapy obtained for CM.

Radiotherapy and immunotherapy: open questions and future strategies

Immune checkpoint blockade (ICB) improves outcomes for some patients with advanced or metastatic cancers. Despite demonstrable progress, many patients do not respond to ICB. Recently, clinical trials have focused on combinations of ICB with radiation therapy. Although two recent Phase III randomized trials demonstrated improved survival with adjuvant ICB following chemoradiation, other Phase I/II/III trials are either negative or inconclusive, but do yield suggestive results and promising insights into future therapeutic strategies. We provide a selective review of a subset of these trials and attempt to integrate with basic laboratory findings where relevant to define issues pertaining to the combination of radiotherapy and immunotherapy.

The double-edged sword: Harnessing PD-1 blockade in tumor and autoimmunity

[Figure: see text].

Lenvatinib Targets FGF Receptor 4 to Enhance Antitumor Immune Response of Anti-Programmed Cell Death-1 in HCC

BACKGROUND AND AIMS

Recently, clinical trials of lenvatinib plus pembrolizumab in HCC have displayed an impressive objective response rate. This study aimed to clarify the mechanism for optimal patient selection.

APPROACH AND RESULTS

First, in patients with HCC, lenvatinib-treated recurrent tumors had lower programmed death ligand 1 (PD-L1) expression and regulatory T cell (Treg) infiltration compared with matched primary tumors. Consistently, in C57BL/6 wild-type mice receiving anti-programmed cell death 1 (PD-1) therapy, PD-L1 expression and Treg infiltration in s.c. tumors were reduced when adding lenvatinib to the scheme. Mechanistically, on the one hand, FGF receptor 4 (FGFR4) was the most pivotal target in PD-L1 down-regulation by lenvatinib in vitro. Furthermore, lenvatinib reinforced the proteasomal degradation of PD-L1 by blocking the FGFR4-glycogen synthase kinase 3β axis and rescued the sensitivity of interferon-γ-pretreated HCC cells to T-cell killing by targeting FGFR4. On the other hand, the level of IL-2 increased after anti-PD-1 treatment, but IL-2-mediated Treg differentiation was blocked by lenvatinib through targeting FGFR4 to restrain signal transducer and activator of transcription 5 (STAT5) phosphorylation. By regulating the variations in the number of Tregs and the tumor FGFR4 level in C57BL/6-forkhead box protein P3 (Foxp3^DTR ) mice, we found that high levels of FGFR4 and Treg infiltration sensitized tumors to the combination treatment. Finally, high levels of FGFR4 and Foxp3 conferred immune tolerance but better response to the combined therapy in patient cohorts.

CONCLUSIONS

Lenvatinib reduced tumor PD-L1 level and Treg differentiation to improve anti-PD-1 efficacy by blocking FGFR4. Levels of FGFR4 expression and Treg infiltration in tumor could serve as biomarkers for screening patients with HCC using lenvatinib plus anti-PD-1 combination therapy.

Real-world outcomes of regorafenib combined with immune checkpoint inhibitors in patients with advanced or metastatic microsatellite stable colorectal cancer: A multicenter study

Background

Treatment strategies are limited for patients with chemotherapy refractory microsatellite stable (MSS) colorectal cancer. We aim to evaluate the efficacy and safety of immune checkpoint inhibitors (ICIs) combined with regorafenib in this population in routine clinical practice.

Methods

We retrospectively analyzed patients with advanced or metastatic colorectal cancer who received at least one dose of ICIs combined with regorafenib in 14 Chinese medical centers. The primary outcome was objective response rate (ORR). This study was registered at ClinicalTrials.gov on February 2020 (NCT04771715).

