Prognostic impact of peritumoral lymphocyte infiltration in soft tissue sarcomas

Machine Vision-Detected Peritumoral Lymphocytic Aggregates are Associated with Disease-Free Survival in Papillary Thyroid Carcinoma Patients

Papillary thyroid carcinoma (PTC) is the most prevalent form of thyroid cancer, with a disease recurrence rate of around 20%. Lymphoid formations which occur in non-lymphoid tissues during chronic inflammatory, infectious, immune responses have been linked with tumor suppression. Lymphoid aggregates potentially enhance the body's anti-tumor response, offering an avenue for attracting tumor-infiltrating lymphocytes (TILs) and fostering their coordination. Increasing evidence highlights the role of lymphoid aggregate density in managing tumor invasion and metastasis, with a favorable impact noted on overall and disease-free survival (DFS) across various cancer types. In this work we present a machine vision model to predict recurrence in different histologic subtypes of PTC using measurements related to peritumoral lymphoid aggregate density. We demonstrate that quantifying the peritumoral lymphocytic presence is not only associated with associated with better prognosis, but along with TILs within the tumor, adds additional prognostic value in the absence of well-known second mutations including TERT. Annotations of peritumoral lymphoid aggregates on 171 well-differentiated PTCs in the TCGA-THCA dataset were used to train a deep-learning model to predict regions of lymphoid aggregates across the entire tissue. The fractional area of the tissue regions covered by these lymphocytes was dichotomized to determine two risk groups: significant and low density of peritumoral lymphocytes. DFS prognosticated using these risk groups via Kaplan-Meier (KM) analysis revealed a hazard ratio (HR)=2.51 (95% confidence interval (CI): 2.36, 2.66), tested on 170 new patients also from the TCGA-THCA dataset. The prognostic performance of peritumoral lymphocyte aggregate density were compared against univariate KM analysis of DFS using the fractional area of intratumoral lymphocytes within the primary tumor with HR = 2.04 (95% CI: 1.89, 2.19). Combining the lymphocyte features in and around the tumor yielded a statistically significantly improvement in prognostic performance (HR = 3.17 (95% CI: 3.02, 3.32)) on training and were independently evaluated against 62 patients outside TCGA-THCA with HR = 2.44 (95% CI: 2.19, 2.69). Multivariable Cox-regression analysis on the validation set revealed that the density of peritumoral and intratumoral lymphocytes were prognostic independent of histological subtype with a C-index = 0.815.

Immunological Tumor Microenvironment of Solitary Fibrous Tumors-Associating Immune Infiltrate with Variables of Prognostic Significance

BACKGROUND AND OBJECTIVES

Solitary fibrous tumors (SFTs) are morphologically heterogeneous tumors characterized by the NAB2::STAT6 gene fusion. Clinical outcomes may vary widely, and while most cases have favorable outcomes, some can progress to aggressive disease, manifesting as recurrence and metastasis, and ultimately resulting in patient death. Herein, we analyze the immunological tumor microenvironment (ITME) of SFTs, aiming to determine its prognostic value and correlation with established risk stratification systems (RSSs).

METHODS

A retrospective observational multicenter study of 52 fusion-confirmed SFTs with clinical follow-up data. Immunohistochemical analysis including CD163, CD68, CD3, CD8, CD20, PDL-1, PD-1, and LAG1 were evaluated in tissue microarrays, using an analog scale with scores ranging from 0 to 3 (0 = ≤9, 1 = 10-49, 2 = 50-99, and 3 = >100 positive cells per 10 high-power fields). The expression of these markers was correlated with clinical outcomes, morphological characteristics previously evaluated in whole slide tissue sections (hypercellularity/hypocellularity, round-oval or spindle dominant constituent cell (DCC) morphology, and necrosis), Ki67, overall survival, and RSS.

RESULTS

Only one of the fifty-two cases studied showed progression. In the multivariate analysis, neither the presence nor absence of immune cells (B-lymphocytes, T-lymphocytes, and macrophages) showed any association with the assessed RSSs (Demicco, Sugita, G-score, and Huang). Interestingly, the case that showed progression had high immune infiltrate with expression of CD68, CD163, CD8, and CD20 markers (score of 3). Round-oval cell morphology was associated with the presence of higher levels of CD163 macrophages. Lastly, the scant presence of CD20+ lymphocytes correlated with less necrosis, and cases with higher PDL-1 expression correlated with increased Ki67 values. All cases were negative for LAG-1 and PD-1.

CONCLUSIONS

SFT ITME components correlated with independent variables with prognostic significance. Nevertheless, ITME did not correlate with RSS scores.

Distinct leukocyte populations and cytokine secretion profiles define tumoral and peritumoral areas in renal cell carcinoma

Renal cell carcinoma (RCC) is a common malignancy frequently diagnosed at the metastatic stage. We performed a comprehensive analysis of the tumor immune microenvironment (TIME) in RCC patients, including the peritumoral tissue microenvironment, to characterize the phenotypic patterns and functional characteristics of infiltrating immune cells. T cells from various compartments (peripheral blood, tumor, peritumoral area, and adjacent healthy renal tissue) were assessed using flow cytometry and Luminex analyses, both before and after T cell-specific stimulation, to evaluate activation status and migratory potential. Our findings demonstrated that tumor-infiltrating lymphocytes (TILs) exhibited heightened cytokine production compared to peritumoral T cells (pTILs), acting as the primary source of cytotoxic markers (IFN-γ, granzyme B, and FasL). CD8+ T cells primarily employed Fas Ligand for cytotoxicity, while CD4+ T cells relied on CD107a. In addition, a statistically significant negative correlation between patient mortality and the presence of CD4+CD107+ pTILs was demonstrated. The engagement with the PD-1/PD-L1 pathway was also more evident in CD4+ and CD8+ pTILs as opposed to TILs. PD-L1 expression in the non-leukocyte fraction of the tumor tissue was relatively lower than in their leukocytic counterparts and upon stimulation, peripheral blood T cells displayed much stronger responses to stimulation than TILs and pTILs. Our results suggest that tumor and peritumoral T cells exhibit limited responsiveness to additional activation signals, while peripheral T cells retain their capacity to respond to stimulatory signals.

