Immune checkpoint inhibitors in treatment of soft-tissue sarcoma: A systematic review and meta-analysis

Mapping the potential for anti-PD-1 therapy in advanced rare skin carcinomas

This review, focusing on cutaneous adnexal carcinomas, extramammary Paget disease (EMPD), cutaneous angiosarcomas (cAS) and Kaposi sarcoma (KS), summarizes their local recurrence and metastasis rates, tumor mutation burden (TMB), PD-L1 expression, and off-label treatment with systemic anti-PD-1 agents. PD-L1 expression and tumor mutation burden (TMB) were highly variable in adnexal carcinomas (also depending on the histological subtype), cAS and KS tumors, and some responses were noted even in lack of PD-L1 expression or in low-TMB tumors. There were encouraging best overall responses in patients with advanced rare skin carcinomas treated with anti-PD-1 agents in the literature, mostly after failure of other systemic treatments. We identified a total of 3 patients with sebaceous carcinoma (2 with complete response [CR], 1 with partial response [PR]), 5 with porocarcinoma (3 CR, 1 PR, 1 progression of disease [PD]), 2 with spiradenocarcinoma (1 PR, 1 PD), 1 with trichilemmal carcinoma with PR, 9 with EMPD (1 CR, 5 PR, 3 PD), 32 with cAS (5 CR, 18 PR, 9 PD), and 92 with KS (5 CR, 53 PR, 23 SD, 11 PD). However, a large variety of anti-PD-1 agents were used, in monotherapy or in combination with other systemic therapy, in a relatively small number of patients, limiting interpretations on their individual efficacy. The development of clinical guidelines on rare skin carcinomas may provide standardized guidance to physicians towards best care.

Liposarcoma: Novel Approaches to Systemic Therapy and Multidisciplinary Care

Retroperitoneal well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS) are rare tumors presenting as bulky abdominal tumors requiring multidisciplinary management in high-volume centers. Surgery is the mainstay of treatment through complete en bloc resection with the goal of achieving macroscopically complete resection, with a single specimen encompassing the tumor and involved contiguous organs. Preoperative radiation therapy is not standard of care and the role of preoperative chemotherapy is under investigation. If the tumor is not resectable or metastatic, the preferred treatment is doxorubicin-based chemotherapy in the case of DDLPS, whereas WDLPS are generally thought of as chemo-resistant.

Neoadjuvant Immunotherapy for Resectable Dedifferentiated Liposarcoma: A National Cohort Analysis

BACKGROUND

Neoadjuvant immunotherapy (NIT) with checkpoint blockade has been increasingly studied for soft tissue sarcomas, however, survival outcomes data are limited, and dedifferentiated liposarcoma (DDLPS) histology remains underrepresented in recent trial cohorts. We assessed the impact of NIT with or without radiation therapy (RT) on overall survival (OS) for resectable DDLPS.

METHODS

The National Cancer Database (NCDB) was used to identify patients diagnosed with nonmetastatic DDLPS who received NIT and underwent surgical resection between 2016 and 2022. Primary outcome was 5-year OS.

RESULTS

A total of 3414 patients with DDLPS met the inclusion criteria and NIT was administered to 31 (1%) patients. Factors associated with receipt of NIT were receipt of neoadjuvant RT (NRT, odds ratio [OR]: 5.75, p < 0.001) and male sex (OR: 3.33, p = 0.036). NIT was associated with a hazard ratio (HR) for mortality of 0.89 (p = 0.786). No difference was found in 5-year OS in the overall cohort (NIT 72% vs. 61% no NIT, p = 0.320) or in the propensity-matched cohort (68% vs. 65%, p = 0.848). Subanalysis between NIT with NRT versus NRT-only also did not find any significant difference in 5-year OS (88% vs. 59%, p = 0.331).

CONCLUSION

In this retrospective NCDB analysis of patients with resectable DDLPS, administration of NIT did not significantly affect OS.

The Impact of Resection Margins in Primary Resection of High-Grade Soft Tissue Sarcomas: How Far Is Far Enough?

Background/Objectives: The World Health Organization's (WHO) classification of tumors contains around 80 entities of soft tissue sarcomas (STSs). Currently, surgery is the standard treatment for patients with localized STS, but the adequacy of resection margins in soft tissue sarcomas (STSs) remains a topic of intense discussion. Methods: This single-center study retrospectively reviewed 203 patients with primary high-grade soft tissue sarcoma, including a follow-up period of at least 24 months. Patients with prior resection, secondary STS, metastasis at presentation, or those who required amputational surgery were excluded from the study. Patients were categorized based on their margin thickness: positive (n = 13, 6.4%), 0-1 mm (n = 67, 33.0%), 1-5 mm (n = 70, 34.5%), and >5 mm (n = 27, 13.3%). Results: A total of 64 out of 203 (31.5%) patients developed a local recurrence. The estimated 5-year local-recurrence-free survival (LRFS) was 11.5% (CI 4-25%) for positive margins, 58% (CI 51-64%) for margins 0-1 mm, 76% (CI 70-81%) for margins > 1-5 mm, and 93% (CI 88-98%) for margins > 5 mm. No local recurrences occurred in patients with margins > 5 mm and adjuvant radiotherapy. Margin status significantly influenced the development of distant metastasis and overall survival. Adjuvant radiotherapy improved both local control and overall survival. Conclusions: To minimize the risk of local recurrence (LR), a resection margin greater than 5 mm should be attained. When adjuvant radiotherapy is applied, the likelihood of LR decreases even more. In scenarios where preserving critical structures is essential, a resection margin of less than 5 mm can be acceptable for ensuring local control.

Which sarcoma requires PD1/PDL1 inhibitors, and what should be the best scheme? Present status and next steps

PURPOSE OF REVIEW

The introduction of immune checkpoint inhibitors (ICI) in advanced sarcoma has been largely disappointing due to their "cold" tumor microenvironment, characterized by low tumor mutational burden, scarce CD8+ T-cell infiltration, and minimal expression of PD-1/PD-L1. However, recent findings highlight several scenarios in which immune checkpoint blockade exhibits clinical efficacy.

RECENT FINDINGS

ICIs have shown durable efficacy in specific sarcoma subtypes, such as alveolar soft part sarcoma (ASPS), with objective response rates (ORR) exceeding 35% and 50%, in monotherapy or in combination, respectively. Doxorubicin-based regimens plus ICIs have yielded notorious and higher ORRs in the most common sarcoma subtypes, than historical chemotherapy data. Neoadjuvant radiation therapy combined with ICIs has significantly improved disease-free survival in localized selected soft tissue sarcomas.

SUMMARY

Immunotherapy targeting immune checkpoints in sarcomas is evolving, with recent findings highlighting its potential. Single-arm trials underscore the efficacy of ICIs in rare sarcomas, exemplified by the FDA approval of atezolizumab for ASPS. Combination strategies are proving more effective than chemotherapy alone, with ongoing comparative studies assessing chemo-immunotherapy in both metastatic and localized sarcomas. Advances in predictive biomarkers could expand the clinical use of ICIs.

Expression of Cancer-Testis Antigens MAGE-A1, MAGE-A4, NY-ESO-1 and PRAME in Bone and Soft Tissue Sarcomas: The Experience From a Single Center in China

OBJECTIVE

Sarcomas are a heterogeneous group of malignancies, low disease-control levels and the limited durability of responses have prompted the exploration of various novel immunotherapeutic approaches. To preliminarily explore the feasibility of cancer vaccines based on cancer testis antigen in the immunotherapy of sarcomas, we investigate the expression of Cancer/Testis Antigens (CTA) MAGE-A4, PRAME, MAGE-A1, KK-LC-1, and NY-ESO-1 in bone and soft tissue sarcomas, with the aim of assessing their potential for use in sarcoma immunotherapy and determining their expression levels in different subtypes.