Results

Eighty-four patients received ICIs combined with regorafenib from January 2019 to January 2021. Most patients (91%) received two or more systemic treatment lines before the study treatment. Seventy-six patients (90%) had confirmed MSS status. At a median follow-up of 5.5 months, four patients achieved partial response (5%) and 37 patients achieved stable disease (45%) as the best response. The median progression-free survival (PFS) was 3.1 months, and the median overall survival was 17.3 months. Eleven patients (13%) remained progression-free for more than 6 months. Baseline liver metastasis (HR 1.98, 95%CI 1.07–3.69, P = 0.03) and neutrophil–lymphocyte ratio (NLR) of ≥ 1.5 (HR 2.83, 95%CI 1.00–7.98, P = 0.05) were associated with shorter PFS in multivariate analysis. Grade 3 or higher treatment-related adverse events (TRAEs) occurred in 16 patients (19%).

Conclusion

The combination of ICIs with regorafenib can be a valuable treatment option for a proportion of patients with chemotherapy refractory MSS colorectal cancer. Patients with no liver metastasis and a low NLR at baseline may derive most benefit from this strategy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00262-021-03083-3.

Regulatory T-Cell Therapy in Liver Transplantation and Chronic Liver Disease

The constant exposure of the liver to gut derived foreign antigens has resulted in this organ attaining unique immunological characteristics, however it remains susceptible to immune mediated injury. Our understanding of this type of injury, in both the native and transplanted liver, has improved significantly in recent decades. This includes a greater awareness of the tolerance inducing CD4+ CD25+ CD127low T-cell lineage with the transcription factor FoxP3, known as regulatory T-Cells (Tregs). These cells comprise 5-10% of CD4+ T cells and are known to function as an immunological "braking" mechanism, thereby preventing immune mediated tissue damage. Therapies that aim to increase Treg frequency and function have proved beneficial in the setting of both autoimmune diseases and solid organ transplantations. The safety and efficacy of Treg therapy in liver disease is an area of intense research at present and has huge potential. Due to these cells possessing significant plasticity, and the potential for conversion towards a T-helper 1 (Th1) and 17 (Th17) subsets in the hepatic microenvironment, it is pre-requisite to modify the microenvironment to a Treg favourable atmosphere to maintain these cells' function. In addition, implementation of therapies that effectively increase Treg functional activity in the liver may result in the suppression of immune responses and will hinder those that destroy tumour cells. Thus, fine adjustment is crucial to achieve this immunological balance. This review will describe the hepatic microenvironment with relevance to Treg function, and the role these cells have in both native diseased and transplanted livers.

Combination Immunotherapies to Overcome Intrinsic Resistance to Checkpoint Blockade in Microsatellite Stable Colorectal Cancer

Although immune checkpoint inhibitors (ICIs) have shown promising results in the treatment of treating various malignancies, progress has been severely limited in metastatic colorectal cancer (mCRC). ICIs are effective in a fraction of patients with microsatellite instability-high mCRC but have little clinical efficacy in patients with microsatellite stable (MSS) mCRC, which accounts for 95% of mCRC cases. MSS mCRCs are considered to have intrinsic resistance to ICI monotherapy through multiple mechanisms. (1) They are poorly immunogenic because of their low tumor mutation burden; (2) frequent activation of the WNT/β-catenin signaling pathway excludes intratumoral CD8+ T cell immunity; (3) the tumor microenvironment is immunosuppressive because of the presence of various immunosuppressive cells, including tumor-associated macrophages and regulatory T cells; and (4) frequent liver metastasis in MSS mCRC may reduce the efficacy of ICIs. To overcome these resistance mechanisms, combination approaches using various agents, including STING agonists, MEK inhibitors, VEGF/R inhibitors, WNT/β-catenin inhibitors, oncolytic viruses, and chemo/radiotherapy, are actively ongoing. Preliminary evidence of the efficacy of some has been shown in early clinical trials. This review summarizes novel combination immunotherapy strategies described in recent preclinical and clinical studies to overcome the limitations of ICI monotherapy in MSS mCRC.

Glucocorticoid and PD-1 Cross-Talk: Does the Immune System Become Confused?