Durvalumab plus pazopanib combination in patients with advanced soft tissue sarcomas: a phase II trial

We aimed to determine the activity of the anti-VEGF receptor tyrosine-kinase inhibitor, pazopanib, combined with the anti-PD-L1 inhibitor, durvalumab, in metastatic and/or recurrent soft tissue sarcoma (STS). In this single-arm phase 2 trial (NCT03798106), treatment consisted of pazopanib 800 mg orally once a day and durvalumab 1500 mg once every 3 weeks. Primary outcome was overall response rate (ORR) and secondary outcomes included progression-free survival (PFS), overall survival, disease control rate, immune-related response criteria, and safety. The ORR was 30.4% and the trial met the pre-specified endpoint. The median PFS was 7.7 months (95% confidence interval: 5.7-10.4). The common treatment-related adverse events of grades 3-4 included neutropenia (9 [19.1%]), elevated aspartate aminotransferase (7 [14.9%]), alanine aminotransferase (5 [10.6%]), and thrombocytopenia (4 [8.5%]). In a prespecified transcriptomic analysis, the B lineage signature was a significant key determinant of overall response (P = 0.014). In situ analysis also showed that tumours with high CD20+ B cell infiltration and vessel density had a longer PFS (P = 6.5 × 10-4) than those with low B cell infiltration and vessel density, as well as better response (50% vs 12%, P = 0.019). CD20+ B cell infiltration was identified as the only independent predictor of PFS via multivariate analysis. Durvalumab combined with pazopanib demonstrated promising efficacy in an unselected STS cohort, with a manageable toxicity profile.

The interplay between neoantigens and immune cells in sarcomas treated with checkpoint inhibition

Introduction

Sarcomas are comprised of diverse bone and connective tissue tumors with few effective therapeutic options for locally advanced unresectable and/or metastatic disease. Recent advances in immunotherapy, in particular immune checkpoint inhibition (ICI), have shown promising outcomes in several cancer indications. Unfortunately, ICI therapy has provided only modest clinical responses and seems moderately effective in a subset of the diverse subtypes.

Methods

To explore the immune parameters governing ICI therapy resistance or immune escape, we performed whole exome sequencing (WES) on tumors and their matched normal blood, in addition to RNA-seq from tumors of 31 sarcoma patients treated with pembrolizumab. We used advanced computational methods to investigate key immune properties, such as neoantigens and immune cell composition in the tumor microenvironment (TME).

Results

A multifactorial analysis suggested that expression of high quality neoantigens in the context of specific immune cells in the TME are key prognostic markers of progression-free survival (PFS). The presence of several types of immune cells, including T cells, B cells and macrophages, in the TME were associated with improved PFS. Importantly, we also found the presence of both CD8+ T cells and neoantigens together was associated with improved survival compared to the presence of CD8+ T cells or neoantigens alone. Interestingly, this trend was not identified with the combined presence of CD8+ T cells and TMB; suggesting that a combined CD8+ T cell and neoantigen effect on PFS was important.

Discussion

The outcome of this study may inform future trials that may lead to improved outcomes for sarcoma patients treated with ICI.

Prognostic impact of the post-treatment T cell composition and spatial organization in soft tissue sarcoma patients treated with neoadjuvant hyperthermic radio(chemo)therapy

Soft tissue sarcomas (STS) form a heterogeneous group of tumors sharing a mesenchymal origin. Despite good local control of the disease, the occurrence of distant metastases often limits survival of STS patients with localized, high-risk tumors of the extremities. Accumulating evidence suggests a central role for the tumor immune microenvironment in determining the clinical outcome and response to therapy. Thus, it has been reported that STS patients with a high immune signature and especially presence of B cells and tertiary lymphoid structures display improved overall survival and response to checkpoint inhibitor treatment. Here, we explored the effect of curative multimodal therapy on the T cell landscape of STS using multiplex immunohistochemistry. We analyzed the phenotype, frequency, and spatial distribution of STS-infiltrating CD8+ T cells by staining for CD8, 4-1BB, Granzyme B, Ki67, PD-1, and LAG-3 as well as CD3+ T helper cells using a panel consisting of CD3, T-bet, GATA3, RORγT, FoxP3, and Ki67. All patients received neoadjuvant radiotherapy plus locoregional hyperthermia with or without chemotherapy. While the treatment-naïve biopsy sample allows an analysis of baseline T cell infiltration levels, both intra- and peritumoral areas of the matched resected tissue were analyzed to assess composition and spatial distribution of the T cell compartment and its therapeutic modulation. Generally, post-treatment tissues displayed lower frequencies of CD3+ and CD8+ T cells. Association with clinical data revealed that higher post-treatment frequencies of peritumoral and intratumoral CD3+ T cells and intratumoral PD-1+ CD8+ T cells were significantly associated with improved disease-free survival (DFS), while these densities had no prognostic significance in the biopsy. Upon spatial analysis, a high ratio of intratumoral to peritumoral CD8+ T cells emerged as an independent prognostic marker for longer DFS. These results indicate that the STS T cell landscape is altered by multimodal therapy and may influence the clinical outcome of patients. An enhanced understanding of the STS immune architecture and its modulation by neoadjuvant therapy may pave the way towards novel treatment modalities and improve the long-term clinical outcome of STS patients.