METHODS AND RESULTS

We employed immunohistochemistry and multiplex immunostaining microarrays (MI chips) to assess the expression of MAGE-A4, PRAME, MAGE-A1, KK-LC-1, and NY-ESO-1 in 21 cases of undifferentiated pleomorphic sarcoma (UPS), 26 cases of smooth muscle sarcoma, 28 cases of liposarcoma, 40 cases of osteosarcoma (OS), and 13 cases of chondrosarcoma. MAGE-A1 showed the highest expression in osteosarcoma (32.50%), while it was lower in liposarcoma and undifferentiated pleomorphic sarcoma (10.71% and 10.00%) and undetectable in chondrosarcoma. MAGE-A4 expression was elevated in osteosarcoma and undifferentiated pleomorphic sarcoma (40.00% and 33.00%), but lower in liposarcoma and smooth muscle sarcoma (17.00% and 33.00%). NY-ESO-1 expression was relatively low across all sarcoma subtypes. PRAME expression was highest in undifferentiated pleomorphic sarcoma (47.62%) and low in chondrosarcoma (7.69%). None of the sarcomas expressed KK-LC-1. Additionally, while there was no statistically significant correlation between CTA expression and patient age or gender, some differences related to age and gender were observed.

CONCLUSIONS

CTA expression in bone and soft tissue sarcomas was correlated with both CTA type and sarcoma subtype, showing relatively high levels of expression in undifferentiated pleomorphic sarcoma (UPS) and osteosarcoma (OS). The poly-expression of MAGE-A4, PRAME, and MAGE-A1 across all subtypes suggests that these antigens may serve as potential targets for sarcoma-specific immunotherapy.

The outcomes and treatment strategies in metastatic soft tissue sarcoma treated with immunotherapy-based therapy: a three-center study

Background

Preclinical studies showed that cytotoxic agents and antiangiogenic agents had regulatory effects in the tumor immune microenvironment of soft tissue sarcoma (STS), and then enhance the antitumor effect of immunotherapy. This study was to investigate the efficacy and safety of immunotherapy-based therapy in metastatic STS.

Methods

We conducted a retrospective analysis in three centers where some patients received immunotherapy-based therapy consisting of immunotherapy alone or in combination with systemic agents (cytotoxic agents and/or antiangiogenic agents). The primary endpoints were median progression-free survival (mPFS) and median overall survival (mOS), and Kaplan-Meier method was used to compare survival.

Results

A total of 79 patients were included in this study. With the median follow-up of 14.2 months, the mPFS and mOS was 7.5 months and 19.5 months, respectively. The PFS (P < 0.01) and OS (P < 0.01) were significantly better in the alveolar soft part sarcoma (ASPS) group compared to the non-ASPS group. Patients who treated in ≤2 lines had longer PFS (P < 0.01) and OS (P < 0.01) compared to those in subsequent lines. Further analysis was performed according to histopathological types, in patients with ASPS, the combination of immunotherapy-based therapy resulted in a longer PFS (P < 0.01) compared to immunotherapy in monotherapy. Similarly, the patients treated in ≤2 lines had longer PFS (P=0.03) and OS (P < 0.01) compared to in subsequent lines. In patients with non-ASPS, patients with potentially sensitive sarcomas (undifferentiated pleomorphic sarcoma, dedifferentiated liposarcoma, myxofibrosarcoma, and angiosarcoma) had a longer PFS (P = 0.02) and OS (P = 0.03) compared to other subtypes. The OS (P = 0.03) for patients with potentially sensitive sarcomas treated in ≤2 lines showed a long trend compared to subsequent lines. Most adverse events reported were mild and tolerable.

Conclusions

The immunotherapy-based therapy showed promising activity in survival, especially in certain histological subtypes (undifferentiated pleomorphic sarcoma, dedifferentiated liposarcoma, myxofibrosarcoma, and angiosarcoma), as well as in combination treatment and in early lines. Prospective researches are needed to confirm the potential benefits.

Efficacy of immune checkpoint inhibitors in the treatment of soft tissue sarcoma: A systematic review and meta-analysis of clinical trials

BACKGROUND

Soft tissue sarcomas (STS) are a heterogeneous group of tumors with diverse clinical and molecular characteristics, characterized by limited treatment options and poor prognosis. Immune checkpoint inhibitors (ICIs) have emerged as promising therapies for STS, yet comprehensive evaluations of their efficacy, especially in combination with other treatments, are scarce.

METHODS

We conducted a systematic review and meta-analysis of clinical trials on ICIs in STS treatment, sourced from PubMed, Embase, and the Cochrane Central Register of Controlled Trials up to May 31, 2024. The studies included both monotherapy and combination therapies with ICIs. We assessed the methodological quality using the Cochrane Risk of Bias 2 tool and the Methodological Index for Non-Randomized Studies. Data synthesis involved random-effects meta-analysis to determine pooled proportions and 95% confidence intervals (CIs) for objective response rates (ORR), disease control rates (DCR), and high-grade treatment-related adverse events (TRAEs).

RESULTS

The analysis included 38 studies with 1349 patients covering 24 STS subtypes. The overall ORR was 16% (95% CI 0.12-0.21), DCR was 64% (95% CI 0.57-0.70), and the rate of Grade 3-5 TRAEs was 19% (95% CI 0.13-0.27). Treatments combining ICIs with tyrosine kinase inhibitors (TKIs) showed the highest efficacy (ORR 28%, 95% CI 0.18-0.40), albeit with increased adverse events. ORRs in first-line treatments were substantially higher (28%) compared to second-line treatments or beyond (11%). Subtypes like alveolar soft part sarcoma (ASPS), angiosarcoma (AS), and epithelioid sarcoma (ES) exhibited favorable responses exceeding 30%.

CONCLUSIONS

This systematic review and meta-analysis indicate that ICIs, particularly when combined with TKIs, provide substantial therapeutic benefits in treating STS, significantly enhancing response rates in specific subtypes such as ASPS and AS. The results underscore the transformative potential of ICIs in STS treatment strategies. However, the variability across subtypes and treatment lines emphasizes the need for further randomized controlled trials to refine and personalize therapeutic approaches, ensuring optimal outcomes for patients with these diverse malignancies.

Histologic and Immunologic Factors Associated with Response to Immune Checkpoint Inhibitors in Advanced Sarcoma

PURPOSE

To characterize factors associated with response to immune checkpoint inhibitors (ICI) in advanced sarcoma.

EXPERIMENTAL DESIGN

This is a retrospective study with a cohort of 216 patients with advanced sarcoma treated with ICI between 2016 and 2023 at Stanford Health Care. Overall survival, progression-free survival (PFS), objective response rates (ORR) per RECIST criteria, and reason for ICI discontinuation were analyzed across histologic subtypes, ICI regimens, tumor mutational burden, and PD-L1 expression.

RESULTS

The overall ORR in the cohort was 16.7%. The histologic subtypes with the highest ORR were Kaposi sarcoma (KS, 66.7%), alveolar soft part sarcoma (ASPS, 50%), angiosarcoma (33.3%), myxofibrosarcoma (MFS, 28.6%), and undifferentiated pleomorphic sarcoma (UPS, 27.8%). The subtypes with the lowest ORR were osteosarcoma (0%), synovial sarcoma (0%), and liposarcoma (3.7%). The subtypes with the highest median PFS were KS (median not reached), ASPS (median not reached), MFS (27.4 months), and UPS (11.3 months). The ORR for sarcomas with PD-L1 ≥ 1% was 27.8% (P = 0.02), whereas the ORR for sarcomas with tumor mutational burden ≥10 mutations per megabase of DNA was 28.6% (P = 0.20).

CONCLUSIONS

ORR and PFS were highly variable across sarcoma histologic subtypes. In this large analysis, KS, ASPS, angiosarcoma, MFS, and UPS demonstrated the highest ORR and longest PFS while osteosarcoma, synovial sarcoma, and liposarcoma had the lowest ORR and shortest PFS. PD-L1 expression was also associated with increased ORR. Our findings provide further insight into understanding the sarcoma histologic and immunologic factors that correspond with response to ICI.