Programmed cell death protein 1 (PD-1) and its ligands, PD-L1/2, control T cell activation and tolerance. While PD-1 expression is induced upon T cell receptor (TCR) activation or cytokine signaling, PD-L1 is expressed on B cells, antigen presenting cells, and on non-immune tissues, including cancer cells. Importantly, PD-L1 binding inhibits T cell activation. Therefore, the modulation of PD-1/PD-L1 expression on immune cells, both circulating or in a tumor microenvironment and/or on the tumor cell surface, is one mechanism of cancer immune evasion. Therapies that target PD-1/PD-L1, blocking the T cell-cancer cell interaction, have been successful in patients with various types of cancer. Glucocorticoids (GCs) are often administered to manage the side effects of chemo- or immuno-therapy, exerting a wide range of immunosuppressive and anti-inflammatory effects. However, GCs may also have tumor-promoting effects, interfering with therapy. In this review, we examine GC signaling and how it intersects with PD-1/PD-L1 pathways, including a discussion on the potential for GC- and PD-1/PD-L1-targeted therapies to "confuse" the immune system, leading to a cancer cell advantage that counteracts anti-cancer immunotherapy. Therefore, combination therapies should be utilized with an awareness of the potential for opposing effects on the immune system.

Spatiotemporal Immune Landscape of Colorectal Cancer Liver Metastasis at Single-Cell Level

Liver metastasis, the leading cause of colorectal cancer mortality, exhibits a highly heterogeneous and suppressive immune microenvironment. Here, we sequenced 97 matched samples by using single-cell RNA-seq and Spatial Transcriptomics. Strikingly, metastatic microenvironment underwent remarkable spatial reprogramming of immunosuppressive cells such as MRC1+ CCL18+ M2-like macrophages. We further developed scMetabolism, a computational pipeline for quantifying single-cell metabolism, and observed that those macrophages harbored enhanced metabolic activity. Interestingly, neoadjuvant chemotherapy could block this status and restore the antitumor immune balance in responsive patients, while the non-responsive patients deteriorated into a more suppressive one. Our work described the immune evolution of metastasis and uncovered the black box of how tumors respond to neoadjuvant chemotherapy.

Toward personalized treatment approaches for non-small-cell lung cancer

Worldwide, lung cancer is the most common cause of cancer-related deaths. Molecular targeted therapies and immunotherapies for non-small-cell lung cancer (NSCLC) have improved outcomes markedly over the past two decades. However, the vast majority of advanced NSCLCs become resistant to current treatments and eventually progress. In this Perspective, we discuss some of the recent breakthrough therapies developed for NSCLC, focusing on immunotherapies and targeted therapies. We highlight our current understanding of mechanisms of resistance and the importance of incorporating genomic analyses into clinical studies to decipher these further. We underscore the future role of neoadjuvant and maintenance combination therapy approaches to potentially cure early disease. A major challenge to successful development of rational combination therapies will be the application of robust predictive biomarkers for clear-cut patient stratification, and we provide our views on clinical research areas that could influence how NSCLC will be managed over the coming decade.

Reinforcing the Combinational Immuno-Oncotherapy of Switching "Cold" Tumor to "Hot" by Responsive Penetrating Nanogels

Although immuno-oncotherapy in clinic has gained great success, the immunosuppressive tumor microenvironment (TME) existing in the "cold" tumor with insufficient and exhausted lymphocytes may result in a lower-than-expected therapeutic efficiency. Therefore, a properly designed synergistic strategy that can effectively turn the "cold" tumor to "hot" should be considered to improve the therapeutic effects of immuno-oncotherapy. Herein, TME-responsive penetrating nanogels (NGs) were developed, which can improve the delivery and penetration of the co-loaded resiquimod (R848) and green tea catechin (EGCG) in tumors by a nano-sized controlled releasing system of the soluble cyclodextrin-drug inclusion complex. Consequently, the NGs effectively promoted the maturation of dendritic cells, stimulated the cytotoxic T lymphocytes (CTLs), and decreased the PD-L1 expression in tumors. The combination of NGs with the OX40 agonist (αOX40) further synergistically enhanced the activation and infiltration of CTLs into the deep tumor and inhibited the suppression effects from the regulatory T cells (Tregs). As a result, an increased ratio of active CTLs to Tregs in tumors (20.66-fold) was achieved with a 91.56% tumor suppression effect, indicating a successful switch of "cold" tumors to "hot" for an immunologically beneficial TME with significantly improved anti-tumor immune therapeutics. This strategy could be tailored to other immuno-oncotherapeutic approaches to solve the urgent efficiency concerns of the checkpoint-based treatment in clinic.

