Tumor infiltrating PD1-positive lymphocytes and the expression of PD-L1 predict poor prognosis of soft tissue sarcomas

Expression of programmed cell death protein 1 and programmed cell death ligand 1 in feline injection site fibrosarcomas

Feline injection site fibrosarcomas represent a unique challenge in veterinary oncology due to their association with injection sites and aggressive behaviour. The study explores the expression of immune checkpoints programmed cell death protein 1 and programmed cell death ligand 1 in the malignancy, aiming to unravel their potential significance in tumour progression. The study included 31, archival diagnostic specimens of feline fibrosarcomas, located in the common injection sites. The programmed cell death protein 1 and programmed cell death ligand 1 expression in tumour cells and tumour infiltrating lymphocytes were assessed by immunohistochemical methods. Programmed cell death protein 1 and programmed cell death ligand 1 expression were observed in 84% and 81% of cases, respectively. In tumour infiltrating lymphocytes the PD-1 expression was observed in 71% of cases. Notably, higher programmed cell death protein 1 expression correlated with tumour grade and heightened inflammation score, suggesting a potential association with tumour aggressiveness. Similarly, programmed cell death ligand 1 expression exhibited a positive correlation with tumour grade and inflammation score. The observed findings suggest a potential role for programmed cell death protein 1 and programmed cell death ligand 1 in tumour progression and immune response within the tumour microenvironment. Moreover, this study contributes to a deeper understanding of feline injection site fibrosarcoma pathogenesis, emphasizing the importance of considering immunological perspectives in developing effective treatment strategies for this challenging condition. Further investigations are warranted to advance our knowledge and refine therapeutic approaches for feline injection site fibrosarcoma management.

Prognostic Role of OX40, LAG-3, TIM-3 and PD-L1 Expression in Bone and Soft Tissue Sarcomas

Introduction: The current study aims to evaluate the OX40, TIM-3, LAG-3, and PD-L1 targeted pathways in the regulation of T-cell activity in sarcoma patients to determine their relationship with overall survival (OS). Method: This study included one hundred and eleven patients with bone and soft tissue sarcoma diagnosed in two centers between 2010 and 2020. OX40, LAG-3, TIM-3 and PD-L1 expression levels were evaluated immunohistochemically from pathology preparations. Results: PD-L1 staining was detected in tumor cells, OX40, LAG-3, TIM-3 staining was detected in inflammatory cells in tumor tissue. In univariate analysis, no significant relationship was found between OX40, TIM-3, LAG-3, and PD-L1 staining and overall survival (respectively: p = 0.12, p = 0.49, p = 0.31, p = 0.95). When grade and stage at diagnosis, which were found to be significant in univariate analysis, along with OX-40, TIM-3, LAG-3, and PD-L1, were evaluated in multivariate analysis, a positive effect of OX-40 staining on overall survival was determined (p = 0.009). Considering the correlation between PDL-1 and OX40, TIM-3, and LAG-3 staining, a significant positive correlation was found between PDL-1 and TIM-3 and LAG-3 staining (respectively; p = 0.002, p = 0.001). Conclusions: There was no significant relationship between the PDL-1 staining percentage of tumor cells and OX40, TIM-3, and LAG-3 staining in inflammatory cells with the OS of sarcoma patients. However, detecting a significant positive correlation between PDL-1 staining and TIM-3 and LAG-3 staining also holds promise for finding effective targetable combination therapies that can prolong survival in sarcoma patients in the future.

Radiotherapy Combined with Intralesional Immunostimulatory Agents for Soft Tissue Sarcomas

Immunotherapy has shifted the treatment paradigm for many types of cancer. Unfortunately, the most commonly used immunotherapies, such as immune checkpoint inhibitors (ICI), have yielded limited benefit for most types of soft tissue sarcoma (STS). Radiotherapy (RT) is a mainstay of sarcoma therapy and can induce immune modulatory effects. Combining immunotherapy and RT in STS may be a promising strategy to improve sarcoma response to RT and increase the efficacy of immunotherapy. Most combination strategies have employed immunotherapies, such as ICI, that derepress immune suppressive networks. These have yielded only modest results, possibly due to the limited immune stimulatory effects of RT. Combining RT with immune stimulatory agents has yielded promising preclinical and clinical results but can be limited by the toxic nature of systemic administration of immune stimulants. Using intralesional immune stimulants may generate stronger RT immune modulation and less systemic toxicity, which may be a feasible strategy in accessible tumors such as STS. In this review, we summarize the immune modulatory effects of RT, the mechanism of action of various immune stimulants, including toll-like receptor agonists, and data for combinatorial strategies utilizing these agents.

Visual analysis of bone malignancies immunotherapy: A bibliometric analysis from 2010 to 2023

BACKGROUND

Bone malignancies (BM), including osteosarcoma, Ewing's sarcoma, chondrosarcoma, and chordoma, are characterized by high rates of recurrence and mortality, despite the availability of diverse treatment approaches. Immunotherapy has gained increasing importance in cancer treatment. However, there is a lack of comprehensive studies that utilize bibliometric analysis to explore immunotherapy for BM.

METHODS

A literature search of English studies on BM and immunotherapy from 2010 to 2023 was conducted in the Web of Science Core Collection database. Bibliometric analysis tools such as VOSviewer, CiteSpace, and R Studio were utilized to examine global trends and research hotspots in this field.

RESULTS

A total of 719 eligible articles, including 528 original research articles and 191 reviews, were analyzed. The number of publications has shown an increasing trend over the past 14 years, particularly in the last 5 years. The majority of the published articles on this topic originated from China (284 articles), followed by the United States and Japan. The institution with the highest number of publications and citations was the University of Texas MD Anderson Cancer Center (30 articles; 1638 citations). Dean A. Lee (12 articles) and Richard Gorlick (576 citations) were the authors with the highest contribution in terms of article count and citation count, respectively. Among these journals, Frontiers in Oncology had the highest number of articles (39 articles), while the Journal of Clinical Oncology had the highest number of citations (1878 citations). Additionally, there has been a shift in the keywords from "antitumor activity" and "NK cells" to popular topics such as "PD-L1," "open label," and "single arm."

CONCLUSION

A better understanding of the current status and prospects of immunotherapy for BM is crucial for the rationale selection of appropriate BM patients for immunotherapy. This study is expected to help clinical physicians and researchers gain comprehensive insights into the developmental trends of BM immunotherapy, providing practical guidance for the application of immunotherapy in BM patients.

Clinicopathologic Evaluation of CD80, CD86, and PD-L1 Expressions with Immunohistochemical Methods in Malignant Melanoma Patients

OBJECTIVE

Diagnostic and prognostic biomarkers for malignant melanoma are crucial for treatment and for developing targeted therapies. Malignant melanoma is a highly immunogenic tumor, and its regression, treatment, and prognostic evaluation are directly related to escape from immune destruction. Therefore, we aimed to determine the expression levels of CD80, CD86, and PD -L1 in malignant melanoma tissue samples by immunohistochemistry and to investigate the possible relationship between these proteins and the clinicopathological features in this study.

MATERIAL AND METHODS

Hematoxylin and eosin staining and immunohistochemical staining for CD80, CD86, and PD-L1 were evaluated for clinical data, survival, prognosis, tumor location, malignant melanoma subtypes, tumor size, and prognostic findings.

RESULTS

Higher survival rates were observed in patients with lower PD-L1 staining scores in the tumor. The 5-year survival was higher in patients with CD80-positive and CD86-positive biopsies. Mortality was lower in superficial spreading melanoma and Lentigo maligna melanoma types, whereas staining positivity of CD80 and CD86 was higher. Furthermore, a relationship between clinical stage and Breslow thickness ( < 2mm/≥2mm), tumor ulceration, lymph node metastasis, and CD80 and CD86 expression was also identified.

CONCLUSION

Our findings suggest that PD-L1, CD80, and CD86 expression are essential in malignant melanoma and could be used as prognostic markers.