Immune checkpoint inhibitors and endocrinopathies in pediatric brain tumor patients

OBJECTIVES

Immune checkpoint inhibitors (ICIs) are emerging treatment options for children with brain tumors, who are already at risk for developing endocrinopathies due to tumor location and treatment. Endocrine ICI-related adverse effects (irAEs) are common in adults but poorly characterized in the pediatric population. The aims of this study were to determine in pediatric brain tumor patients in a single institution (1) if endocrine surveillance took place before and after ICIs were initiated, and (2) the occurrence of endocrine irAEs.

METHODS

This is a retrospective chart review of 22 pediatric brain tumor patients treated with ICIs at Children's Hospital Los Angeles between 2010 and 2022. We analyzed endocrine laboratory results, patient demographics, and treatment course.

RESULTS

Most patients (82 %) received surveillance in at least one endocrine system before ICI treatment - all had thyroid function tested (100 %) whereas non-thyroid endocrine functions were seldomly assessed (6-22 %). Only those patients with surveillance prior to treatment had ongoing surveillance after ICI initiation - 100 % for thyroid function and 17-39 % for other endocrine systems. Hypothyroidism was the only endocrine problem diagnosed after ICI initiation, in two patients (9 %). Of note, most patients (68 %) expired during or shortly after ICI treatment.

CONCLUSIONS

This is one of the first institutional surveys of pediatric ICIs in a high-volume pediatric brain tumor center. Thyroid surveillance commonly occurred in pediatric patients, revealing diagnoses of hypothyroidism, which is consistent with adult data. However, little information is available for non-thyroid endocrine conditions, reflecting the need for comprehensive and systematic endocrine surveillance.

"From Drowning to Treading Water": Adolescents and Young Adults Living with Incurable and Indolent Metastatic Soft Tissue Sarcoma for More than Two Years

INTRODUCTION

Adolescent/young adult (AYA) patients with metastatic soft tissue sarcoma (STS) typically face a dismal prognosis. However, a subset of patients with incurable disease lives beyond two years. Due to the rarity of diagnoses and inherent heterogeneity within this population, a paucity of data exists regarding the experiences of AYAs with an indolent course (and how to best capture these experiences). With increasing biological insight and clinical experience, including the use of targeted or immune therapies, it is anticipated that more such patients will experience prolonged survival. Our pilot study aimed to describe the clinical characteristics and illness experiences of AYAs with incurable yet indolent metastatic STS who were living two years after their diagnoses. Our exploratory aim was to generate a conceptual framework that could subsequently be tested in a multi-center study with a larger cohort of patients.

MATERIALS AND METHODS

Patients with metastatic incurable STS, aged 15-39 years at diagnosis, and at least two years from diagnosis, were eligible. Patients were recruited over a two-year period at a quaternary children's hospital with a comprehensive AYA oncology program. Participants completed a demographic form and PROMIS short form questionnaires for seven domains and answered an open-ended question. Responses to open-ended questions were coded independently by two authors and utilized to generate themes. Clinical variables were collected from medical records.

RESULTS

Five patients completed questionnaires. Mean age was 29.4 years (18.5-39.8 years) at diagnosis and 34 years (23.2-45.7 years) at study. Three patients were female; two were male; four were White; and one was Black/African American. Diagnoses included ASPSCR1::TFE3 alveolar soft part sarcoma; WWTR1::CAMTA1 epithelioid hemangioendothelioma; INI-1 deficient epithelioid sarcoma; EWSR1::NR4A3 extra-skeletal myxoid chondrosarcoma; and low-grade ARHGAP23::FER spindle cell malignancy, a novel fusion-driven sarcoma. Mean time since diagnosis was 4.5 years (2.6-6 years), and mean treatment duration was 4.2 years (1.5-6 years). On average, patients received 4.8 lines (range 2-8 lines) of antineoplastic therapy. All patients received at least one targeted therapy or immune checkpoint inhibitor. Patients reported increased fatigue and anxiety and decreased physical function compared to the standardized US reference population. Themes emerging from qualitative responses included managing physical symptoms, navigating feelings of guilt and inadequacy, self-reflection generating gratitude, and changing illness experiences over time.

CONCLUSIONS

AYA patients living with incurable metastatic soft tissue sarcoma for more than two years were treated with multiple lines of antineoplastic therapy longitudinally. PROMIS data identified fatigue, anxiety, and decreased physical function within this population. Exploratory thematic analysis of qualitative responses generated concepts that could be further tested in an expanded cohort of patients.

Navigating the landscape of neoadjuvant immunotherapy for NSCLC: progress and controversies

Recently, attention has increasingly centered on non-small-cell lung cancer (NSCLC) with immune checkpoint inhibitors application. Numerous clinical studies have underscored the potential of immunotherapy in treating resectable NSCLC, highlighting its role in improving patient outcomes. However, despite these promising results, there is ongoing debate regarding the efficacy of immunological combination therapy strategies, the prevalence of treatment-related side effects, the identification of predictive biomarkers, and various other challenges within the neoadjuvant context. Careful consideration is essential to maximize the benefits of immunotherapy for patients with resectable NSCLC. This article offers a detailed overview of recent advancements in neoadjuvant immunotherapy for resectable NSCLC. By examining these developments, we aim to provide new perspectives and valuable insights into the benefits and challenges of applying neoadjuvant immunotherapy in clinical settings.

Association of Lung Immune Prognostic Index (LIPI) with Disease Control Rate and Progression-Free Survival in Patients with Soft-Tissue Sarcoma Treated with Immunotherapy in Early-Phase Trials

BACKGROUND

The efficacy of immunotherapies in soft-tissue sarcomas (STSs) is limited, and biomarkers of response are lacking. The lung immune prognostic index (LIPI) is a prognostic biomarker used with immunotherapy across cancer types. This study investigates the association of LIPI with the disease control rate (DCR) and progression-free survival (PFS) in patients with STS treated with immunotherapy versus other therapies in early-phase trials.

METHODS

This post hoc analysis was conducted with patients with STS from Gustave Roussy and Centre Léon Bérard between January 2012 and June 2021. The LIPI was calculated based on a derived neutrophil-to-lymphocyte ratio > 3 and elevated lactate dehydrogenase. Patients were categorized based on treatment (immunotherapy or other) and LIPI (good, intermediate, or poor). DCR was defined as the sum of stable disease and complete and partial response.

RESULTS

A total of 82 patients were enrolled in immunotherapy trials and 126 in the other therapy trials. In the immunotherapy group, DCR was higher in patients with good LIPI (76%; n = 23/30) compared with the intermediate (50%; n = 13/26) and poor LIPI groups (8%; n = 1/12; p < 0.001). The other-therapy group did not show significant differences in DCR by LIPI: DCR was 70% (n = 48/69), 70% (n = 21/30), and 60% (n = 6/10) in patients with good, intermediate, and poor LIPI, respectively (p = 0.86). In multivariate analyses, LIPI was independently associated with PFS in the immunotherapy group (hazard ratio = 5.97, p = 0.0001) and not in the control group (p = 0.71).

CONCLUSIONS

LIPI is a significant independent prognostic marker for DCR in patients with STS treated with immunotherapy. In early-phase trials, LIPI could be used as a screening tool for stratification at inclusion. High neutrophil levels, which correlate with a poorer LIPI score, are likely associated with immunotherapy resistance. This relationship could explain the statistical impact of poor LIPI in the immunotherapy group.

Multidimensional Immunotyping of Human NF1-Associated Peripheral Nerve Sheath Tumors Uncovers Tumor-Associated Macrophages as Key Drivers of Immune Evasion in the Tumor Microenvironment

PURPOSE

Malignant peripheral nerve sheath tumors (MPNST) are aggressive soft-tissue sarcomas and the leading cause of mortality in individuals with neurofibromatosis type 1 (NF1). Despite many clinical trials, outcomes for patients with MPNST have remained stagnant, and most succumb to their disease; thus, novel therapeutic approaches are needed. A better understanding of the MPNST immune ecosystem will aid in the development of strategies to activate the immune system against the tumor. In this study, we profile the tumor immune microenvironment (TIME) in NF1-associated peripheral nerve sheath tumors (PNST) to discover insights on the role played by tumor-infiltrating immune cells in malignant transformation.