Clinical Response to Immunotherapy Targeting Programmed Cell Death Receptor 1/Programmed Cell Death Ligand 1 in Patients With Treatment-Resistant Microsatellite Stable Colorectal Cancer With and Without Liver Metastases

IMPORTANCE

Microsatellite stable (MSS) metastatic colorectal cancer has been historically characterized as resistant to immunotherapy. Recent studies have demonstrated limited clinical activity of programmed cell death receptor 1/programmed death ligand 1 (PD-1/PD-L1) targeting in MSS metastatic colorectal cancer. The association of metastatic disease in the liver with treatment response has not been fully investigated.

OBJECTIVE

To investigate the association of liver metastases with response to PD-1/PD-L1-targeting therapy in MSS metastatic colorectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

This single-center retrospective cohort study evaluated clinical responses to PD-1- or PD-L1-targeting therapy, with or without other investigational agents, in patients with MSS metastatic colorectal cancer and disease progression after standard of care therapy from January 1, 2014, to December 31, 2020.

MAIN OUTCOMES AND MEASURES

Objective response rate (ORR) and progression-free survival (PFS), measured from initiation of PD-1/PD-L1-targeting therapy.

RESULTS

Ninety-five patients with MSS metastatic colorectal cancer were identified (54 men [56.8%]; median age, 55 [interquartile range (IQR), 49-64] years). The overall ORR was 8.4% (8 of 95 patients). Eight of 41 patients without liver metastases achieved an ORR of 19.5%, and no response was observed in 54 patients with liver metastases. The disease control rate was 58.5% (24 of 41) in patients without liver metastasis and 1.9% (1 of 54) in patients with liver metastasis. Patients without liver metastases at the time of PD-1/PD-L1-targeting treatment had a superior median PFS compared with patients with liver metastases (4.0 [IQR, 2.0-7.5] vs 1.5 [IQR, 1.0-2.0] months; P < .001). In addition, median PFS was 5.5 (IQR, 2.0-11.5) months for patients without any prior or current liver involvement at the time of PD-1/PD-L1-targeting treatment initiation. Using a multivariate Cox regression model correcting for Eastern Cooperative Oncology Group status, primary tumor location, RAS and BRAF status, tumor mutation burden, and metastatic sites, liver metastases was the variable with the most significant association with faster progression after PD-1/PD-L1 treatment inhibition (hazard ratio, 7.00; 95% CI, 3.18-15.42; P < .001).

CONCLUSIONS AND RELEVANCE

Findings of this cohort study suggest that patients with MSS metastatic colorectal cancer and without liver metastases may derive clinical benefits from checkpoint inhibitors, whereas the presence of liver metastases was associated with resistance. Further prospective studies are needed to investigate PD-1/PD-L1 inhibitors in patients with MSS metastatic colorectal cancer without liver metastases.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of breast cancer

Breast cancer has historically been a disease for which immunotherapy was largely unavailable. Recently, the use of immune checkpoint inhibitors (ICIs) in combination with chemotherapy for the treatment of advanced/metastatic triple-negative breast cancer (TNBC) has demonstrated efficacy, including longer progression-free survival and increased overall survival in subsets of patients. Based on clinical benefit in randomized trials, ICIs in combination with chemotherapy for the treatment of some patients with advanced/metastatic TNBC have been approved by the United States (US) Food and Drug Administration (FDA), expanding options for patients. Ongoing questions remain, however, about the optimal chemotherapy backbone for immunotherapy, appropriate biomarker-based selection of patients for treatment, the optimal strategy for immunotherapy treatment in earlier stage disease, and potential use in histological subtypes other than TNBC. To provide guidance to the oncology community on these and other important concerns, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline (CPG). The expert panel drew upon the published literature as well as their clinical experience to develop recommendations for healthcare professionals on these important aspects of immunotherapeutic treatment for breast cancer, including diagnostic testing, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence-based and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with breast cancer.