Emerging innovations and advancements in the treatment of extremity and truncal soft tissue sarcomas

In this special edition update on soft tissue sarcomas (STS), we cover classifications, emerging technologies, prognostic tools, radiation schemas, and treatment disparities in extremity and truncal STS. We discuss the importance of enhancing local control and reducing complications, including the role of innovative imaging, surgical guidance, and hypofractionated radiation. We review advancements in systemic and immunotherapeutic treatments and introduce disparities seen in this vulnerable population that must be considered to improve overall patient care.

PROGNOSTIC IMPLICATIONS OF PD-L1 EXPRESSION AND LOSS OF PTEN IN PATIENTS WITH RHABDOMYOSARCOMA, EWING'S SARCOMA AND OSTEOSARCOMA

BACKGROUND

In children, osteosarcoma (OS), Ewing's sarcoma (ES), and rhabdomyosarcoma (RMS) are the most common sarcomas. A link between the anti-programmed death ligand-1 PD-L1 and the tumor suppressor phosphatase and tensin homologue (PTEN) expression has been described in many tumors. The aim of this work is to determine clinicopathological relationships and the possible prognostic significance of PD-L1 and PTEN expression in rhabdomyosarcoma (RMS), Ewing's sarcoma (ES), and osteosarcoma (OS).

MATERIALS AND METHODS

Expression of PD-L1 and PTEN were examined by immunohistochemistry in 45 archival RMS, ES, and OS cases.

RESULTS

The positive expression of PD-L1 was found in 16.7% and 31.6% of ES and OS, respectively. The negative PD-L1 was related to a substantially longer survival in ES cases (p = 0.045), but positive PD-L1 expression was significantly associated with the increased tumor stage and vascular invasion in the OS cases (p = 0.005 and p = 0.002), respectively. On the other hand, PTEN loss was strongly associated with deep tumor, high tumor grade, and recurrence in RMS (p = 0.002, p = 0.045, and p = 0.026, respectively). However, PTEN loss was significantly absent in ES as tumor grade increased (p = 0.031). It is noteworthy that tumor recurrence, the loss of PTEN, and positive PD-L1 were all considered predictive factors in OS patients (p = 0.045, p = 0.032, and p = 0.02, respectively).

CONCLUSIONS

In children, OS and ES have positive PD-L1 expression, which has an independent unfavorable prognostic effect and raises the possibility of using PD-L1 as a therapeutic target. OS, ES, and RMS prognosis are all predicted by PTEN loss.

Immune checkpoint inhibitors in sarcomas: a systematic review

Sarcomas are tumors that originate from mesenchymal cells. The variety of sarcomas' response to chemotherapy and the wide range of prognosis reflect their heterogeneity. In order to improve the rates of response, the research has been orientated toward other forms of therapy, such as targeted therapies and immunotherapy or toward combinations of them. Immune checkpoint inhibitors (ICIs) have been the highlight of immunotherapy in the last decade. Although ICIs are already included in the guidelines of different malignancies, their clinical benefit in sarcomas is still under study. Alveolar soft part sarcomas, undifferentiated pleomorphic sarcomas and other subtypes of sarcoma with high presence of tertiary lymphoid structures tend to respond to ICIs, but further investigation is still needed. Furthermore, the search of predictive biomarkers to determine the type of sarcomas that are sensitive to ICIs is still very challenging. This review will focus on the results of clinical trials, which examine the effect of ICIs and their combination with chemotherapy, targeted therapies and other forms of immunotherapy in sarcomas.

PD-1 receptor outside the main paradigm: tumour-intrinsic role and clinical implications for checkpoint blockade

Blocking the inhibitory receptor PD-1 on antitumour T lymphocytes is the main rationale underlying the clinical successes of cancer immunotherapies with checkpoint inhibitor (CI) antibodies (Abs). Besides this main paradigm, there is recent evidence of unconventional and "ectopic" signalling pathways of PD-1, found to be expressed not only by lymphocytes but also by peculiar subsets of cancer cells. Several groups reported on the tumour-intrinsic role of PD-1 in multiple settings, including melanoma, hepatocellular, thyroid, lung, pancreatic and colorectal cancer. Its functional activity appears intriguing but is not yet conclusively clarified. The initial studies are, in fact, supporting either a pro-tumourigenic role involved in chemoresistance and disease relapse or, oppositely, tumour-suppressive functions. The implications connected to the therapeutic administration of PD-1 blocking Abs are, of course, potentially relevant, respectively inferring an anti-tumour activity contrasting PD-1+ tumourigenic cells or a pro-tumoural effect by tackling PD-1 tumour suppressive signalling. The progressive exploration and consideration of this new paradigm of tumour-intrinsic PD-1 signalling may improve the interpretation of the observed clinical effects by anti-PD-1 Abs, likely resulting from multiple cumulative activities, and might provide important bases for dedicated clinical studies that take into account such composite roles of PD-1.

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.

FAM83H Expression Is Associated with Tumor-Infiltrating PD1-Positive Lymphocytes and Predicts the Survival of Breast Carcinoma Patients

BACKGROUND

FAM83H has been implicated in cancer progression, and PD1 is an important target for anti-cancer immune checkpoint therapy. Recent studies suggest an association between FAM83H expression and immune infiltration. However, studies on the roles of FAM83H and its relationship with PD1 in breast carcinomas have been limited.

METHODS

Immunohistochemical expression of FAM83H and PD1 and their prognostic significance were evaluated in 198 breast carcinomas.

RESULTS

The expression of FAM83H in cancer cells was significantly associated with the presence of PD1-positive lymphoid cells within breast carcinoma tissue. Individual and co-expression patterns of nuclear FAM83H and PD1 were significantly associated with shorter survival of breast carcinomas in univariate analysis. In multivariate analysis, the expression of nuclear FAM83H (overall survival, p < 0.001; relapse-free survival, p = 0.003), PD1 (overall survival, p < 0.001; relapse-free survival, p = 0.003), and co-expression patterns of nuclear FAM83H and PD1 (overall survival, p < 0.001; relapse-free survival, p < 0.001) were the independent indicators of overall survival and relapse-free survival of breast carcinoma patients.

CONCLUSIONS

This study suggests a close association between FAM83H expression and the infiltration of PD1-positive lymphoid cells in breast carcinomas and their expression as the prognostic indicators for breast carcinoma patients, and further studies are needed to clarify this relationship.

Biomarkers for immune checkpoint inhibition in sarcomas - are we close to clinical implementation?

Sarcomas are a group of diverse and complex cancers of mesenchymal origin that remains poorly understood. Recent developments in cancer immunotherapy have demonstrated a potential for better outcomes with immune checkpoint inhibition in some sarcomas compared to conventional chemotherapy. Immune checkpoint inhibitors (ICIs) are key agents in cancer immunotherapy, demonstrating improved outcomes in many tumor types. However, most patients with sarcoma do not benefit from treatment, highlighting the need for identification and development of predictive biomarkers for response to ICIs. In this review, we first discuss United States (US) Food and Drug Administration (FDA)-approved and European Medicines Agency (EMA)-approved biomarkers, as well as the limitations of their use in sarcomas. We then review eight potential predictive biomarkers and rationalize their utility in sarcomas. These include gene expression signatures (GES), circulating neutrophil-to-lymphocyte ratio (NLR), indoleamine 2,3-dioxygenase (IDO), lymphocyte activation gene 3 (LAG-3), T cell immunoglobin and mucin domain-containing protein 3 (TIM-3), TP53 mutation status, B cells, and tertiary lymphoid structures (TLS). Finally, we discuss the potential for TLS as both a predictive and prognostic biomarker for ICI response in sarcomas to be implemented in the clinic.

Dedifferentiated Chondrosarcoma from Molecular Pathology to Current Treatment and Clinical Trials

Dedifferentiated chondrosarcoma (DDCS) is a rare subtype of chondrosarcoma, a primary cartilaginous malignant neoplasm. It accounts for up to 1-2% of all chondrosarcomas and is generally associated with one of the poorest prognoses among all chondrosarcomas with the highest risk of metastasis. The 5-year survival rates range from 7% to 24%. DDCS may develop at any age, but the average presentation age is over 50. The most common locations are the femur, pelvis humerus, scapula, rib, and tibia. The standard treatment for localised disease is surgical resection. Most patients are diagnosed in unresectable and advanced stages, and chemotherapy for localised and metastatic dedifferentiated DDCS follows protocols used for osteosarcoma.