The clinical significance of perioperative inflammatory index as a prognostic factor for patients with retroperitoneal soft tissue sarcoma

BACKGROUND

The prognostic factors of retroperitoneal soft tissue sarcoma (STS) have been explored but not yet certain. This study evaluated the prognostic impact of various preoperative clinical parameters and inflammatory indices in primary STS, with a particular focus on the transition of inflammatory index before and after tumor resection in de-differentiated liposarcoma (DD-LPS).

METHODS

The clinical data of 113 patients with primary retroperitoneal STS receiving tumor resection were reviewed. Six variables (neutrophils, platelets, C-reactive protein (CRP), lymphocytes, albumin, and hemoglobin) in the blood samples were measured and nine inflammatory indices (neutrophil-lymphocyte ratio (NLR), CRP-lymphocyte ratio (CLR), platelet-lymphocyte ratio (PLR), neutrophil-albumin ratio (NAR), CRP-albumin ratio (CAR), platelet-albumin ratio (PAR), HALP (hemoglobin, albumin, lymphocyte and platelet), prognostic nutrition index (PNI), and modified Glasgow Prognostic Score (mGPS)) were calculated. The prognostic value of the indices was analyzed by univariate and multivariate analyses.

RESULTS

Elevated NLR, CLR, PLR, NAR, CAR, PAR, and mGPS were associated with a worse overall survival (p = 0.0124, 0.0011, 0.049, 0.0047, 0.0085, 0.0332, and 0.0086, respectively) in univariate analysis. Multivariate analysis showed that elevated CLR and DD-LPS were associated with poor overall survival (p = 0.0267 and 0.0218, respectively) in all retroperitoneal STS. In DD-LPD, patients with preoperative high CLR, whose postoperative CLR was normalized, demonstrated a favorable survival rate similar to those with preoperative low CLR.

CONCLUSIONS

Elevated CLR before surgery as well as DD-LPS were poor prognostic markers for overall survival in primary retroperitoneal STS. Perioperative CLR normalization may be related to a favorable prognosis in DD-LPS.

High endothelial venule is a surrogate biomarker for T-cell inflamed tumor microenvironment and prognosis in gastric cancer

Background

High endothelial venule (HEV) is a specialized vasculature for lymphocyte trafficking. While HEVs are frequently observed within gastric cancer (GC), the vascular–immune interaction between HEV and tumor-infiltrating lymphocytes (TILs) has not been well elucidated. In this study, we aimed to unveil the potential value of HEVs as a surrogate marker for T-cell inflamed immune microenvironment in GC using a large number of prospectively collected surgical specimens of GC.

Methods

We included 460 patients with GC who underwent surgical resection. Nanostring PanCancer immune profiling was performed to evaluate the immunological phenotype of GCs. HEV density and three distinct patterns of TILs (Crohn-like lymphoid reaction, peritumoral lymphoid reaction, and intratumoral lymphoid reaction) were analyzed for their relationship and evaluated as prognostic factors for relapse-free survival (RFS) and overall survival (OS).

Results

HEV-high GC revealed increased infiltration by immune cell subsets, including dendritic cells, CD8⁺ cytotoxic T cells, and CD4⁺ helper T cells. In addition, HEV-high GC demonstrated increased immune-modulating chemokines, type I or II interferon pathway, and immune checkpoints, all of which indicate the inflamed tumor microenvironment (TME). All three distinct patterns of TILs were associated with HEV density. In survival analysis, patients with HEV-high GC displayed significantly longer RFS and OS than those with HEV-low GC (p<0.001 for RFS, p<0.001 for OS). Multivariate analysis demonstrated that HEV was the most significant immunological prognostic factor for RFS (patients with high HEV compared with those with low HEV; HR 0.412, 95% CI 0.241 to 0.705, p=0.001) and OS (HR 0.547, 95% CI 0.329 to 0.909, p=0.02) after adjustment for age, stage, and TIL.

Conclusion

HEV is the most significant immunological prognosticator for RFS and OS in resected GC, indicating inflamed TME.

Phase II Study of Pembrolizumab in Combination with Doxorubicin in Metastatic and Unresectable Soft-Tissue Sarcoma

PURPOSE

Doxorubicin is standard therapy for advanced soft-tissue sarcoma (STS) with minimal improvement in efficacy and increased toxicity with addition of other cytotoxic agents. Pembrolizumab monotherapy has demonstrated modest activity and tolerability in previous advanced STS studies. This study combined pembrolizumab with doxorubicin to assess safety and efficacy in frontline and relapsed settings of advanced STS.

METHODS

This single-center, single-arm, phase II trial enrolled patients with unresectable or metastatic STS with no prior anthracycline therapy. Patients received pembrolizumab 200 mg i.v. and doxorubicin (60 mg/m² cycle 1 with subsequent escalation to 75 mg/m² as tolerated). The primary endpoint was safety. Secondary endpoints included overall survival (OS), objective response rate (ORR), and progression-free survival (PFS) based on RECIST v1.1 guidelines.

RESULTS

Thirty patients were enrolled (53.3% female; median age 61.5 years; 87% previously untreated) with 4 (13.3%) patients continuing treatment. The study met its primary safety endpoint by prespecified Bayesian stopping rules. The majority of grade 3+ treatment-emergent adverse events were hematologic (36.7% 3+ neutropenia). ORR was 36.7% [95% confidence interval (CI), 19.9-56.1%], with documented disease control in 80.0% (95% CI, 61.4-92.3%) of patients. Ten (33.3%) patients achieved partial response, 1 (3.3%) patient achieved complete response, and 13 (43.3%) patients had stable disease. Median PFS and OS were 5.7 months (6-month PFS rate: 44%) and 17 months (12-month OS rate: 62%), respectively. Programmed cell death ligand-1 (PD-L1) expression was associated with improved ORR, but not OS or PFS.