Mechanisms of regulatory T cell infiltration in tumors: implications for innovative immune precision therapies

With the broad application of cancer immunotherapies such as immune checkpoint inhibitors in multiple cancer types, the immunological landscape in the tumor microenvironment (TME) has become enormously important for determining the optimal cancer treatment. Tumors can be immunologically divided into two categories: inflamed and non-inflamed based on the extent of immune cell infiltration and their activation status. In general, immunotherapies are preferable for the inflamed tumors than for non-inflamed tumors. Regulatory T cells (Tregs), an immunosuppressive subset of CD4⁺ T cells, play an essential role in maintaining self-tolerance and immunological homeostasis. In tumor immunity, Tregs compromise immune surveillance against cancer in healthy individuals and impair the antitumor immune response in tumor-bearing hosts. Tregs, therefore, accelerate immune evasion by tumor cells, leading to tumor development and progression in various types of cancer. Therefore, Tregs are considered to be a crucial therapeutic target for cancer immunotherapy. Abundant Tregs are observed in the TME in many types of cancer, both in inflamed and non-inflamed tumors. Diverse mechanisms of Treg accumulation, activation, and survival in the TME have been uncovered for different tumor types, indicating the importance of understanding the mechanism of Treg infiltration in each patient when selecting the optimal Treg-targeted therapy. Here, we review recent advances in the understanding of mechanisms leading to Treg abundance in the TME to optimize Treg-targeted therapy. Furthermore, in addition to the conventional strategies targeting cell surface molecules predominantly expressed by Tregs, reagents targeting molecules and signaling pathways specifically employed by Tregs for infiltration, activation, and survival in each tumor type are illustrated as novel Treg-targeted therapies. The effectiveness of immune precision therapy depends on conditions in the TME of each cancer patient.

Tim-4+ cavity-resident macrophages impair anti-tumor CD8+ T cell immunity

Immune checkpoint blockade (ICB) has been a remarkable clinical advance for cancer; however, the majority of patients do not respond to ICB therapy. We show that metastatic disease in the pleural and peritoneal cavities is associated with poor clinical outcomes after ICB therapy. Cavity-resident macrophages express high levels of Tim-4, a receptor for phosphatidylserine (PS), and this is associated with reduced numbers of CD8+ T cells with tumor-reactive features in pleural effusions and peritoneal ascites from patients with cancer. We mechanistically demonstrate that viable and cytotoxic anti-tumor CD8+ T cells upregulate PS and this renders them susceptible to sequestration away from tumor targets and proliferation suppression by Tim-4+ macrophages. Tim-4 blockade abrogates this sequestration and proliferation suppression and enhances anti-tumor efficacy in models of anti-PD-1 therapy and adoptive T cell therapy in mice. Thus, Tim-4+ cavity-resident macrophages limit the efficacy of immunotherapies in these microenvironments.

Serum Amyloid A Proteins and Their Impact on Metastasis and Immune Biology in Cancer

Simple Summary

The liver responds to systemic inflammation and injury in a coordinated manner, called the acute phase response. While this normal physiological response aims to restore homeostasis, malignant transformation coopts this biology to increase the risk for metastasis, immune evasion, and therapeutic resistance. In this Review, we discuss the importance of acute phase response proteins in regulating cancer biology and treatment efficacy. We also consider potential strategies to intervene on acute phase biology as an approach to improve outcomes in cancer.

Abstract

Cancer triggers the systemic release of inflammatory molecules that support cancer cell metastasis and immune evasion. Notably, this biology shows striking similarity to an acute phase response that is coordinated by the liver. Consistent with this, a role for the liver in defining cancer biology is becoming increasingly appreciated. Understanding the mechanisms that link acute phase biology to metastasis and immune evasion in cancer may reveal vulnerable pathways and novel therapeutic targets. Herein, we discuss a link between acute phase biology and cancer with a focus on serum amyloid A proteins and their involvement in regulating the metastatic cascade and cancer immunobiology.