Tumor Microenvironment and Its Clinicopathologic and Prognostic Association in Cutaneous and Noncutaneous Angiosarcomas

OBJECTIVES

We explored features of the angiosarcoma (AS) tumor microenvironment to discover subtypes that may respond to immunotherapy.

METHODS

Thirty-two ASs were included. Tumors were studied by histology, immunohistochemistry (IHC), and gene expression profile using the HTG EdgeSeq Precision Immuno-Oncology Assay.

RESULTS

Comparing cutaneous and noncutaneous ASs, the second group showed 155 deregulated genes, and unsupervised hierarchical clustering (UHC) delineated two groups: the first mostly cutaneous AS and the second mainly noncutaneous AS. Cutaneous ASs showed a significantly higher proportion of T cells, natural killer cells, and naive B cells. ASs without MYC amplification revealed a higher immunoscore in comparison with ASs with MYC amplification. PD-L1 was significantly overexpressed in ASs without MYC amplification. UHC showed 135 deregulated genes differentially expressed when comparing ASs from the non-head and neck area with patients who had AS in the head and neck area. ASs from the head and neck area showed high immunoscore. PD1/PD-L1 content was significantly more highly expressed in ASs from the head and neck area. IHC and HTG gene expression profiling revealed a significant correlation between PD1, CD8, and CD20 protein expression but not PD-L1.

CONCLUSIONS

Our HTG analyses confirmed a high degree of tumor and microenvironment heterogeneity. Cutaneous ASs, ASs without MYC amplification, and ASs located in the head and neck area seem to be the most immunogenic subtypes in our series.

Treatment of De-Differentiated Liposarcoma in the Era of Immunotherapy

Well-differentiated/de-differentiated liposarcoma (WDLPS/DDLPS) is one of the most common histologic subtypes of soft tissue sarcoma (STS); however, treatment options remain limited. WDLPS and DDLPS both exhibit the characteristic amplification of chromosome region 12q13-15, which contains the genes CDK4 and MDM2. DDLPS exhibits higher amplification ratios of these two and carries additional genomic lesions, including the amplification of chromosome region 1p32 and chromosome region 6q23, which may explain the more aggressive biology of DDLPS. WDLPS does not respond to systemic chemotherapy and is primarily managed with local therapy, including multiple resections and debulking procedures whenever clinically feasible. In contrast, DDLPS can respond to chemotherapy drugs and drug combinations, including doxorubicin (or doxorubicin in combination with ifosfamide), gemcitabine (or gemcitabine in combination with docetaxel), trabectedin, eribulin, and pazopanib. However, the response rate is generally low, and the response duration is usually short. This review highlights the clinical trials with developmental therapeutics that have been completed or are ongoing, including CDK4/6 inhibitors, MDM2 inhibitors, and immune checkpoint inhibitors. This review will also discuss the current landscape in assessing biomarkers for identifying tumors sensitive to immune checkpoint inhibitors.

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.

Targeting the Molecular and Immunologic Features of Leiomyosarcoma

Leiomyosarcoma (LMS) is a rare, aggressive mesenchymal tumor with smooth muscle differentiation. LMS is one of the most common histologic subtypes of soft tissue sarcoma; it most frequently occurs in the extremities, retroperitoneum, or uterus. LMS often demonstrates aggressive tumor biology, with a higher risk of developing distant metastatic disease than most sarcoma histologic types. The prognosis is poor, particularly in patients with uterine disease, and there is a need for the development of more effective therapies. Genetically, LMS is karyotypically complex and characterized by a low tumor mutational burden, with frequent alterations in TP53, RB1, PTEN, and DNA damage response pathways that may contribute to resistance against immune-checkpoint blockade monotherapy. The LMS immune microenvironment is highly infiltrated with tumor-associated macrophages and tumor-infiltrating lymphocytes, which may represent promising biomarkers. This review provides an overview of the clinical and pathologic behavior of both soft tissue and uterine LMS and summarizes the genomic and immune characteristics of these tumors and how they may provide opportunities for the development of biomarker-based immune therapies.

PD-L1 immunohistochemistry assay optimization to provide more comprehensive pathological information in classic Hodgkin lymphoma

Overexpression of PD-L1 can be a predictive marker for anti-PD-1 therapeutic efficacy in classic Hodgkin lymphoma (CHL); however, harmonization of different IHC assays remains to be accomplished, and interpretations of PD-L1 immunostaining results remain controversial in CHL. In this study, we sought to optimize the PD-L1 immunohistochemistry (IHC) assay in CHL. All tests were performed on a tumour tissue microarray established from 54 CHL cases. Three IHC antibodies (405.9A11, SP142, 22C3) for detecting PD-L1 expression were compared semi quantitatively with the RNAscope assay (No. 310035, ACD), and the difference in the expression in background immune cells (ICs) between assays and the associations of expression levels with densities of TILs/TAMs were also analysed. 405.9A11 demonstrated best specificity in HRS cells and best sensitivity in ICs. Positive expression of PD-L1 was more frequent in ICs (85.2%) than in HRS cells (48.1%). Different subgroups of background ICs, including tumour-associated macrophages (TAMs), were assessed and scored for CD4, CD8, FOXP3, and CD163 expression. PD-L1 expression on ICs was the factor most associated with the density of TAMs. 405.9A11 provided the most convincing PD-L1 expression results. Pathologists should report PD-L1 expression in a combined manner, including both the status of HRS cells and the percentage of PD-L1-positive ICs.

Exploring the landscape of immunotherapy approaches in sarcomas

Sarcomas comprise a heterogenous group of malignancies, of more than 100 different entities, arising from mesenchymal tissue, and accounting for 1% of adult malignancies. Surgery, radiotherapy and systemic therapy constitute the therapeutic armamentarium against sarcomas, with surgical excision and conventional chemotherapy, remaining the mainstay of treatment for local and advanced disease, respectively. The prognosis for patients with metastatic disease is dismal and novel therapeutic approaches are urgently required to improve survival outcomes. Immunotherapy, is a rapidly evolving field in oncology, which has been successfully applied in multiple cancers to date. Immunomodulating antibodies, adoptive cellular therapy, cancer vaccines, and cytokines have been tested in patients with different types of sarcomas through clinical trials, pilot studies, retrospective and prospective studies. The results of these studies regarding the efficacy of different types of immunotherapies in sarcomas are conflicting, and the application of immunotherapy in daily clinical practice remains limited. Additional clinical studies are ongoing in an effort to delineate the role of immunotherapy in patients with specific sarcoma subtypes.

Tislelizumab immunotherapy combined with chemotherapy in the treatment of a patient with primary anterior mediastinal undifferentiated pleomorphic sarcoma with high PD-L1 expression: A case report and literature review

Undifferentiated pleomorphic sarcoma (UPS) is a rare and aggressive soft tissue tumor with a high degree of malignancy and rapid progression, usually occurring in the extremities, retroperitoneum, and abdomen, whereas it rarely arises in the mediastinum, and is treated mainly by surgical resection. The prognosis of patients with advanced sarcoma is poor, and doxorubicin monotherapy is the standard first-line chemotherapy for most advanced soft tissue sarcomas (STS), but the prognosis is generally unsatisfactory. Immune checkpoint inhibitors (ICIs) have been established as therapies for many solid cancers in recent years; however, evidence on the efficacy of ICIs in undifferentiated sarcoma is scarce, mostly consisting of small studies, and no ICIs are currently approved for use in sarcomas. We report a case of a middle-aged man with primary mediastinal UPS with high PD-L1 expression (TPS was approximately 80%) and TLS positive. The patient was treated with sequential tislelizumab monotherapy maintenance after 6 cycles of tislelizumab combined with epirubicin, efficacy evaluation was partial remission (PR), progression-free survival (PFS) was 8.5 months, and grade 1 fatigue was identified as an adverse event.