CONCLUSIONS

Combination pembrolizumab and doxorubicin has manageable toxicity and preliminary promising activity in treatment of patients with anthracycline-naive advanced STS.

T-regulatory cells predict clinical outcome in soft tissue sarcoma patients: a clinico-pathological study

BACKGROUND

Soft tissue sarcomas (STS) are generally considered non-immunogenic, although specific subtypes respond to immunotherapy. Antitumour response within the tumour microenvironment relies on a balance between inhibitory and activating signals for tumour-infiltrating lymphocytes (TILs). This study analysed TILs and immune checkpoint molecules in STS, and assessed their prognostic impact regarding local recurrence (LR), distant metastasis (DM), and overall survival (OS).

METHODS

One-hundred and ninety-two surgically treated STS patients (median age: 63.5 years; 103 males [53.6%]) were retrospectively included. Tissue microarrays were constructed, immunohistochemistry for PD-1, PD-L1, FOXP3, CD3, CD4, and CD8 performed, and staining assessed with multispectral imaging. TIL phenotype abundance and immune checkpoint markers were correlated with clinical and outcome parameters (LR, DM, and OS).

RESULTS

Significant differences between histology and all immune checkpoint markers except for FOXP3+ and CD3-PD-L1+ cell subpopulations were found. Higher levels of PD-L1, PD-1, and any TIL phenotype were found in myxofibrosarcoma as compared to leiomyosarcoma (all p < 0.05). The presence of regulatory T cells (Tregs) was associated with increased LR risk (p = 0.006), irrespective of margins. Other TILs or immune checkpoint markers had no significant impact on outcome parameters.

CONCLUSIONS

TIL and immune checkpoint marker levels are most abundant in myxofibrosarcoma. High Treg levels are independently associated with increased LR risk, irrespective of margins.

Diagnostic and prognostic role of neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, and lymphocyte/monocyte ratio in patients with osteosarcoma

OBJECTIVES

This study aims to evaluate the diagnostic and prognostic significance of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) values in patients with osteosarcoma.

PATIENTS AND METHODS

A total of 172 patients (111 males, 61 females; mean age: 24.3±15.3 years; range, 7 to 82 years) diagnosed with osteosarcoma in our institution between January 2002 and December 2018 were retrospectively analyzed. A total of 165 healthy individuals (115 males, 50 females; mean age: 20.2±9.2 years; range, 10 to 65 years) who did not have infectious, rheumatological or hematological diseases or any pathological finding were assigned as the control group. The clinical, laboratory, and demographic findings of the patients were obtained from hospital records. Pre-treatment NLR, PLR, and LMR values were calculated in all patients. Diagnostic and prognostic values of pre-treatment NLR, PLR and LMR were assessed using receiver operating curve (ROC) analysis. The Kaplan-Meier method was used for survival analysis.

RESULTS

For diagnostic approach, the highest significance in area under the curve (AUC) values was obtained for NLR (AUC=0.763). The AUC for PLR and LMR was statistically significant, while the statistical power was weak compared to NLR (AUC=0.681 and 0.603). The NLR, PLR, and LMR were found to be predictors of mortality. The cut-off value was found to be 3.28 for NLR, 128 for PLR, and 4.22 for LMR. The prognostic value of NLR for mortality was higher than (AUC=0.749) PLR (AUC=0.688) and LMR (AUC=0.609). The NLR, PLR, and LMR were associated with overall survival (OS). There was a significant difference in the median OS time among the NLR, PLR, and LMR values (log-rank test order p<0.001, p=0.001, and p=0.004, respectively).

CONCLUSION

Based on our study results, pre-treatment NLR, PLR and MLR have diagnostic and prognostic values in osteosarcoma.

Predicted CD4+ T cell infiltration levels could indicate better overall survival in sarcoma patients

OBJECTIVE

The role of tumor-infiltrating lymphocytes (TILs) has not yet been characterized in sarcomas. The aim of this bioinformatics study was to explore the effect of TILs on sarcoma survival and genome alterations.

METHODS

Whole-exome sequencing, transcriptome sequencing, and survival data of sarcoma were obtained from The Cancer Genome Atlas. Immune infiltration scores were calculated using the Tumor Immune Estimation Resource. Potential associations between abundance of infiltrating TILs and survival or genome alterations were examined.

RESULTS

Levels of CD4⁺ T cell infiltration were associated with overall survival of patients with pan-sarcomas, and higher CD4⁺ T cell infiltration levels were associated with better survival. Somatic copy number alterations, rather than mutations, were found to correlate with CD4⁺ T cell infiltration levels.

CONCLUSIONS

This data mining study indicated that CD4⁺ T cell infiltration levels predicted from RNA sequencing could predict sarcoma prognosis, and higher levels of CD4⁺ T cells infiltration indicated a better chance of survival.