EXPERIMENTAL DESIGN

Using fresh and formalin-fixed paraffin-embedded tissue from patients diagnosed with NF1-PNST, we dissected the TIME through IHC, multiparameter flow cytometry, and comparative transcriptomic studies.

RESULTS

Immunophenotyping confirmed increased immune cell infiltration during malignant progression, with a predominance of infiltrating myeloid cells, particularly CD163+ tumor-associated macrophages (TAM). The T cells within MPNST exhibited signs of tumor activation, characterized by high programmed cell death 1 expression. Additionally, MPNST specimens demonstrated elevated levels of immunosuppressive TAM, with heightened PD-L1 expression. The proportion of CD163+ myeloid cells within the TIME correlated with poorer progression-free survival. Notably, loss of H3K27 trimethylation correlated with low immune cell infiltration in MPNST.

CONCLUSIONS

Malignant transformation of NF1-PNST is characterized by an immunosuppressive microenvironment comprising TAM with high expression of PD-L1, which is associated with inferior outcomes. These findings suggest the clinical potential of immune-modulating therapeutics that can unleash an antitumor immune response.

Targeted immunotherapy and nanomedicine for rhabdomyosarcoma: The way of the future

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. Histology separates two main subtypes: embryonal RMS (eRMS; 60%-70%) and alveolar RMS (aRMS; 20%-30%). The aggressive aRMS carry one of two characteristic chromosomal translocations that result in the expression of a PAX3::FOXO1 or PAX7::FOXO1 fusion transcription factor; therefore, aRMS are now classified as fusion-positive (FP) RMS. Embryonal RMS have a better prognosis and are clinically indistinguishable from fusion-negative (FN) RMS. Next to histology and molecular characteristics, RMS risk groupings are now available defining low risk tumors with excellent outcomes and advanced stage disease with poor prognosis, with an overall survival of about only 20% despite intensified multimodal treatment. Therefore, development of novel effective targeted strategies to increase survival and to decrease long-term side effects is urgently needed. Recently, immunotherapies and nanomedicine have been emerging for potent and effective tumor treatments with minimal side effects, raising hopes for effective and safe cures for RMS patients. This review aims to describe the most relevant preclinical and clinical studies in immunotherapy and targeted nanomedicine performed so far in RMS and to provide an insight in future developments.

Peripheral immune profiling of soft tissue sarcoma: perspectives for disease monitoring

Studying the tumor microenvironment and surrounding lymph nodes is the main focus of current immunological research on soft tissue sarcomas (STS). However, due to the restricted opportunity to examine tumor samples, alternative approaches are required to evaluate immune responses in non-surgical patients. Therefore, the purpose of this study was to evaluate the peripheral immune profile of STS patients, characterize patients accordingly and explore the impact of peripheral immunotypes on patient survival. Blood samples were collected from 55 STS patients and age-matched healthy donors (HD) controls. Deep immunophenotyping and gene expression analysis of whole blood was analyzed using multiparametric flow cytometry and real-time RT-qPCR, respectively. Using xMAP technology, proteomic analysis was also carried out on plasma samples. Unsupervised clustering analysis was used to classify patients based on their immune profiles to further analyze the impact of peripheral immunotypes on patient survival. Significant differences were found between STS patients and HD controls. It was found a contraction of B cells and CD4 T cells compartment, along with decreased expression levels of ICOSLG and CD40LG; a major contribution of suppressor factors, as increased frequency of M-MDSC and memory Tregs, increased expression levels of ARG1, and increased plasma levels of IL-10, soluble VISTA and soluble TIMD-4; and a compromised cytotoxic potential associated with NK and CD8 T cells, namely decreased frequency of CD56dim NK cells, and decreased levels of PRF1, GZMB, and KLRK1. In addition, the patients were classified into three peripheral immunotype groups: "immune-high," "immune-intermediate," and "immune-low." Furthermore, it was found a correlation between these immunotypes and patient survival. Patients classified as "immune-high" exhibited higher levels of immune-related factors linked to cytotoxic/effector activity and longer survival times, whereas patients classified as "immune-low" displayed higher levels of immune factors associated with immunosuppression and shorter survival times. In conclusion, it can be suggested that STS patients have a compromised systemic immunity, and the correlation between immunotypes and survival emphasizes the importance of studying peripheral blood samples in STS. Assessing the peripheral immune response holds promise as a useful method for monitoring and forecasting outcomes in STS.

Trends in the use of immunotherapy to treat soft tissue sarcoma

BACKGROUND

The role of immune-oncology (IO) therapy in soft tissue sarcoma (STS) is underexplored. This study characterized IO use in STS.

METHODS

This is a retrospective analysis of patients with a soft tissue mass in the National Cancer Database, 2011-2021. Patients were categorized by IO receipt status. Groupwise testing and proportional trend tests were performed with Chi-squared tests. Multivariate logistic regression was performed to assess factors associated with IO receipt.

RESULTS

Of the 103,092 patients with STS, 1935 (1.9 ​%) received or were recommended IO therapy. IO use increased 10-fold (0.24 ​%-2.5 ​% from 2011 to 2021; p ​< ​0.0001). Patients had higher odds of receiving IO when having higher grade tumors and metastatic disease, and when treated at an academic research center (all p ​< ​0.001).

CONCLUSIONS

IO use in STS is low but increasing and primarily used in the metastatic setting. Future studies should identify biomarkers of IO response and facilitators for treatment receipt.

Comprehensive analysis of prognostic and immunological role of basement membrane-related genes in soft tissue sarcoma

BACKGROUND

Soft tissue sarcoma (STS) represents highly multifarious malignant tumors that often occur in adolescents and have a poor prognosis. The basement membrane, as an ancient cellular matrix, was recently proven to play a vital role in developing abundant tumors. The relationship between basement membrane-related genes and STS remains unknown.

METHODS

Consensus clustering was employed to identify subgroups related to differentially expressed basement membrane-related genes. Cox and least absolute shrinkage and selection operator regression analyses were utilized to construct this novel signature. Then, we established a nomogram and calibration curve, including the risk score and available clinical characteristics. Finally, we carried out functional enrichment analysis and immune microenvironment analysis to investigate enriched pathways and the tumor immune microenvironment related to the novel signature.

RESULTS

A prognostic predictive signature consisting of eight basement membrane-related genes was established. Kaplan-Meier survival curves demonstrated that the patients in the high-risk group had a poor prognosis. Independent analysis illustrated that this risk model could be an independent prognostic predictor. We validated the accuracy of our signature in the validation data set. In addition, gene set enrichment analysis and immune microenvironment analysis showed that patients with low-risk scores were enriched in some pathways associated with immunity. Finally, in vitro experiments showed significantly differential expression levels of these signature genes in STS cells and PSAT1 could promote the malignant behavior of STS.

CONCLUSIONS

The novel signature is a promising prognostic predictor for STS. The present study may improve the prognosis and enhance individualized treatment for STS in the future.

A Potential Role for Nivolumab in the Treatment of Fibrous Dysplasia-Related Pain

Fibrous dysplasia (FD) is a chronic and progressive disorder of bone growth because of decreased osteoblast formation and osteoclast overactivity. Its main symptoms include pain, fracture, and irregular bone growth. Bisphosphonates are the mainstay of therapy for FD with a primary goal of pain relief. A 50-year-old woman presented to ophthalmology in March 2011 with intermittent proptosis, vertical diplopia, and orbital pain. A computed tomography scan of the head revealed a skull base lesion, which was confirmed to be fibrous dysplasia on bone biopsy. Because of significant headache, she was treated with IV pamidronate monthly starting November 2011, which led to pain reduction. Repeated attempts to decrease the frequency of pamidronate were unsuccessful because of breakthrough pain. Oral alendronate and risedronate did not control her symptoms. She remained on risedronate however because of its convenience. In August 2021, she was diagnosed with metastatic melanoma and started nivolumab. Her headache completely resolved for the first time in 10 years. Although nivolumab, a programmed death-1 blocker, has been used in the treatment of bone malignancy, it has not been previously studied in FD. By suppressing RANK ligand-related osteoclastogenesis, nivolumab decreases cancer-associated bone pain. Our case suggests a potential role for nivolumab in treating FD-associated pain.