Combinations of Chemotherapy and PD-1/PD-L1 Inhibitors in Sarcoma

OPINION STATEMENT

While no PD-1 inhibitor has been FDA approved for use in sarcoma or proven efficacious in a randomized trial, the use of single agent PD-1 inhibitors is standard-of-care and recommended by the NCCN guidelines in certain specific subtypes and situations. Even while the role of immunotherapy is still being defined in sarcoma, there is rising interest in combinations of PD-1 inhibitors with standard-of-care treatments, especially chemotherapy. Recently, several early phase trials have suggested potential benefits for chemotherapy in combination with PD-1 inhibitors. Although some physicians are already combining PD-1 inhibitors and chemotherapy for sarcoma off-label in the community, we believe more data is necessary. We support further evaluation of these combinations in well-designed clinical trials.

Case report: Treatment of metastatic dedifferentiated chondrosarcoma with pembrolizumab yields sustained complete response

Dedifferentiated chondrosarcomas (DDCS) are aggressive tumors with poor outcomes. Treatment of localized DDCS is primarily surgical, though most patients present with unresectable or metastatic disease. Systemic treatment options for advanced DDCS are limited, and the benefits of chemotherapy in this patient population remain controversial. Among other systemic therapy options, there is emerging clinical evidence to support the use of immunotherapy in patients with advanced DDCS. However, studies regarding the efficacy of immunotherapy in advanced DDCS are limited. Here, we present the case of a patient with metastatic, programmed death-ligand 1 (PD-L1)-positive DDCS treated with pembrolizumab who showed a sustained complete response for 24 months after initiation of therapy. To our knowledge, this case represents one of few documented cases of metastatic chondrosarcoma with sustained response to immunotherapy. The impressive response seen with PD-L1 inhibition in our patient indicates that immunotherapy is a successful treatment option in a subset of DDCS patients, and further investigation is needed to identify potential responders to immunotherapy.

A ferroptosis-related gene signature associated with immune landscape and therapeutic response in osteosarcoma

BACKGROUND

The role of ferroptosis in tumor progression and immune microenvironment is extensively investigated. However, the potential value of ferroptosis regulators in predicting prognosis and therapeutic strategies for osteosarcoma (OS) patients remains to be elucidated.

METHODS

Here, we extracted transcriptomic and survival data from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Gene Expression Omnibus (GEO) to investigate the expression and prognostic value of ferroptosis regulators in OS patients. After comprehensive analyses, including Gene set variation analysis (GSVA), single-sample gene-set enrichment analysis (ssGSEA), Estimated Stromal and Immune cells in Malignant Tumor tissues using Expression (ESTIMATE), single-cell RNA sequencing, and biological experiments, our constructed 8-ferroptosis-regulators prognostic signature effectively predicted the immune landscape, prognosis, and chemoradiotherapy strategies for OS patients.

RESULTS

We constructed an 8-ferroptosis-regulators signature that could predict the survival outcome of OS. The signature algorithm scored samples, and high-scoring patients were more prone to worse prognoses. The tumor immune landscape suggested the positive relevance between risk score and immunosuppression. Interfering HILPDA and MUC1 expression would inhibit tumor cell proliferation and migration, and MUC1 might improve the ferroptosis resistance of OS cells. Moreover, we predicted chemoradiotherapy strategies of cancer patients following ferroptosis-risk-score groups.

CONCLUSION

Dysregulated ferroptosis gene expression can affect OS progression by affecting the tumor immune landscape and ferroptosis resistance. Our risk model can predict OS survival outcomes, and we propose that HILPDA and MUC1 are potential targets for cancer therapy.

Comparative Combinatorial Implications and Theranostics of Immunotherapy in the Impediment of Alveolar Soft Part Sarcoma

BACKGROUND

Immune checkpoint inhibitors (ICIs), specifically programmed cell death receptor- 1/ligand 1 (PD-1/L1) inhibitors, have shown potential pharmacological efficacy in several cancers. Nonetheless, data pertinent to their therapeutic efficacy in alveolar soft-part sarcoma (ASPS) are limited.

OBJECTIVE

The retrospective aspects of ICIs (anti-PD1/PD-L1 blockers) to target ASPS are comparatively analyzed for clinical outcomes with other targeted immunotherapy modalities.

METHODS

We have conducted a systematic review without statistical analysis or comprehensive meta-analysis by collecting the articles published between 1952 and Sep 10th, 2020, by searching the following words: alveolar soft part sarcoma and immunotherapy including immune checkpoint, immune checkpoint inhibitors, and PD-1, PD-L1. We performed a pooled analysis of case reports, conferences, clinical trials, and other research reports pertinent to the efficacy of a PD-1 or PD-L1 antagonist in patients diagnosed with metastatic ASPS.

RESULTS

The effective studies include 10 case reports, 2 conference reports, 5 clinical trials, and 2 additional research reports. A total of 110 patients were reported to be enrolled in the pooled analysis; among them, 87 (78.38%) received a PD-1/PD-L1 antagonist. For patients who received anti-PD-1/PD-L1as monotherapy, their clinical response rates (CRR) were 63.22% whereas those who received targeted therapy and immunotherapy had a CRR of 78.95% (15/19). In the patients treated with double immunotherapy, their CRR was 100% (4/4). Tumor mutational burden and mismatch repair status have significant implications for predicting the ASPS prognosis.

CONCLUSION

Alveolar soft-part sarcoma patients with distant metastases can exhibit better clinical outcomes with immunotherapy, particularly toripalimab, atezolizumab, and axitinib combinatorial regimen with pembrolizumab. In addition, this review describes the therapeutic implications to guide personalized medicine depending on the expression patterns of PD-1/PD-L1 during the immunotherapy with ASPS.

Immunotherapy for liposarcoma: emerging opportunities and challenges

Liposarcoma (LPS) is a rare adipocyte-derived malignancy accounting for 20% of all soft tissue sarcomas. Although surgery and chemotherapy are the standard treatment for LPS, the large tumor burden and high recurrence rate make it difficult to treat, especially when the disease progresses. With the progress of immunotherapies in other tumors such as melanoma and lung cancer, interest has been risen in exploring immunotherapy for LPS. This review discusses the understanding of the tumor microenvironment of LPS; the current status of immunotherapy in LPS, including immune checkpoint inhibitors, adoptive cell therapy, cancer vaccines, oncolytic viruses and combination therapies; and the future directions for exploiting strategies to make the effect of immunotherapy stronger and more durable.

The Immune Contexture of Liposarcoma and Its Clinical Implications

Liposarcomas (LPS) are the most frequent malignancies in the soft tissue sarcoma family and consist of five distinctive histological subtypes, termed well-differentiated LPS, dedifferentiated LPS (DDLPS), myxoid LPS (MLPS), pleomorphic LPS, and myxoid pleomorphic LPS. They display variations in genetic alterations, clinical behavior, and prognostic course. While accumulating evidence implicates a crucial role of the tumor immune contexture in shaping the response to anticancer treatments, the immunological landscape of LPS is highly variable across different subtypes. Thus, DDLPS is characterized by a higher abundance of infiltrating T cells, yet the opposite was reported for MLPS. Interestingly, a recent study indicated that the frequency of pre-existing T cells in soft tissue sarcomas has a predictive value for immune checkpoint inhibitor (CPI) therapy. Additionally, B cells and tertiary lymphoid structures were identified as potential biomarkers for the clinical outcome of LPS patients and response to CPI therapy. Furthermore, it was demonstrated that macrophages, predominantly of M2 polarization, are frequently associated with poor prognosis. An improved understanding of the complex LPS immune contexture enables the design and refinement of novel immunotherapeutic approaches. Here, we summarize recent studies focusing on the clinicopathological, genetic, and immunological determinants of LPS.

Immunohistochemical Expression of Programmed Death Ligand 1 in Oral Extranodal Diffuse Large B Cell Lymphoma

OBJECTIVE

 Lymphomas are the third most common cancer after squamous cell carcinoma and salivary gland tumors. Extranodal diffuse B cell lymphoma (DBCL) represents 30 to 58% of non-Hodgkin's lymphoma. One of the major problems of DBCL is the high likelihood of disease relapse following treatment. A recent trend in the treatment of diffuse large B cell lymphoma (DLBCL) is blockage of an immune checkpoint inhibitor that targets the programmed death of cell ligand 1 receptors (PD-L1). PD-L1 activation results in negative regulatory signals that induce apoptosis and inhibit tumor antigen-specific T cells allowing immune evasion of the tumor.The aim of this aim is to measure the expression level of PD-L1 on oral tissue samples from DLBCL patients using immunohistochemistry.