CD11c-CD8 Spatial Cross Presentation: A Novel Approach to Link Immune Surveillance and Patient Survival in Soft Tissue Sarcoma

Checkpoint inhibitors are slowly being introduced in the care of specific sarcoma subtypes such as undifferentiated pleomorphic sarcoma, alveolar soft part sarcoma, and angiosarcoma even though formal indication is lacking. Proper biomarkers to unravel potential immune reactivity in the tumor microenvironment are therefore expected to be highly warranted. In this study, intratumoral spatial cross presentation was investigated as a novel concept where immune cell composition in the tumor microenvironment was suggested to act as a proxy for immune surveillance. Double immunohistochemistry revealed a prognostic role of direct spatial interactions between CD11c+ antigen-presenting cells (APCs) and CD8+ cells in contrast to each marker alone in a soft tissue sarcoma (STS) cohort of 177 patients from the Karolinska University Hospital (MFS p = 0.048, OS p = 0.025). The survival benefit was verified in multivariable analysis (MFS p = 0.012, OS p = 0.004). Transcriptomics performed in the TCGA sarcoma cohort confirmed the prognostic value of combining CD11c with CD8 (259 patients, p = 0.005), irrespective of FOXP3 levels and in a CD274 (PD-LI)-rich tumor microenvironment. Altogether, this study presents a histopathological approach to link immune surveillance and patient survival in STS. Notably, spatial cross presentation as a prognostic marker is distinct from therapy response-predictive biomarkers such as immune checkpoint molecules of the PD-L1/PD1 pathway.

Expanded Tumor-infiltrating Lymphocytes From Soft Tissue Sarcoma Have Tumor-specific Function

Adoptive cell transfer (ACT) with tumor-infiltrating lymphocytes (TILs) can generate durable clinical responses in patients with metastatic melanoma and ongoing trials are evaluating efficacy in other advanced solid tumors. The aim of this study was to develop methods for the expansion of tumor-reactive TIL from resected soft tissue sarcoma to a degree required for the ACT. From 2015 to 2018, 70 patients were consented to an institutional review board-approved protocol, and fresh surgical specimens were taken directly from the operating room to the laboratory. Fragments of the tumor (1 mm3) or fresh tumor digest were placed in culture for a period of 4 weeks. Successfully propagated TIL from these cultures were collected and analyzed by flow cytometry. TIL were cocultured with autologous tumor and function was assessed by measurement of interferon-γ in the supernatant by enzyme-linked immunosorbent assay. Initial TIL cultures were further expanded using a rapid expansion protocol. Nearly all specimens generated an initial TIL culture (91% fragment method, 100% digest method). The phenotype of the TIL indicated a predominant CD3+ population after culture (43% fragment, 52% digest) and TIL were responsive to the autologous tumor (56% fragment, 40% digest). The cultured TIL expanded to a degree required for clinical use following rapid expansion protocol (median: 490-fold fragment, 403-fold digest). The data demonstrate the feasibility of TIL culture from fresh soft tissue sarcoma. The derived TIL have tumor-specific reactivity and can be expanded to clinically relevant numbers. An active ACT clinical trial using the methods described in this report is now approved for patients with metastatic soft tissue sarcoma.

The paratumoral immune cell signature reveals the potential for the implementation of immunotherapy in esophageal carcinoma patients

PURPOSE

Esophageal cancer (EC) is one of the most lethal gastrointestinal malignancies. Immunotherapy is a promising treatment modality for this disease. However, broader implementation of EC immunotherapy has been discouraged because of insufficient understanding of tumor interactions with the immune system. As with other malignancies, the current research on EC focuses on deciphering the immune cell signatures within the tumor microenvironment. However, the disease-elicited immune cell profiles in the paratumoral compartments are largely unknown.

METHODS

We examined the immune cell signatures in 62 tissue samples from 16 EC patients in different esophageal tissue compartments: tumor tissue, peritumoral tissue, healthy esophageal tissue, and adjacent lymph nodes. We analyzed the proportions and distribution patterns of NK cells and CD4⁺ and CD8⁺ T cells as well as their death receptor (FasR, FasR/DR3)-expressing subpopulations. The analyzed data were then compared and correlated with the patients' clinicopathological data.

RESULTS

We found that the FasR⁺ NK cells, CD4⁺ and CD8⁺ T cells infiltrated lymph nodes at the lowest levels and that the FasR⁺DR3⁺ CD4⁺ T cells were enhanced in tumors. The comparisons with the clinicopathological data revealed a major impact of active smoking on the reduction in paratumoral NK cells and the upregulation of FasR in tumor-infiltrating NK and CD8⁺ T cells. The lymph node metastatic stage, tumor stage, and Mandard grade correlated with the compartmental proportions of the evaluated immune cells.

CONCLUSION

The novel association of the disease state with tumoral and paratumoral immune cell signatures suggests new possibilities for personalized immunotherapy for EC patients.

B cells are associated with survival and immunotherapy response in sarcoma

Soft-tissue sarcomas represent a heterogeneous group of cancer, with more than 50 histological subtypes^1,2. The clinical presentation of patients with different subtypes is often atypical, and responses to therapies such as immune checkpoint blockade vary widely^3,4. To explain this clinical variability, here we study gene expression profiles in 608 tumours across subtypes of soft-tissue sarcoma. We establish an immune-based classification on the basis of the composition of the tumour microenvironment and identify five distinct phenotypes: immune-low (A and B), immune-high (D and E), and highly vascularized (C) groups. In situ analysis of an independent validation cohort shows that class E was characterized by the presence of tertiary lymphoid structures that contain T cells and follicular dendritic cells and are particularly rich in B cells. B cells are the strongest prognostic factor even in the context of high or low CD8⁺ T cells and cytotoxic contents. The class-E group demonstrated improved survival and a high response rate to PD1 blockade with pembrolizumab in a phase 2 clinical trial. Together, this work confirms the immune subtypes in patients with soft-tissue sarcoma, and unravels the potential of B-cell-rich tertiary lymphoid structures to guide clinical decision-making and treatments, which could have broader applications in other diseases.