Development and experimental verification of novel angiogenesis related prognostic model and immune infiltration characterization in osteosarcoma

BACKGROUND

As the most common primary bone cancer, osteosarcoma (OS) still lacks satisfactory therapeutic outcomes. Therefore, it is crucial to further evaluate OS at different risk levels and identify new intervention targets. Many evidences suggest the important role of angiogenesis in OS, but further exploration is needed.

METHODS

We utilized public databases TARGET and GEO and employed bioinformatics algorithms such as LASSO, univariate and multivariate Cox regression analyses, and unsupervised consensus clustering to explore the role of angiogenesis-related genes (AGRGs) in OS. By calculating AGRG scores, we further analyzed OS molecular subtypes based on AGRGs. The correlation between AGRG scores and immune infiltration was subsequently examined. In vitro experiments, including WB, PCR, siRNA, migration, and invasion assays, were used to determine the value of the selected targets for OS.

RESULTS

Ultimately, we established an OS prognosis model based on five AGRGs (COL5A2, CXCL6, FSTL1, NRP1, and TNFRSF21) that can independently validate prognosis levels. In vitro experiments confirmed the aberrant expression of CXCL6 in OS and its potential role in migration and invasion.

CONCLUSION

Our study reveals the impact of angiogenesis on OS from a novel perspective and provides potential intervention targets.

Real-world efficacy, safety data and predictive clinical parameters for treatment outcomes in advanced soft tissue sarcoma treated with combined immunotherapy and antiangiogenic therapy

BACKGROUND

The combination of immunotherapy and antiangiogenic therapy has shown potential in the treatment of numerous malignant tumors, but limited evidence was available for soft tissue sarcomas (STS). Therefore, the aim of the present study is to assess the efficacy and safety of immunotherapy in conjunction with antiangiogenic therapy in patients diagnosed with advanced STS (aSTS).

METHODS

The study enrolled patients with aSTS from January 2014 to October 2022. Eligible participants had previously received anthracycline-based chemotherapy, presented with an anthracycline-resistant sarcoma subtype, or were ineligible for anthracycline treatment due to medical conditions. Following enrollment, these patients received a combination of immunotherapy and antiangiogenic therapy. The primary endpoints were the objective response rate (ORR) and progression-free survival (PFS), while the secondary endpoints included the disease control rate (DCR), overall survival (OS), and the incidence of adverse events.

RESULTS

Fifty-one patients were included in this cohort study. The median duration of follow-up was 15.8 months. The ORR and DCR were 17.6%, and 76.5%, respectively. The median PFS (mPFS) was 5.8 months (95% CI: 4.8-6.8) for all patients, and the median OS had not been reached as of the date cutoff. Multivariate analysis indicated that Eastern Cooperative Oncology Group performance status of 0-1 and ≤ second-line treatment were positive predictors for both PFS and OS. Patients with alveolar soft part sarcoma or clear cell sarcoma had longer mPFS (16.2 months, 95% CI: 7.8-25.6) when compared to those with other subtypes of STS (4.4 months, 95% CI: 1.4-7.5, P < 0.001). Among the observed adverse events, hypertension (23.5%), diarrhea (17.6%), and proteinuria (17.6%) were the most common, with no treatment-related deaths reported.

CONCLUSION

The combination of immunotherapy and antiangiogenic agents showed promising efficacy and acceptable toxicity in patients with aSTS, especially those with alveolar soft part sarcoma or clear cell sarcoma.

Tumour-intrinsic endomembrane trafficking by ARF6 shapes an immunosuppressive microenvironment that drives melanomagenesis and response to checkpoint blockade therapy

Tumour-host immune interactions lead to complex changes in the tumour microenvironment (TME), impacting progression, metastasis and response to therapy. While it is clear that cancer cells can have the capacity to alter immune landscapes, our understanding of this process is incomplete. Herein we show that endocytic trafficking at the plasma membrane, mediated by the small GTPase ARF6, enables melanoma cells to impose an immunosuppressive TME that accelerates tumour development. This ARF6-dependent TME is vulnerable to immune checkpoint blockade therapy (ICB) but in murine melanoma, loss of Arf6 causes resistance to ICB. Likewise, downregulation of ARF6 in patient tumours correlates with inferior overall survival after ICB. Mechanistically, these phenotypes are at least partially explained by ARF6-dependent recycling, which controls plasma membrane density of the interferon-gamma receptor. Collectively, our findings reveal the importance of endomembrane trafficking in outfitting tumour cells with the ability to shape their immune microenvironment and respond to immunotherapy.

Combination treatment with PD1/PDL-1 inhibitors for sarcomas: state of the art, next questions

PURPOSE OF REVIEW

Only a small fraction of sarcomas exhibit recognized parameters of immune sensitivity, such as tumor mutational burden, PDL-1 expression, or microsatellite instability. Combined strategies aimed to modulate tumor microenvironment to increase the efficacy of PD1/PDL-1 inhibitors in sarcoma. Most explored prospective studies were based on combinations of PD1/PDL-1 inhibitors with antiangiogenics, other immune checkpoints, or chemotherapy.

RECENT FINDINGS

Results on 6-month PFS rate, median PFS, and ORR in trials using PD1/PDL-1 inhibitors plus antiangiogenics ranged respectively as 46.9-55%, 4.7-7.8 months and 21-36.7%. In combination with other immune checkpoint inhibitors, the results of median PFS and ORR ranged from 2.8-4.1 months and 10-16%, respectively. In combination with chemotherapy, the best results were obtained with doxorubicin-based regimens compared to other agents. Duplet-based chemotherapy plus anti-PD1/PDL-1 obtained the highest ORR (56.2%) compared with doxorubicin (19-36.7%). Currently, the most robust predictive biomarker for anti-PD1/PDL-1 efficacy is the presence of tertiary lymphoid structures (TLS) with mature dendritic cells.

SUMMARY

Even when direct comparisons between PD1/PDL-1 inhibitor-based combinations and single agents have not been performed yet in sarcoma, some combinations appear promising. Studies controlling heterogeneity by biomarker or histotype selection contribute to an increase in efficacy or knowledge crucial for future comparative trials.

Clinical and translational implications of immunotherapy in sarcomas

Immunotherapy has emerged as promising treatment in sarcomas, but the high variability in terms of histology, clinical behavior and response to treatments determines a particular challenge for its role in these neoplasms. Tumor immune microenvironment (TiME) of sarcomas reflects the heterogeneity of these tumors originating from mesenchymal cells and encompassing more than 100 histologies. Advances in the understanding of the complexity of TiME have led to an improvement of the immunotherapeutic responsiveness in sarcomas, that at first showed disappointing results. The proposed immune-classification of sarcomas based on the interaction between immune cell populations and tumor cells showed to have a prognostic and potential predictive role for immunotherapies. Several studies have explored the clinical impact of immune therapies in the management of these histotypes leading to controversial results. The presence of Tumor Infiltrating Lymphocytes (TIL) seems to correlate with an improvement in the survival of patients and with a higher responsiveness to immunotherapy. In this context, it is important to consider that also immune-related genes (IRGs) have been demonstrated to have a key role in tumorigenesis and in the building of tumor immune microenvironment. The IRGs landscape in soft tissue and bone sarcomas is characterized by the connection between several tumor-related genes that can assume a potential prognostic and predictive therapeutic role. In this paper, we reviewed the state of art of the principal immune strategies in the management of sarcomas including their clinical and translational relevance.

Immunotherapy in Sarcoma: Current Data and Promising Strategies

Traditionally sarcomas have been considered immunologically quiet tumours, with low tumour mutational burden (TMB) and an immunosuppressive tumour microenvironment (TME), consisting of decreased T-cell infiltration and elevated levels of H1F1α, macrophages and neutrophils.1,2 However, research has shown that a subset of sarcomas are immunologically 'hot' with either high TMB, PDL-1 expression, CD8+ T cells or presence of tertiary lymphoid structures (TLS) demonstrating sensitivity to immunotherapy.3,4 Here, we review the current evidence for immunotherapy use in bone sarcomas (BS) and soft tissue sarcomas (STS), with immune checkpoint inhibitors (ICI) and adoptive cellular therapies including engineered T-cell therapies, chimeric antigen receptor (CAR) T-cell therapies, tumour infiltrating lymphocytes (TILs) and cancer vaccines and biomarkers of response.