MATERIALS AND METHODS

 This current study was performed at the Faculty of Dentistry, Tanta University, Egypt. Ethical approval was conducted from Faculty of Dentistry, Tanta University. Tissue samples were collected from 13 patients diagnosed with oral extranodal DLBCL) nongerminal center B cell like subtype. Both hematoxylin and eosin and immunohistochemical staining (The avidin-biotin-complex procedure) was performed with anti-PD-L1 antibody (clone number: 28-8, Abcam, Cambridge, Massachusetts, United States).Cytoplasmic and/or membranous positive intensity was graded as follows: very mild staining, mild staining, moderate staining, and intense staining using Image J, 1.41a (National Institutes of Health, United States) image analysis software. The mean area fraction of the stained cells was calculated by counting immunostained cells in three fields of each case by two pathologists. Data was entered in SPSS program for analysis.

RESULTS

 PD-L1 was overexpressed on tumor cells of oral extranodal DLBCL than control cells from lesion free areas of oral tissues of the same patient.

Origin and Therapies of Osteosarcoma

Simple Summary

Osteosarcoma is the most common malignant bone tumor in children, with a 5-year survival rate ranging from 70% to 20% depending on the aggressiveness of the disease. The current treatments have not evolved over the past four decades due in part to the genetic complexity of the disease and its heterogeneity. This review will summarize the current knowledge of OS origin, diagnosis and therapies.

Abstract

Osteosarcoma (OS) is the most frequent primary bone tumor, mainly affecting children and young adults. Despite therapeutic advances, the 5-year survival rate is 70% but drastically decreases to 20–30% for poor responders to therapies or for patients with metastasis. No real evolution of the survival rates has been observed for four decades, explained by poor knowledge of the origin, difficulties related to diagnosis and the lack of targeted therapies for this pediatric tumor. This review will describe a non-exhaustive overview of osteosarcoma disease from a clinical and biological point of view, describing the origin, diagnosis and therapies.

Immune contexture of paediatric cancers

BACKGROUND

The clinical development of immune checkpoint-targeted immunotherapies has been disappointing so far in paediatric solid tumours. However, as opposed to adults, very little is known about the immune contexture of paediatric malignancies.

METHODS

We investigated by gene expression and immunohistochemistry (IHC) the immune microenvironment of five major paediatric cancers: Ewing sarcoma (ES), osteosarcoma (OS), rhabdomyosarcoma (RMS), medulloblastoma (MB) and neuroblastoma (NB; 20 cases each; n = 100 samples total), and correlated them with overall survival.

RESULTS

NB and RMS tumours had high immune cell gene expression values and high T-cell counts but were low for antigen processing cell (APC) genes. OS and ES tumours showed low levels of T-cells but the highest levels of APC genes. OS had the highest levels of macrophages (CSF1R, CD163 and CD68), whereas ES had the lowest. MB appeared as immune deserts. Tregs (FOXP3 staining) were higher in both RMS and OS. Most tumours scored negative for PD-L1 in tumour and immune cells, with only 11 of 100 samples positive for PD-L1 staining. PD-L1 and OX40 levels were generally low across all five indications. Interestingly, NB had comparable levels of CD8 by IHC and by gene expression to adult tumours. However, by gene expression, these tumours were low for T-cell cytotoxic molecules GZMB, GZMA and PRF1. Surprisingly, the lower the level of tumour infiltrative CD8 T-cells, the better the prognosis was in NB, RMS and ES. Gene expression analyses showed that MYCN-amplified NB have higher amounts of immune suppressive cells such as macrophages, myeloid-derived suppressor cells and Tregs, whereas the non-MYCN-amplified tumours were more infiltrated and had higher expression levels of Teff.

CONCLUSIONS

Our results describe the quality and quantity of immune cells across five major paediatric cancers and provide some key features differentiating these tumours from adult tumour types. These findings explain why anti-PD(L)1 might not have had single agent success in paediatric cancers. These results provides the rationale for the development of biologically stratified and personalised immunotherapy strategies in children with relapsing/refractory cancers.

Case Report: Two Cases of Soft-Tissue Sarcomas: High TMB as a Potential Predictive Biomarker for Anlotinib Combined With Toripalimab Therapy

Soft-tissue sarcomas (STS), with over 100 different histologic subtypes, are rare tumors that account for 1% of all adult malignancies. Immune checkpoint inhibitors (ICIs) display certain benefits in some subtypes, especially in undifferentiated pleomorphic sarcoma (UPS), alveolar soft part sarcoma (ASPS), and leiomyosarcoma (LMS). However, efficacy is difficult to predict. High tumor mutational burden (TMB-H) and programmed death-ligand 1 (PD-L1) expression are the strongest features associated with the efficacy of immunotherapy, although they are rarely found in STS patients. Until now, whether or not PD-L1 expression and TMB are related to the efficacy of immunotherapy has not been determined. In this study, we report data obtained from two STS patients, one ASPS and one UPS with a high TMB, that benefited from anlotinib combined with toripalimab following resistance to anlotinib monotherapy. A 26 year-old female patient was diagnosed with ASPS. PD-L1 was negative. Next generation sequencing (NSG) revealed ASPSCR1-TFE3 fusion and TMB-H. Following eight months of anlotinib monotherapy, the patient’s disease progressed but continued to benefit from subsequent use of anlotinib combined with toripalimab for 19 months. Another 63 year-old male patient was diagnosed with UPS. PD-L1 was positive and NGS revealed TMB-H. Following 19 months of anlotinib monotherapy, the patient’s disease progressed but continued to benefit from subsequent use of anlotinib combined with toripalimab. DFS is 23 months to follow-up time. The results presented are the first to report the relationship between TMB and the efficacy of immunotherapy in STS. Based on our results, we hypothesis that anlotinib combined with toripalimab is effective for the treatment of some advanced ASPS or UPS. TMB may be a potential predictive biomarker for ICI treatment and deserves additional study.

Evaluation of PD-L1 Expression in Undifferentiated Pleomorphic Sarcomas, Liposarcomas and Chondrosarcomas

Immune checkpoint inhibitors (ICIs) such as PD1/PD-L1 blockers are an established treatment for many solid cancers. There are currently no approved ICIs for sarcomas, but satisfactory results have been seen in some patients with disseminated disease in certain histological types. Most studies on PD-L1 in sarcoma have used small specimens and there are no clear cutoff values for scoring. We investigated PD-L1 immunoreactivity in high-grade chondrosarcomas (CS), abdominal liposarcoma (LS) and undifferentiated pleomorphic sarcomas (UPS). In total, 230 tumors were stained with SP142 and SP263 assays and evaluated by two clinical pathologists. Immunoreactivity in tumor and immune cells was correlated with clinical outcome. Overall, ≥1% PD-L1 immunoreactivity in tumor cells was found in 11 CS, 26 LS and 59 UPS (SP142 assay) and in 10 CS, 26 LS and 77 UPS (SP263 assay). Most tumors exhibited ≤10% PD-L1 immunoreactivity, but a subset across all three subtypes had >50%. Kaplan–Meier survival analysis showed no significant difference in metastasis-free or overall survival in relation to PD-L1 immunoreactivity in tumor or immune cells for any subtype. As there is a lack of clinical data regarding PD-L1/PD-1 status and therapy response, it is not currently possible to establish clear cutoff values. Patients with high (>50%) PD-L1 immunoreactivity in tumor cells (TC) with the SP263 assay would be a logical group to investigate for potentially beneficial PD1/PD-L1-targeted treatment.