Sarcoma Tumor Microenvironment

Components of the tumor microenvironment (TME) are known to play an essential role during malignant progression, but often in a context-dependent manner. In bone and soft tissue sarcomas, disease-regulatory activities in the TME remain largely uncharacterized. This chapter introduces the cellular, structural, and chemical composition of the sarcoma TME from a pathobiological and therapeutic perspective.Sarcomas are malignant tumors with diverse features when it comes to primary tumor appearance, metastatic potential, and response to treatment. Many of the classic subtypes are mainly composed of malignant cells and are therefore assumed to be committed to autocrine signaling. Some of the tumors are infiltrated by immune cells and contain necrotic areas or excessive amounts of extracellular matrix (ECM) that regulates tissue stiffness and interstitial fluid pressure. Vascular invasion and blood vessel characteristics can in some instances be considered in the prognostic setting.Further insights into the disease-regulatory activities of the sarcoma TME will provide essential knowledge on how to develop successful combination treatments targeting not only malignant cells, but also their routes of nutrition and ability to shield themselves toward existing therapy.

Characterizing the immune microenvironment of malignant peripheral nerve sheath tumor by PD-L1 expression and presence of CD8+ tumor infiltrating lymphocytes

Background

Malignant peripheral nerve sheath tumor (MPNST) is an aggressive sarcoma with few treatment options. Tumor immune state has not been characterized in MPNST, and is important in determining response to immune checkpoint blockade. Our aim was to evaluate the expression of programmed death-ligand 1 (PD-L1), programmed cell death protein 1 (PD-1), and presence of CD8+ tumor infiltrating lymphocytes (TILs) in MPNST, and correlate these findings with clinical behavior and outcome.

Results

PD-L1 staining of at least 1% was seen in 0/20 nerves, 2/68 benign lesions and 9/53 MPNST. Two of 68 benign lesions and 7/53 (13%) MPNST had at least 5% PD-L1 staining. CD8 staining of at least 5% was seen in 1/20 (5%) nerves, 45/68 (66%) benign lesions and 30/53 (57%) MPNST. PD-L1 was statistically more prevalent in MPNST than both nerves and benign lesions (p=0.049 and p=0.008, respectively). Expression of PD-1 was absent in all tissue specimens. There was no correlation of PD-L1 or CD8 expression with disease state (primary versus metastatic) or patient survival.

Methods

A comprehensive PNST tissue microarray was created from 141 surgical specimens including primary, recurrent, and metastatic MPNST (n=53), neurofibromas (n=57), schwannoma (n=11), and normal nerve (n=20). Cores were stained in triplicate for PD-L1, PD-1, and CD8, and expression compared between tumor types. These data were then examined for survival correlates in 35 patients with primary MPNST.

Conclusions

MPNST is characterized by low PD-L1 and absent PD-1 expression with significant CD8+ TIL presence. MPNST immune microenvironment does not correlate with patient outcome.

Immune checkpoint inhibitors in sarcomas: in quest of predictive biomarkers

Sarcomas are a rare group of tumors of mesenchymal origin. Metastatic sarcomas are often difficult to treat and unresponsive to standard radio- and chemotherapy, resulting in a poor survival rate for patients. Novel treatments with immune checkpoint inhibitors have been proven to prolong survival of patients with a variety of cancers, including metastatic melanoma, lung, and renal cell carcinoma. Since immune checkpoint inhibitors could provide a novel treatment option for patients with sarcomas, clinical trials investigating their efficacy in these group of tumors are ongoing. However, the discrimination of patients that are the most likely to respond to these treatments is still an obstacle in the design of clinical trials. In this review, we provide a brief overview of the mechanisms of action of immune checkpoint inhibitors and discuss the proposed biomarkers of therapy response, such as lymphocytic infiltration, intratumoral PD-L1 expression, and mutational load in sarcomas.

PD-L1 and PD-1 and characterization of tumor-infiltrating lymphocytes in high grade sarcomas of soft tissue - prognostic implications and rationale for immunotherapy

Therapies targeting programmed death 1-(PD-1) or its ligand (PD-L1), promoting antitumor T-cell activity have been successfully introduced into clinical practice. Clinical response correlates with PD-L1 expression by tumor cells or immune cells within the tumor microenvironment. The PD-L1/PD-1 axis and tumor microenvironment has been rarely studied in high-grade sarcomas of soft tissue (hSTS), a group of rare, genetically heterogenous and clinically aggressive tumors. We examined PD-L1 protein and CD274/PD-L1 gene copy number variations in 128 primary resected, therapy-naive hSTS using immunohistochemistry and fluorescence-in-situ hybridization. Frequency of tumoral PD-L1 expression varied widely in different disease subentities, with highest rates of positivity (40%) seen in undifferentiated pleomorphic sarcomas (UPS) and rare positivity detected in synovial sarcomas (6%). Amplification of the CD274/PD-L1 gene occurred in 14% of UPS and was rare in other subtypes. PD-L1 protein expression was significantly more frequent in CD274/PD-L1 amplified cases (p = 0.015). The subgroup of UPS was further characterized regarding the interaction between PD-L1 and the immunologic tumor microenvironment. High density of CD3+ and CD8+ tumor infiltrating lymphocytes (TILs) was significantly correlated with the presence of PD-L1 expression and seen more frequently in tumors with lower TNM stage (p = 0.024). Both, PD-L1 expression and high density lymphocytic infiltration were independent prognostic factors for a favorable overall (p = 0.001, HR 6.105 (2.041-8.258)), disease-specific (p = 0.003, HR 10.536 (2.186-50.774)) and disease-free survival (p = 0.020, HR 3.317 (1.209-9.106); values for CD8) in this particular subgroup of hSTS, whereas PD-L1 expression in TILs or CD274/PD-L1 gene amplification were not associated with outcome. These findings represent novel insights into the immune landscape of soft tissue sarcomas, in particular UPS and strengthen the rationale for immunotherapy, including targeting the PD-1/PD-L1 axis in these tumors.