Correlations between the modification patterns mediated by pyroptosis-related genes, tumor microenvironment, and immunotherapy in soft tissue sarcoma

Soft tissue sarcoma (STS) incidence, progression, and metastasis are tightly linked to the tumor microenvironment (TME). The modification patterns mediated by pyroptosis-related genes (PRGs) in STS are unknown regarding the immune cell infiltration landscape of TME, immunotherapy effect, and prognostic value. First, we downloaded STS samples from the Cancer Genome Atlas (TCGA) and gene-expression omnibus (GEO) databases. Based on 52 PRGs, 2 pyroptosis modification patterns were analyzed, and the associations of pyroptosis modification patterns with immune cell infiltration in the TME were elucidated systematically. To quantify PRG modification patterns in STS patients, we generated a pyroptosis scoring system using principal component analysis (PCA). We identified 2 distinct pyroptosis modification patterns in STS. Compared to PRG cluster A, the prognosis of cluster B was better. These 2 pyroptosis modification patterns corresponded to different characteristics of immune cell infiltration in the TME and biological behaviors. In the pyroptosis scoring system, a high pyroptosis score was connected to higher immune cell infiltration, stronger immune surveillance, immune-killing effects on tumor cells, and better clinical benefits. The results from 3 anti-PD1/PD-L1-treated immune cohorts demonstrated that higher pyroptosis scores are also closely connected to better immunotherapy results. We demonstrated that pyroptosis modification is essential to the STS microenvironment. Moreover, the pyroptosis score is a reliable and independent prognostic factor in STS patients, enabling a richer understanding of the STS microenvironment and the screening of immunotherapy candidates, predicting the immunotherapeutic effects for individual STS patients, and guiding the use of chemotherapy drugs.

Immune evasion in lung metastasis of leiomyosarcoma: upregulation of EPCAM inhibits CD8+ T cell infiltration

BACKGROUND

Leiomyosarcomas are among the most common histological types of soft tissue sarcoma (STS), with no effective treatment available for advanced patients. Lung metastasis, the most common site of distant metastasis, is the primary prognostic factor. We analysed the immune environment targeting lung metastasis of STS to explore new targets for immunotherapy.

METHODS

We analysed the immune environment of primary and lung metastases in 38 patients with STS using immunohistochemistry. Next, we performed gene expression analyses on primary and lung metastatic tissues from six patients with leiomyosarcoma. Using human leiomyosarcoma cell lines, the effects of the identified genes on immune cells were assessed in vitro.

RESULTS

Immunohistochemistry showed a significant decrease in CD8+ cells in the lung metastases of leiomyosarcoma. Among the genes upregulated in lung metastases, epithelial cellular adhesion molecule (EPCAM) showed the strongest negative correlation with the number of CD8+ cells. Transwell assay results showed that the migration of CD8+ T cells was significantly increased in the conditioned media obtained after inhibition or knock down of EPCAM.

CONCLUSIONS

EPCAM was upregulated in lung metastases of leiomyosarcoma, suggesting inhibition of CD8+ T cell migration. Our findings suggest that EPCAM could serve as a potential novel therapeutic target for leiomyosarcoma.

Efficacy of tyrosine kinase inhibitors in patients with advanced or metastatic sarcomas after prior chemotherapy: A meta-analysis

BACKGROUND

Sarcoma is a heterogeneous malignancy arising from interstitial tissue. Anthracycline-based therapy is the first-line treatment recommended by guidelines for patients with locally advanced or metastatic unresectable sarcoma. Recently, targeted therapies, in particular tyrosine kinase inhibitors (TKIs), have made significant progress in the treatment of sarcoma, and their efficacy has been investigated in randomized controlled trials. The aim of this meta-analysis is to evaluate the efficacy of TKIs in patients with advanced or metastatic sarcoma who have previously received chemotherapy.

METHODS

We completed a meta-analysis after conducting literature searches in PubMed, Embase, and Cochrane. The single-drug, placebo-controlled, randomized controlled clinical trials of TKIs in patients with advanced or progressive sarcoma who have previously received chemotherapy are available for inclusion in the study. The observation results were objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). The subgroup analysis was performed according to histological subtypes of sarcoma.

RESULTS

This study included 6 studies, including 1033 patients. The ORR (OR: 7.99, 95% CI: 3.62-19.61, P < .00001), DCR (OR: 2.54, 95% CI: 1.27-5.08, P = .009), PFS (HR: 0.46, 95% CI: 0.34-0.62, P < .00001), and OS (HR: 0.80, 95% CI: 0.67-0.96, P = .02) of patients treated with TKIs were better than those in the placebo group.

CONCLUSIONS

In patients with advanced sarcoma, TKIs have been shown to have advantages in terms of ORR, DCR and PFS and OS. Multi-targeted TKIs may be considered as one of the second-line treatment options for sarcoma patients who have received prior chemotherapy.

Treatments and prognostic factors for bone and soft tissue sarcoma in non-urban areas in Japan

BACKGROUND

Although bone and soft tissue sarcoma is recognized as a rare cancer that originates throughout the body, few comprehensive reports regarding it have been published in Japan.

PATIENTS AND METHODS

Bone and soft tissue sarcomas were tabulated from the Cancer Registries at eight university hospitals in the Chugoku-Shikoku region. Prognostic factors in cases were extracted in a single facility and have been analyzed.

RESULTS

From 2016 to 2019, 3.4 patients with bone and soft tissue sarcomas per a general population of 100,000 were treated at eight university hospitals. The number of patients who underwent multidisciplinary treatment involving collaboration among multiple clinical departments has been increasing recently. In the analysis carried out at a single institute (Ehime University Hospital), a total of 127 patients (male/female: 54/73) with an average age of 67.0 y (median 69.5) were treated for four years, with a 5-year survival rate of 55.0%. In the analysis of prognostic factors by multivariate, disease stage and its relative treatment, renal function (creatinine), and a patient's ability of self-judgment, and a patient's mobility and physical capability were associated with patient prognosis regarding bone and soft tissue sarcomas. Interestingly, age did not affect the patient's prognosis (> 70 vs ≦ 70).

CONCLUSIONS

Physical and social factors may affect the prognosis of patients with bone and soft tissue sarcomas, especially those living in non-urban areas.

Sarcoma in patients with Lynch syndrome and response to immunotherapy

BACKGROUND

Lynch syndrome (LS) is an autosomal dominant genetic predisposition to multiple malignancies and is characterized by deficient DNA mismatch repair. Increased incidence of sarcomas is not formally ascribed to LS; however, increasing evidence suggests a preponderance of these malignancies in affected families. Sarcomas typically possess a low tumor mutational burden and incite a poor immune infiltrate, thereby rendering them poorly responsive to immunotherapy.

METHODS

We searched the University of California, Los Angeles (UCLA) sarcoma program database for patients with a diagnosis of sarcoma and LS from 2016 to 2023. Three such patients were identified and all three were treated with PD1 blockade.

RESULTS

We present three cases of LS-associated sarcomas (two soft tissue sarcoma and one osteosarcoma) with increased tumor mutational burdens. These patients were each treated with an anti-PD1 antibody and experienced a response far superior to that reported for non-LS-associated sarcomas.

CONCLUSIONS

Increased mutational burden and immune infiltrate are observed for sarcomas associated with LS. Although unselected patients with sarcoma have demonstrated poor response rates to immunotherapy, our findings suggest that patients with Lynch-associated sarcomas are more likely to respond to treatment with anti-PD1. These patients should be given consideration for immunotherapy.