The COX-2-PGE2 pathway promotes tumor evasion in colorectal adenomas

The mechanisms underlying the regulation of a checkpoint receptor, PD-1, in tumor-infiltrating immune cells during the development of colorectal cancer (CRC) are not fully understood. Here we demonstrate that COX-2-derived PGE2, an inflammatory mediator and tumor promoter, induces PD-1 expression by enhancing NF-κB's binding to the PD-1 promoter via an EP4-PI3K-Akt signaling pathway in both CD8+ T cells and macrophages. Moreover, PGE2 suppresses CD8+ T cell proliferation and cytotoxicity against tumor cells and impairs macrophage phagocytosis of cancer cells via an EP4-PI3K-Akt-NF-κB-PD-1 signaling pathway. In contrast, inhibiting the COX-2-PGE2-EP4 pathway increases intestinal CD8+ T cell activation and proliferation and enhances intestinal macrophage phagocytosis of carcinoma cells accompanied by reduction of PD-1 expression in intestinal CD8+ T cells and macrophages in ApcMin/+ mice. PD-1 expression correlates well with COX-2 levels in human CRC specimens. Both elevated PD-1 and COX-2 are associated with poorer overall survival in colorectal cancer patients. Our results uncover a novel role of PGE2 in tumor immune evasion. They may provide the rationale for developing new therapeutic approaches to subvert this process by targeting immune checkpoint pathways using EP4 antagonists. In addition, our findings reveal a novel mechanism explaining how NSAIDs reduce colorectal cancer risk by suppressing tumor immune evasion.

Analysis of PD-1, PD-L1, and T-cell infiltration in angiosarcoma pathogenetic subgroups

Angiosarcoma (AS) is a rare malignancy with a poor prognosis. It can develop spontaneously or due to previous radiotherapy (RT), ultraviolet (UV) radiation, or lymphoedema (Stewart Treves AS). Novel therapeutic approaches are needed, but progress is hindered because of the heterogeneity and rarity of AS. In order to explore the potential of immune checkpoint inhibition (ICI), we investigated the protein expression of programmed cell death 1 (PD-1), programmed death-ligand 1 (PD-L1), and CD8 + T cells in 165 AS cases in relation to AS subgroups based on clinical classification and in relation to whole-genome methylation profiling based clusters (A1, A2, B1, B2). High PD-L1 and PD-1 expression were predominantly shown in UV-associated, visceral, and soft tissue AS. RT-associated AS showed predominantly high PD-1 expression. CD8 + T cell infiltration was present in the majority of AS samples. Within the UV-associated AS, two different clusters can be distinguished by DNA methylation profiling. Cases in cluster A1 showed higher PD-1 (p = 0.015), PD-L1 (p = 0.015), and CD8 + T cells (p = 0.008) compared to those in cluster B2, suggesting that these UV-AS tumors are more immunogenic than B2 tumors showing a difference even within one subgroup. In soft tissue AS, combined PD-1 and PD-L1 expression showed a trend toward poor survival (p = 0.051), whereas in UV-associated AS, PD-1 expression correlated with better survival (p = 0.035). In conclusion, we show the presence of PD-1, PD-L1, and CD8 + T cells in the majority of AS but reveal differences between and within AS subgroups, providing prognostic information and indicating to be predictive for ICI.

Epigenetics of Cutaneous Sarcoma

Epigenetic changes influence various physiological and pathological conditions in the human body. Recent advances in epigenetic studies of the skin have led to an appreciation of the importance of epigenetic modifications in skin diseases. Cutaneous sarcomas are intractable skin cancers, and there are no curative therapeutic options for the advanced forms of cutaneous sarcomas. In this review, we discuss the detailed molecular effects of epigenetic modifications on skin sarcomas, such as dermatofibrosarcoma protuberans, angiosarcoma, Kaposi's sarcoma, leiomyosarcoma, and liposarcoma. We also discuss the application of epigenetic-targeted therapy for skin sarcomas.

Improving Immunotherapy Efficacy in Soft-Tissue Sarcomas: A Biomarker Driven and Histotype Tailored Review

Anti-PD-(L)1 therapies yield a disappointing response rate of 15% across soft-tissue sarcomas, even if some subtypes benefit more than others. The proportions of TAMs and TILs in their tumor microenvironment are variable, and this heterogeneity correlates to histotype. Tumors with a richer CD8+ T cell, M1 macrophage, and CD20+ cells infiltrate have a better prognosis than those infiltrated by M0/M2 macrophages and a high immune checkpoint protein expression. PD-L1 and CD8+ infiltrate seem correlated to response to immune checkpoint inhibitors (ICI), but tertiary lymphoid structures have the best predictive value and have been validated prospectively. Trials for combination therapies are ongoing and focus on the association of ICI with chemotherapy, achieving encouraging results especially with pembrolizumab and doxorubicin at an early stage, or ICI with antiangiogenics. A synergy with oncolytic viruses is seen and intratumoral talimogene laherpavec yields an impressive 35% ORR when associated to pembrolizumab. Adoptive cellular therapies are also of great interest in tumors with a high expression of cancer-testis antigens (CTA), such as synovial sarcomas or myxoid round cell liposarcomas with an ORR ranging from 20 to 50%. It seems crucial to adapt the design of clinical trials to histology. Leiomyosarcomas are characterized by complex genomics but are poorly infiltrated by immune cells and do not benefit from ICI. They should be tested with PIK3CA/AKT inhibition, IDO blockade, or treatments aiming at increasing antigenicity (radiotherapy, PARP inhibitors). DDLPS are more infiltrated and have higher PD-L1 expression, but responses to ICI remain variable across clinical studies. Combinations with MDM2 antagonists or CDK4/6 inhibitors may improve responses for DDLPS. UPS harbor the highest copy number alterations (CNA) and mutation rates, with a rich immune infiltrate containing TLS. They have a promising 15-40% ORR to ICI. Trials for ICB should focus on immune-high UPS. Association of ICI with FGFR inhibitors warrants further exploration in the immune-low group of UPS. Finally translocation-related sarcomas are heterogeneous, and although synovial sarcomas a poorly infiltrated and have a poor response rate to ICI, ASPS largely benefit from ICB monotherapy or its association with antiangiogenics agents. Targeting specific neoantigens through vaccine or adoptive cellular therapies is probably the most promising approach in synovial sarcomas.

PD1/PDL1 expression is associated with increased TIM3 expression and tumor-infiltrating T lymphocytes in fibroblastic tumors

PURPOSE

The combined therapy of inhibiting T cell immunoglobulin domain and mucin domain 3 (TIM3) and programmed cell death 1/programmed death-ligand 1 (PD1/PDL1) has shown encouraging therapeutic effects in some solid tumors. However, the expression of PD1/PDL1 and TIM3 in fibroblastic tumors is ill defined, which has limited the application of these immune checkpoint inhibitors in such tumors.

METHODS

Immunostaining of 68 tissue microarray cores of fibroblastic tumors, including intermediate dermatofibrosarcoma protuberans and malignant myxofibrosarcoma and adult-type fibrosarcoma, was used to determine the expression of PD1, PDL1 and TIM3, as well as their relationship with the accumulation of tumor-infiltrating T lymphocytes (TILs).

RESULTS

Both PD1 and PDL1 expression was only observed in a small proportion of fibroblastic tumors, whereas TIM3 was expressed in almost all tumors. However, only the positive expression of PDL1 was related to tumors with high grade and staging. A considerable number of TILs, including CD4- and CD8A-positive T cells and a small group of FoxP3-positive T cells, was also observed in most tumors. The density of TIM3 was positively correlated with that of TILs. Furthermore, higher densities of TIM3, CD4, CD8A and FoxP3 were observed in PD1 and PDL1 double-positive fibroblastic tumors.

CONCLUSIONS

This study indicates that TILs with high expression of TIM3 may contribute to immunosuppression in the tumor microenvironment of fibroblastic tumors. Patients with fibroblastic tumors with high expression of PD1/PDL1 and TIM3 may therefore benefit from combination therapy with PD1/PDL1 and TIM3 inhibitors.

Case Report: Pulmonary Metastases From Epithelioid Sarcoma in Extremity Favourably Responding to Immunotherapy With Camrelizumab

Epithelioid sarcoma (ES) is a rare soft tissue sarcoma (STS), with limited therapies available for metastatic disease. Here, we describe a case of a 30-year-old male with ES of the left knee and underwent surgery and radiation therapy for the primary disease. After 2 years, he had local recurrence and underwent extensive resection surgery; however, adjuvant chemotherapies were delayed due to recurrent wound infection. Nine months after the second surgery, progressive disease was confirmed after detection of metastases to the lungs and inguinal lymph nodes. Amputation was performed for the local recurrence, followed by inguinal lymph nodes dissection. Pazopanib was transiently administered but discontinued as a result of wound dehiscence. The tumour specimens were detected with unexpected high level of PD-L1 expression and tumoural infiltrating lymphocytes. Subsequently, he received camrelizumab 2.0 mg/kg every 21 days for 18 cycles with rapid remission of the pulmonary metastases. This promising response to camrelizumab indicates that immunotherapies may be an alternative choice for patients with metastatic ES in lung based on analysing the tumour immune microenvironment.