Clinicopathological significance of intratumoral and peritumoral lymphocytes and lymphocyte score based on the histologic subtypes of cutaneous melanoma

The presence of tumor infiltrating lymphocytes is a favorable prognostic factor in cutaneous melanoma, but their clinicopathological significance in the intratumoral compartment compared to the peritumoral compartment is unclear. We investigated the clinicopathologic significance of tumor-infiltrating lymphocytes and lymphocyte score in intra- and peritumoral compartments in 177 Korean patients who had undergone surgical excision of cutaneous melanoma. No significant correlation was observed between various clinicopathologic factors and the presence of intratumoral lymphocytes. However, high peritumoral lymphocyte scores were associated with lower Clark levels (P = 0.001), shallower Breslow thicknesses (P = 0.006), and fewer mitotic counts (P = 0.01) than tumors with lower scores. There was a trend for longer disease-free survival in cases with peritumoral lymphocytes (P = 0.07) than those without peritumoral lymphocytes. In patients with acral lentiginous melanoma, a strong association between a high peritumoral lymphocyte score and shallow Clark level was apparent (P = 0.03), and the presence of peritumoral lymphocytes (P = 0.02) and a high intratumoral lymphocyte score (P = 0.04) was also associated with longer disease-free survival. Particularly, low intratumoral lymphocyte score remarkably affected tumor recurrence and distant metastasis in a multivariate analysis using Cox regression test (H.R. = 0.304, 95% C.I. = 0.078–1.185, P = 0.09). Thus, the presence of lymphocytes and high lymphocyte scores in the intratumoral and peritumoral compartments are valid prognostic factors in cutaneous melanoma.

PDL1 expression is a poor-prognosis factor in soft-tissue sarcomas

Soft-tissue sarcomas (STS) are a group of rare, heterogeneous, and aggressive tumors, with high metastatic risk and relatively few efficient systemic therapies. In the quest for new treatments, the immune system represents an attractive therapeutic target. Recently, PD1/PDL1 inhibitors showed very promising results in patients with solid tumors. PDL1 expression has been rarely studied in STS, in small series only, by using immunohistochemistry (IHC), and with non-concordant prognostic implications. Here, we have analyzed PDL1 mRNA expression in 758 clinical STS samples retrospectively profiled using DNA microarrays and RNAseq, and searched for correlations with clinicopathological variables including metastasis-free survival (MFS) after surgery. PDL1 expression was heterogeneous across the samples. PDL1-high samples (41%) were more frequently leiomyosarcomas and liposarcomas, and showed more frequently a complex genetic profile and a high-risk CINSARC signature. No correlation existed with other clinicopathological features such as tumor site, depth, and pathological tumor grade and size. In multivariate prognostic analysis, the PDL1-high class was associated with shorter MFS, independently of the pathological type and the CINSARC signature. Analysis of correlations with biological factors suggested the existence in tumors of the PDL1-high class of a strong and efficient cytotoxic T-cell response, however associated with some degree of T-cell exhaustion and negative regulation. In conclusion, we show that PDL1 expression refines the prediction of metastatic relapse in operated localized STS, and that PD1/PDL1 blockade holds potential to improve patient survival by reactivating inhibited T cells to increase the antitumor immune in PDL1-high tumors.

Immunotherapy for Soft Tissue Sarcoma: Tomorrow Is Only a Day Away

Despite the advances taking place for patients with many types of cancer, to date there has been little success in meeting the great need for novel treatments of advanced soft tissue sarcoma with effective immunologic therapies. Here, we review recent clinical and preclinical data that indicate immune responses against sarcomas occur spontaneously and can also be successfully provoked. Efforts to manipulate the sarcoma immune microenvironment have the potential to eradicate disease and may also sensitize tumors to other tumor-targeted immunotherapeutic approaches. Other approaches, including vaccines and genetic engineering of T cells, offer a promising opportunity to actively direct cytotoxic lymphocytes toward antigen-bearing sarcomas. Drawing parallels with recent advances made in other cancer types, we identify ways in which sarcomas can be included in the ongoing immunotherapy revolution.

Immunotherapy for Resected Pulmonary Metastases

Micrometastatic disease following pulmonary metastasectomy is an ideal setting to test adjuvant immunotherapy, as the efficacy of immunotherapy in experimental models is greatest with the smallest tumor burdens. Although there is not a standard-of-care adjuvant immunotherapy for resected pulmonary metastases, there have been several studies using cytokines and other immunostimulatory molecules in conjunction with metastasectomies in patients with melanoma, renal cell carcinoma, sarcoma, and colorectal cancer, which have provided preliminary data that such adjuvant therapy is feasible and safe and may be useful in the future, following more rigorous testing, as routine therapy to prevent recurrences.

Increased CTLA-4(+) T cells and an increased ratio of monocytes with loss of class II (CD14(+) HLA-DR(lo/neg)) found in aggressive pediatric sarcoma patients

Background

There is little information regarding the composition of peripheral blood immunity in sarcoma patients and even less in the context of pediatric sarcomas. We describe the immune status using flow cytometry of peripheral blood in patients with osteosarcoma and Ewing sarcoma and demonstrate excessive CD14 in tumor tissues.

Methods

Peripheral blood from patients with OS and ES was collected at diagnosis or relapse, and used for immune phenotyping of 74 different leukocyte phenotypes. Blood from young adult healthy volunteers was collected as controls. Tumor tissues were analyzed by immunohistochemistry.