Combining nanoparticle albumin-bound paclitaxel with camrelizumab in advanced soft tissue sarcoma: activity, safety, and future perspectives

Background: It is still uncertain whether Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) and programmed cell death protein 1 (PD-1) inhibitor have synergistic effects on metastatic soft tissue sarcomas (STSs). The purpose of this study was to evaluate the safety and activity of nab-paclitaxel plus camrelizumab (a PD-1 inhibitor) in patients with advanced STS who had previously failed chemotherapy. Methods: In this single-center, open-label, single-arm phase II clinical trial, patients with advanced (unresectable or metastatic) STS who had previously failed chemotherapy received up to six cycles of nab-paclitaxel plus camrelizumab, whereas camrelizumab treatment was continued for up to 1 year. The median progression-free survival (PFS), objective response rate (ORR) and safety were collected and evaluated. Results: This trial included 40 patients (28 men and 12 women). The overall ORR was 22.5%, and the median PFS was 1.65 months (95% confidence interval [CI], 1.3-2.0 months). Patients with epithelioid sarcoma demonstrated a longer PFS compared with those with other histological subtypes (2.3 months vs. 1.5 months, respectively); however, this difference was not significant. Patients who had received only one line of previous chemotherapy had a significantly longer PFS compared with those who had undergone two or more lines of previous chemotherapy (2.8 months vs. 1.3 months, respectively, p = 0.046). In terms of safety, the toxicity of this combination therapy is mild and no serious adverse events have occurred. Conclusion: Nab-paclitaxel plus camrelizumab exhibited modest activity and mild toxicity in treating epithelioid sarcoma, angiosarcoma, and fibrosarcoma. The overall effectiveness of this treatment regimen for advanced STS is relatively low. Further research on combining nab-paclitaxel with effective drugs, including chemotherapy and targeted agents, for these specific STS subtypes is needed.

PTEN pathogenic variants are associated with poor prognosis in patients with advanced soft tissue sarcoma

BACKGROUND

We aimed to examine whether PTEN pathogenic variants (mutPTEN) were associated with overall survival (OS) in patients with advanced soft tissue sarcoma (STS) with the presence of one or more of the most common genomic alterations including p53, CDKN2A, RB1, and ATRX pathogenic variants.

METHODS

This study included patients from Kaiser Permanente Northern California and Stanford Cancer Center with grade 2 or higher locally advanced and metastatic STS.

RESULTS

A total of 174 patients had leiomyosarcoma (LMS), 136 had undifferentiated pleomorphic sarcoma (UPS), 78 had Liposarcoma (LPS), and 214 had other histology subtypes (Others). Among all patients with STS, OS was worse for those with mutPTEN versus wild-type PTEN (wtPTEN, adjusted HR [aHR] = 1.58 [95% CI, 1.11-2.23]), mutCDKN2A vs wtCDKN2A (aHR = 1.33 [95% CI .99-1.80]), and mutRB1 vs wtRB1 (aHR = 1.26 [95% CI 0.93-1.70[), while OS was similar for mutp53 vs wtp53 and mutATRX vs wtATRX. MutPTEN versus wtPTEN was consistently associated with worse OS in histologic subtypes including LMS and UPS and molecular subgroups.

CONCLUSION

MutPTEN vs wtPTEN was associated with worse OS in advanced STS. If confirmed, our findings could be helpful for prognostic stratification in clinical practice and for further understanding the molecular mechanisms of STS.

Sex-dependent Prognosis of Patients with Advanced Soft Tissue Sarcoma

PURPOSE

To examine whether overall survival (OS) differs for male and female patients with advanced soft-tissue sarcoma (STS).

EXPERIMENTAL DESIGN

The study included patients from Kaiser Permanente Northern California and Stanford Cancer Center with grade 2 and 3 locally advanced or metastatic STS whose tumor underwent next-generation sequencing. We used Cox regression modeling to examine association of sex and OS adjusting for other important factors.

RESULTS

Among 388 eligible patients, 174 had leiomyosarcoma (LMS), 136 had undifferentiated pleomorphic sarcoma (UPS), and 78 had liposarcoma. OS for male versus female patients appeared to be slightly better among the full cohort [HR = 0.89; 95% confidence interval (CI), 0.66-1.20]; this association appeared to be stronger among the subsets of patients with LMS (HR = 0.76; 95% CI, 0.39-1.49) or liposarcoma (HR = 0.74; 95% CI, 0.32-1.70). Better OS for male versus female patients was also observed among all molecular subgroups except mutRB1 and mutATRX, especially among patients whose tumor retained wtTP53 (HR = 0.73; 95% CI, 0.44-1.18), wtCDKN2A (HR = 0.85; 95% CI, 0.59-1.23), wtRB1 (HR = 0.73; 95% CI, 0.51-1.04), and among patients whose tumor had mutPTEN (HR = 0.37; 95% CI, 0.09-1.62). OS also appeared to be better for males in the MSK-IMPACT and TCGA datasets.

CONCLUSIONS

A fairly consistent pattern of apparent better OS for males across histologic and molecular subgroups of STS was observed. If confirmed, our results could have implications for clinical practice for prognostic stratification and possibly treatment tailoring as well as for future clinical trials design.

Predicting prognosis and immune status in sarcomas by identifying necroptosis-related lncRNAs

BACKGROUND

Sarcomas are a type of highly heterogeneous malignant tumors originating from mesenchymal tissues. Necroptosis is intricately connected to the oncogenesis and progression of tumors. The main goal of this research is to assess the prognostic value of necroptosis-related lncRNAs (NRlncRNAs) in sarcomas and to develop a risk model based on NRlncRNAs to evaluate prognostic and immune status of the sarcomas.

METHODS

We screened NRlncRNAs using the gene co-expression network, developed a prognostic risk model of sarcomas, and then verified the model. Following that, various bioinformatics analysis algorithms were employed to analyze the distinct characteristics of patients of the risk model. Furthermore, the function and regulatory mechanism of NRlncRNA SNHG6 in sarcomas were investigated through osteosarcoma cell experiments, such as qRT-PCR, Western blot, CCK-8, clone formation, and transwell assay.

RESULTS

We successfully developed a NRlncRNAs-related prognostic risk model and screened 5 prognosis-related NRlncRNAs, with SNGH6 being the most significant for prognosis of patients. According to results, the significant differences exist in prognosis, clinical characteristics, and tumor immune status among patients of the risk model. The experiments of osteosarcoma cells demonstrated that NRlncRNA SNHG6 knockdown significantly attenuated the cells' proliferation, migration, and invasion. qRT-PCR and WB results showed that SNHG6 regulated AXL and AKT signaling.

CONCLUSIONS

We have developed an innovative investigation on NRlncRNAs, which can serve as a reference for diagnosis, therapy, and prognosis of sarcomas. Additionally, we demonstrated that NRlncRNA SNHG6 regulated AXL and AKT signaling in osteosarcoma cells and the proliferation, migration, and invasion of tumor cells.

Role of high‑sensitivity C‑reactive protein in patients with sarcoma

Immunotherapy has shown promising results in lung cancer and melanomas; however, the responses have been poor in patients with sarcoma. Understanding the relationship between the immune system and sarcoma is essential to develop improved immunotherapy approaches. High-sensitivity C-reactive protein (hs-CRP) has been proposed as a prognostic marker in other cancer types; however, to the best of our knowledge, the association between hs-CRP levels and mortality in patients with sarcoma has not been investigated. The present prospective, non-randomised, non-interventional explorative study investigated the prognostic value of hs-CRP in patients with sarcoma. Patients referred to the sarcoma centre of Aarhus University Hospital (Aarhus, Denmark) were included between April 2014 and December 2020. Clinical data were obtained from the national quality sarcoma database and biomarkers other than hs-CRP were obtained from the clinical laboratory information system. The study cohort consisted primarily of patients with localised sarcoma. hs-CRP was significantly higher in patients with bone sarcoma (P=0.022) and soft tissue sarcoma (STS; P<0.001) compared with control patients. For STS, grade III tumours but not metastatic disease were associated with a higher hs-CRP level (P=0.0001). Elevated hs-CRP levels were associated with increased overall mortality [hazard ratio (HR), 1.91; 95% CI, 1.33-2.75; P=0.001]. Furthermore, elevated hs-CRP levels were also associated with decreased progression-free survival (HR, 1.64; 95% CI, 1.17-2.29; P=0.004). Furthermore, for patients with hs-CRP <8 mg/l, higher hs-CRP was associated with an increased risk of recurrent disease and reduced overall survival compared with those of patients with low hs-CRP. In conclusion, the present study demonstrated that hs-CRP was a prognostic factor for overall mortality and progression-free survival in patients with localised sarcoma at the time of diagnosis. Further studies are required to investigate the mechanism behind the association between hs-CRP and sarcoma prognosis and its potential use in clinical practice.