PD-L1 expression in sarcomas: An immunohistochemical study and review of the literature

BACKGROUND

Immunotherapy is increasingly used for treatment of metastatic melanoma and carcinomas. PD-1 (programmed death 1) and its associated ligand (PD-L1) inhibits the activation of T-lymphocytes. This inhibition can be impacted by a number of drugs. Response to these drugs is predicted by assessment of PD-L1 expression. PD-L1 expression varies between 19% and 92% in melanomas and carcinomas. PD-L1 expression is less well documented for sarcomas.

DESIGN

Fifty-six sarcomas of various histopathologic types were immunohistochemically stained (IHC) for PD-L1 using the antibody clone SP263 (Ventana, Tuscan, AZ). Membrane staining of tumor cells was quantitated as a percentage of total tumor cells. Sarcomas were judged as non-expressors (less than 1%) low-expressors (1 to 50%) and high expressors (greater than 50%). The percentage of each type of sarcoma judged as an expressor was determined.

RESULTS

Table 1 documents the percentage of each type of sarcoma expressing PD-L1. 14% of sarcomas expressed PD-L1. Percentage of sarcomas expressing PD-L1 varied significantly between types but the majority of sarcomas were non-expressors.

CONCLUSION

PD-L1 IHC expression is valuable in predicting response to immune-modulating drugs. Such therapies may be useful for treatment of metastatic sarcomas. Expression of PD-L1 in carcinomas and melanomas is variable ranging from 19% to 92%. In our study, a minority (14%) of sarcomas expressed PD-L1. Other studies have shown similar results with between 1.4 and 59% (average 24%) of sarcomas expressing PD-L1. Expression appears to be sarcoma type specific. These finding suggest that PD-L1 based therapy may be less useful in sarcomas than in other malignancies.

Immune infiltrates in patients with localised high-risk soft tissue sarcoma treated with neoadjuvant chemotherapy without or with regional hyperthermia: A translational research program of the EORTC 62961-ESHO 95 randomised clinical trial

BACKGROUND

The EORTC 62961-ESHO 95 randomised trial showed improved long-term survival of patients with high-risk soft-tissue sarcoma by adding regional hyperthermia to neoadjuvant chemotherapy. We hypothesised that immune infiltrate of patients treated with neoadjuvant therapy associate with clinical outcome.

METHODS

Tumour infiltrating lymphocytes (TILs) and CD8, FOXP3, PD-1, and PD-L1 were evaluated in sequential biopsies of patients after four cycles of therapy.

RESULTS

From a subgroup of 109 patients who had been randomised between July 1997 and November 2006 to neoadjuvant chemotherapy (53 patients) or neoadjuvant chemotherapy with regional hyperthermia (56 patients), 137 biopsies were obtained. TILs increased in paired second biopsies independent of treatment allocation (p < 0.001). FOXP3 regulatory T cells decreased (p = 0.002), and PD-L1 expression of tumours became undetectable. In the multivariate analysis, post-treatment high TILs correlated to LPFS (HR: 0.34; 95% CI 0.15-0.75; p = 0.008) and DFS (HR: 0.38; 95% CI 0.17-0.82; p = 0.015). In comparing post-treatment immune infiltrate between treatment arms, tumour response was associated with neoadjuvant chemotherapy with regional hyperthermia (p = 0.013) and high TILs (p = 0.064). High CD8 cell infiltration was associated with improved LPFS (HR: 0.27; 95% CI 0.09-0.79; Log-rank p = 0.011) and DFS (HR: 0.25; 95% CI 0.09-0.73; Log-rank p = 0.006). Improved survival at 10 years was associated with immune infiltrate after neoadjuvant chemotherapy with regional hyperthermia.

CONCLUSION

Preoperative therapy re-programs a non-inflamed tumour at baseline into an inflamed tumour. The post-treatment immune infiltrate became predictive for clinical outcomes. The combination with regional hyperthermia primes the tumour microenvironment, enabling enhanced anti-tumour immune activity in high-risk soft tissue sarcomas.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00003052.

Leiomyosarcoma: Does Location of Primary Help to Determine the Best Systemic Therapy Options?

OPINION STATEMENT

Management of leiomyosarcoma is based on the specifics of each individual case. Specifically, the location of the disease and whether the disease is metastatic or localized and if localized disease, whether the tumor is resectable or unresectable. In patients with recurrent or metastatic disease, factors such as disease-free interval and pattern of spread should be considered within the context of treatment planning. In general, patients with metastatic disease are typically treated with systemic chemotherapy with either an anthracycline-based regimen or gemcitabine-based regimen as first-line therapy. Additional systemic options include trabectedin, pazopanib, eribulin, and DTIC. Uterine LMS has been the most studied site-specific LMS with respect to systemic therapy. The increasing use of tumor genomics may ultimately define subsets which may benefit from tailored systemic therapies.

PD-1/PD-L1 Checkpoints and Resveratrol: A Controversial New Way for a Therapeutic Strategy

Simple Summary

Over the last decade, immunotherapies using antibodies targeting the programmed cell death 1 (PD-1) checkpoint or its ligand, programmed death ligand 1 (PD-L1), have emerged as promising therapeutic strategies against cancer. However, some current limitations include a relatively low rate of “responders”, the high cost of the treatment, and a rare risk of hyper-progression. Currently, the main challenge is, therefore, to improve these therapies, for instance, by using combined approaches. Here, we summarize the accumulating evidence that resveratrol (RSV) plays a role in the modulation of the PD-1/PD-L1 axis in cancer cells, suggesting the potential of therapeutic strategies combining RSV with PD-L1 or anti-PD-1 inhibitors. We then discuss the therapeutic potential of polyphenols such as RSV to be used in combination with PD-L1 or PD-1 inhibitors for the management of cancer patients.

Abstract

Immune checkpoints refer to a range of immunoregulatory molecules that modulate the immune response. For example, proteins expressed at the surface of T-cells (including PD-1 and CTLA-4) and their ligands (PD-L1 and B7-1/B7-2, respectively), expressed by cancer cells and antigen-presenting cells, are needed to prevent excessive immune responses. However, they dampen anti-tumor immunity by limiting T-cell activity, making them promising therapeutic targets in cancer. Although immunotherapies using checkpoint blocking/neutralizing antibodies targeting PD-L1 or PD-1 have proven their superiority over conventional chemotherapies or targeted therapies by enhancing T-cell-mediated anti-tumor immunity, some limitations have emerged. These include a relatively low rate of “responders” (<50%; irrespective of cancer type), the high cost of injections, and a rare risk of hyper-progression. For clinicians, the current challenge is thus to improve the existing therapies, potentially through combinatory approaches. Polyphenols such as resveratrol (RSV), a trihydroxystilbene found in various plants and an adjuvant in numerous nutraceuticals, have been proposed as potential therapeutic targets. Beyond its well-known pleiotropic effects, RSV affects PD-L1 and PD-1 expression as well as PD-L1 subcellular localization and post-translational modifications, which we review here. We also summarize the consequences of PD-1/PD-L1 signaling, the modalities of their blockade in the context of cancer, and the current status and limitations of these immunotherapies. Finally, we discuss their potential use in combination with chemotherapies, and, using RSV as a model, we propose polyphenols as adjuvants to enhance the efficacy of anti-PD-1/anti-PD-L1 immunotherapies.

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.

Linking Immunity with Genomics in Sarcomas: Is Genomic Complexity an Immunogenic Trigger?