Results

Nineteen patients (average age = 14 y) and 16 controls (average age = 25y) were enrolled on study. Of the 74 phenotypes, 14 were different between sarcoma patients and HV. Sarcoma patients’ leukocytes contained a higher percentage of granulocytes (67 % sarcoma vs. 58 % HV; p = 0.003) and fewer lymphocytes (20 % sarcoma vs. 27 % HV; p = 0.001). Increased expression of CTLA-4 was seen in both T cells in sarcoma patients as compared to HV (p = 0.05). Increased CD14⁺ HLA-DR^lo/neg immunosuppressive monocytes were seen in sarcoma patients (p = 0.03); primarily seen in OS. Increased tumor necrosis factor receptor II expression was seen on CD14⁺ cells derived from sarcoma patients as compared to HV (p = 0.01). Massive infiltration of CD14⁺ cells was seen in OS (>50 % of cells in the majority of tumors) compared to ES (<10-25 % of cells). In contrast, both OS and ES had limited T cell infiltration (generally <10 % of cells).

Conclusions

Pediatric sarcoma patients exhibit several immune phenotypic differences that were exacerbated in more severe disease. These phenotypes have the potential to contribute to immune suppression and may indicate potential targets for immune therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-015-0082-0) contains supplementary material, which is available to authorized users.

Adoptive immunotherapy against sarcomas

INTRODUCTION

Conventional treatments reached an unsatisfactory therapeutic plateau in the treatment of advanced unresectable bone and soft tissue sarcomas that remain an unsolved medical need. Several evidences support the concept that adoptive immunotherapy may effectively integrate within the complex and multidisciplinary treatment of sarcomas.

AREAS COVERED

In this work we reviewed adoptive immunotherapy strategies that have been explored in sarcoma settings, with specific focus on issues related to their clinic transferability. We schematically divided approaches based on T lymphocytes specific for MHC-restricted tumor-associated antigens or relying on MHC-independent immune effectors such as natural killer (NK), cytokine-induced killer (CIK) or γδ T cells.

EXPERT OPINION

Preclinical findings and initial clinical reports showed the potentialities and drawbacks of different adoptive immunotherapy strategies. The expansion of tumor infiltrating lymphocytes is difficult to be reproduced outside melanoma. Genetically redirected T cells appear to be a promising option and initial reports are encouraging against patients with sarcomas. Adoptive immunotherapy with MHC-unrestricted effectors such as NK, CIK or γδ T cells has recently shown great preclinical potential in sarcoma setting and biologic features that may favor clinical transferability. Combination of different immunotherapy approaches and integration with conventional treatments appear to be key issues for successful designing of next clinical trials.

Sarcoma immunotherapy: past approaches and future directions

Sarcomas are heterogeneous malignant tumors of mesenchymal origin characterized by more than 100 distinct subtypes. Unfortunately, 25–50% of patients treated with initial curative intent will develop metastatic disease. In the metastatic setting, chemotherapy rarely leads to complete and durable responses; therefore, there is a dire need for more effective therapies. Exploring immunotherapeutic strategies may be warranted. In the past, agents that stimulate the immune system such as interferon and interleukin-2 have been explored and there has been evidence of some clinical activity in selected patients. In addition, many cancer vaccines have been explored with suggestion of benefit in some patients. Building on the advancements made in other solid tumors as well as a better understanding of cancer immunology provides hope for the development of new and exciting therapies in the treatment of sarcoma. There remains promise with immunologic checkpoint blockade antibodies. Further, building on the success of autologous cell transfer in hematologic malignancies, designing chimeric antigen receptors that target antigens that are over-expressed in sarcoma provides a great deal of optimism. Exploring these avenues has the potential to make immunotherapy a real therapeutic option in this orphan disease.

Prognostic impact of CD57, CD68, M-CSF, CSF-1R, Ki67 and TGF-beta in soft tissue sarcomas

Background

Prognostic markers in curable STS may have the potential to guide therapy after surgical resection. The purpose of this study was to clarify the prognostic impact of the presence of cells and growth factors belonging to the innate immune system in soft tissue sarcomas (STS). The significance of macrophages (CD68), their growth factor macrophage colony-stimulating factor (M-CSF), its receptor colony-stimulating factor-1 receptor (CSF-1R), natural killer cells (CD57) and the general immunomodulating molecule (TGF-beta) are all controversial in STS. Herein, these markers are evaluated and compared to the cell proliferation marker Ki67.

Methods

Tissue microarrays from 249 patients with non-gastrointestinal (non-GIST) STS were constructed from duplicate cores of viable and representative neoplastic tumor areas and duplicate cores of peritumoral capsule. Immunohistochemistry was used to evaluate the expression of CD68, M-CSF, CSF-1R, CD57, TGF-beta and Ki67 in tumor and peritumoral capsule.

Results

In univariate analyses increased expression of M-CSF (P = 0.034), Ki67 (P < 0.001) and TGF-beta (P = 0.003) in tumor correlated with shorter disease-specific survival (DSS). Increased expression of CD68 in tumor correlated significantly with malignancy grade (P = 0.016), but not DSS (P = 0.270). Increased expression of Ki67 in peritumoral capsule tended to correlate with a shorter DSS (P = 0.057). In multivariate analyses, co-expression of M-CSF and TGF-beta (P = 0.022) in tumor and high expression of Ki67 (P = 0.019) in peritumoral capsule were independent negative prognostic factors for DSS.

Conclusions

Increased co-expression of M-CSF and TGF-beta in tumor in patients with STS, and increased expression of Ki67 in peritumoral capsule were independent negative prognostic factors for DSS.