Sarcomas comprise a collection of highly heterogeneous malignancies that can be grossly grouped in the categories of sarcomas with simple or complex genomes. Since the outcome for most sarcoma patients has barely improved in the last decades, there is an urgent need for improved therapies. Immunotherapy, and especially T cell checkpoint blockade, has recently been a game-changer in cancer therapy as it produced significant and durable treatment responses in several cancer types. Currently, only a small fraction of sarcoma patients benefit from immunotherapy, supposedly due to a general lack of somatically mutated antigens (neoantigens) and spontaneous T cell immunity in most cancers. However, genomic events resulting from chromosomal instability are frequent in sarcomas with complex genomes and could drive immunity in those tumors. Improving our understanding of the mechanisms that shape the immune landscape of sarcomas will be crucial to overcoming the current challenges of sarcoma immunotherapy. This review focuses on what is currently known about the tumor microenvironment in sarcomas and how this relates to their genomic features. Moreover, we discuss novel therapeutic strategies that leverage the tumor microenvironment to increase the clinical efficacy of immunotherapy, and which could provide new avenues for the treatment of sarcomas.

Tumor and Peripheral Immune Status in Soft Tissue Sarcoma: Implications for Immunotherapy

Simple Summary

Soft Tissue Sarcomas are a rare and heterogeneous group of tumors, which have a characteristic complexity, leading to a difficult diagnosis and a lack of response to treatment. The aim of this review is to summarize the role of immune cells, soluble plasmatic factors, immune checkpoints; and the expression of immune-related genes predicting survival, response to therapy, and potential immunotherapeutic agents or targets in Soft Tissue Sarcomas.

Abstract

Soft Tissue Sarcomas (STS) are a heterogeneous and rare group of tumors. Immune cells, soluble factors, and immune checkpoints are key elements of the complex tumor microenvironment. Monitoring these elements could be used to predict the outcome of the disease, the response to therapy, and lead to the development of new immunotherapeutic approaches. Tumor-infiltrating B cells, Natural Killer (NK) cells, tumor-associated neutrophils (TANs), and dendritic cells (DCs) were associated with a better outcome. On the contrary, tumor-associated macrophages (TAMs) were correlated with a poor outcome. The evaluation of peripheral blood immunological status in STS could also be important and is still underexplored. The increased lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR), higher levels of monocytic myeloid-derived suppressor cells (M-MDSCs), and Tim-3 positive CD8 T cells appear to be negative prognostic markers. Meanwhile, NKG2D-positive CD8 T cells were correlated with a better outcome. Some soluble factors, such as cytokines, chemokines, growth factors, and immune checkpoints were associated with the prognosis. Similarly, the expression of immune-related genes in STS was also reviewed. Despite these efforts, only very little is known, and much research is still needed to clarify the role of the immune system in STS.

Circulating PD-L1 is associated with T cell infiltration and predicts prognosis in patients with CRLM following hepatic resection

BACKGROUND

Exosomal PD-L1 (exoPD-L1) could induce immunosuppression functionally, thus impairing patients' survival in melanoma, NSCLC, and gastric cancer. However, no evidence demonstrates the feasibility of circulating exoPD-L1 and soluble PD-L1 (sPD-L1) as biomarkers for prognosis and early recurrence in colorectal liver metastasis (CRLM) patients following hepatectomy or their association with T cell infiltration at liver metastases.

METHODS

In cohort 1, exoPD-L1 and sPD-L1 were preoperatively tested using ELISA. CD3, CD8, granzyme B (GB) and PD1 expressed at liver metastases were evaluated using immunohistochemistry. In cohort 2, exoPD-L1 and sPD-L1 were detected at baseline, before hepatectomy, after hepatectomy, and after disease progression.

RESULTS

In cohort 1, higher preoperative exoPD-L1 or sPD-L1 significantly impaired RFS (exoPD-L1, P = 0.0043; sPD-L1, P = 0.0041) and OS (exoPD-L1, P = 0.0034; sPD-L1, P = 0.0061). Furthermore, preoperative exoPD-L1 was negatively correlated with CD3 + T-lymphocytes infiltrated at tumor center (CT), and GB and PD1 were expressed at tumor invasive margin (IM). Preoperative sPD-L1 was negatively correlated with CD3 + and CD8 + T-lymphocytes' infiltration at IM and CT, GB and PD1 expression at IM. In cohort 2, exoPD-L1 and sPD-L1 levels decreased following hepatectomy but increased when tumor progressed. Moreover, higher postoperative exoPD-L1 and sPD-L1 or a small reduction in exoPD-L1 and sPD-L1 levels after hepatectomy suggested higher early recurrence rate.

CONCLUSIONS

Both preoperative exoPD-L1 and sPD-L1 had promising prognostic values and were associated with T cell infiltration at liver metastases in CRLM patients following hepatectomy. Dynamically tracking exoPD-L1 and sPD-L1 levels could monitor disease status and detect early recurrence.

Clinicopathologic Characteristics and Clinical Outcome of Localized Liposarcoma: A Single Center Experience Over 25 Years and Evaluation of PD-L1 Expression

Purpose

For liposarcoma (LPS), clinical course and proper treatment strategies have not been well-established. Recently, immune-checkpoint inhibitors have shown potential efficacy in LPS. We aimed to describe the clinical course of LPS and evaluate the clinical impact of programmed death-ligand 1 (PD-L1).

Materials and Methods

We reviewed all consecutive patients (n=332) who underwent curative-intent surgery for localized LPS at Asan Medical Center between 1989 and 2017. PD-L1 testing was performed in well-differentiated and dedifferentiated LPS.

Results

The median age was 56 years with males comprising 60.8%. Abdomen-pelvis (47.6%) and well-differentiated (37.7%) were the most frequent primary site and histologic subtype, respectively. During a median follow-up of 81.2 months, recurrence was observed in 135 (40.7%), and 86.7% (117/135) were loco-regional. Well-differentiated subtype (hazard ratio [HR], 0.38), abdomen-pelvis origin (HR, 2.43), tumor size larger than 5 cm (HR, 1.83), positive resection margin (HR, 2.58), and postoperative radiotherapy (HR, 0.36) were significantly related with recurrence-free survival as well as visceral involvement (HR, 1.84) and multifocality (HR, 3.79) in abdomen-pelvis LPS. PD-L1 was positive in 31.5% (23/73) and 51.3% (39/76) of well-differentiated and dedifferentiated LPS, respectively, but had no impact on survival outcomes.

Conclusion

Clinical course of LPS was heterogeneous according to histology and anatomic location. Clear resection margin was important to lower recurrence and postoperative radiotherapy might have additional benefit. A decent portion of well-differentiated and dedifferentiated LPS were positive for PD-L1, but its prognostic role was unclear. Further research is needed to determine clinical implications of PD-L1, especially for advanced-stage LPS with unmet needs for effective systemic treatment.

Prevalence and Prognostic Implications of PD-L1 Expression in Soft Tissue Sarcomas

Background: PD-L1 expression differs from 19 to 92% in various cancer subtypes. Its expression carries a worse prognostic value in various malignancies and could also be used as a predictive marker for immune checkpoint inhibitor response. This study aimed to explore the prevalence of PD-L1 expression in soft tissue sarcomas and the correlation of PD-L1 expression with clinicopathological features.

Patients and Methods: The tissue samples of 50 patients with STS were tested for PD-L1 expression using immunohistochemistry (IHC). We followed a 6-step proportional scoring system. The patients were treated at Ain Shams University Hospital from 2011 to 2017. We also explored the correlation of PD-L1 expression with different clinical features of the patients. The chi-square test was used to calculate the differences among variables.

Results: Twelve cases (24%) showed positive PD-L1 expression with the highest prevalence in rhabdomyosarcoma and desmoid tumors (2/2 and 2/3 cases, respectively), followed by GIST in 2/4 cases and liposarcoma in 3/11 cases. Patients with positive PD-L1 expression showed a trend for worse survival, with a median overall survival of 11 months vs. 19 months for patients with negative PD-L1 expression (p-value = 0.1) and a mean PFS of 6 months vs. 11 months for patients with negative PD-L1 expression (p-value = 0.1). However, these findings did not reach statistical significance.

Conclusion: Although the results did not reach statistical significance due to the small number of cases, PD-L1 expression could represent a prognostic factor for poor outcome. Larger clinical trials are recommended for the validation of PD-L1 as a poor prognostic biomarker.