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.

Brain metastases of sarcoma: a rare phenomenon in rare tumours

The usual site for distant metastases of sarcoma is lungs, while brain metastasis (BM) occurs much less frequently and usually late in the disease progression. Despite the advancement in cancer treatment, the outcome for patients with brain metastasis is poor, and their lifespan is short. The frequency of BM in sarcoma seems to be affected by the location and histology of the primary tumour. Sarcoma subtypes with a high propensity for brain metastasis are ASPS, leiomyosarcoma and osteosarcoma. There are no clear guidelines for the treatment of sarcoma brain metastasis. However, therapeutic options include surgery, radiotherapy and chemotherapy, and are often combined. Targeted therapies are a promising treatment option for sarcoma but require investigation in patients with BM. The following review presents the data on sarcoma brain metastasis incidence, treatment and prognosis.

ARF6-dependent endocytic trafficking of the Interferon-γ receptor drives adaptive immune resistance in cancer

Adaptive immune resistance (AIR) is a protective process used by cancer to escape elimination by CD8+ T cells. Inhibition of immune checkpoints PD-1 and CTLA-4 specifically target Interferon-gamma (IFNγ)-driven AIR. AIR begins at the plasma membrane where tumor cell-intrinsic cytokine signaling is initiated. Thus, plasma membrane remodeling by endomembrane trafficking could regulate AIR. Herein we report that the trafficking protein ADP-Ribosylation Factor 6 (ARF6) is critical for IFNγ-driven AIR. ARF6 prevents transport of the receptor to the lysosome, augmenting IFNγR expression, tumor intrinsic IFNγ signaling and downstream expression of immunosuppressive genes. In murine melanoma, loss of ARF6 causes resistance to immune checkpoint blockade (ICB). Likewise, low expression of ARF6 in patient tumors correlates with inferior outcomes with ICB. Our data provide new mechanistic insights into tumor immune escape, defined by ARF6-dependent AIR, and support that ARF6-dependent endomembrane trafficking of the IFNγ receptor influences outcomes of ICB.

The quest for effective immunotherapies against malignant peripheral nerve sheath tumors: Is there hope?

Immune-based therapies represent a new paradigm in the treatment of multiple cancers, where they have helped achieve durable and safe clinical responses in a growing subset of patients. While a wealth of information is available concerning the use of these agents in treating the more common malignancies, little has been reported about the use of immunotherapies against malignant peripheral nerve sheath tumors (MPNSTs), a rare form of soft tissue sarcoma that arises from the myelin sheaths that protect peripheral nerves. Surgical resection has been the mainstay of therapy in MPNSTs, but the recurrence rate is as high as 65%, and chemotherapy is generally ineffective. The immune contexture of MPNSTs, replete with macrophages and a varying degree of T cell infiltration, presents multiple opportunities to design meaningful therapeutic interventions. While preliminary results with macrophage-targeting strategies and oncolytic viruses are promising, identifying the subset of patients that respond to immune-based strategies will be a milestone. As part of our effort to help advance the use of immunotherapy for MPNSTs, here we describe recent insights regarding the immune contexture of MPNSTs, discuss emerging immune-based strategies, and provide a brief overview of potential biomarkers of response.

Exploratory study of an anti-PD-L1/TGF-β antibody, TQB2858, in patients with refractory or recurrent osteosarcoma and alveolar soft part sarcoma: a report from Chinese sarcoma study group (TQB2858-Ib-02)

BACKGROUND

Novel and effective immunotherapies are required for refractory or recurrent sarcomas. Transforming growth factor-beta (TGF-β) is a diverse regulatory and fibrogenic protein expressed in multiple sarcoma tumors that promotes epithelial-mesenchymal transition and excessive deposition of extracellular matrix. This study evaluated the efficacy and safety of the anti-PD-L1/TGF-β antibody TQB2858 in patients with refractory osteosarcoma and alveolar soft part sarcoma (ASPS).

METHODS

This single-arm phase 1b exploratory study included patients with refractory osteosarcoma or ASPS who had previously undergone at least two lines of systemic therapy. Patients were administered 1200 mg of TQB2858 once every 3 weeks. The primary endpoint was objective response rate (ORR), with null and alternative hypotheses of ORR ≤5% and ≥20%, respectively. Exploratory biomarker analyses using immunohistochemistry (IHC) staining (for PD-L1 and TGF-β) were performed on pre-treatment tumor samples.

RESULTS

Eleven eligible patients were included in this study. TQB2858 did not demonstrate evidence of efficacy as 0/5 osteosarcomas had any objective response, while 2/6 ASPS showed a partial response. The median progression-free survivals were 1.51 (1.38, Not Evaluable) and 2.86 (1.38, Not Evaluable) months for the osteosarcoma and ASPS groups, respectively. None of the administered cycles met the criteria for unacceptable toxicity. Other Grade 3 toxicities included abnormal liver function and elevation of γ-glutamyl transferase. IHC analysis revealed that functional enrichment in the TGF-β pathway or PD-L1 was not associated with treatment outcomes.

CONCLUSIONS

The combination of PD-L1 and TQB2858 did not significantly improve the ORR in patients with recurrent osteosarcoma. However, it improved immunogenic responses in ASPS, even after progression upon anti-PD-1/PD-L1 therapy, with an acceptable safety profile. IHC profiling with pathway enrichment analysis may not have any predictive value for survival outcomes.

TRIAL REGISTRATION

Prospectively registered in the Ethical Review Committee of Peking University People's Hospital. The trial registration number is 2021PHA105-001 and 2021PHA140-001 and the registration date was March 2, 2022.

CLINICALTRIALS

gov Identifier CTR20213001 and CTR20220390.

Characterizing T-cell dysfunction and exclusion signatures in malignant peripheral nerve sheath tumors reveals susceptibilities to immunotherapy

PURPOSE

Malignant peripheral nerve sheath tumors (MPNSTs) are malignant tumors that arise from peripheral nerves and are the leading cause of mortality in Neurofibromatosis Type 1 (NF1). In this study, we characterized whether transcriptomic signatures of T-cell dysfunction (TCD) and exclusion (TCE) that inversely correlate with response to immune checkpoint blockade (ICB) immunotherapy exist in MPNSTs.

METHODS

MPNST transcriptomes were pooled from Gene Expression Omnibus (GEO). For each sample, a tumor immune dysfunction and exclusion (TIDE) score, TCD and TCE subscores, and cytotoxic T-cell(CTL) level were calculated. In the TIDE predictive algorithm, tumors are predicted to have an ICB response if they are either immunologically hot (CTL-high) without TCD or immunologically cold (CTL-low) without TCE. TIDE scores greater than zero correspond with ICB nonresponse.

RESULTS

73 MPNST samples met inclusion criteria, including 50 NF1-associated MPNSTs (68.5%). The average TIDE score was + 0.41 (SD = 1.16) with 22 (30.1%) predicted ICB responders. 11 samples were CTL-high (15.1%) with an average TCD score of + 0.99 (SD = 0.63). Among 62 CTL-low tumors, 21 were predicted to have ICB response with an average TCE score of + 0.31(SD = 1.20). Age(p = 0.18), sex(p = 0.41), NF1 diagnosis (p = 0.17), and PRC2 loss(p = 0.29) were not associated with ICB responder status.

CONCLUSIONS

Transcriptomic analysis of TCD and TCE signatures in MPNST samples reveals that a select subset of patients with MPNSTs may benefit from ICB immunotherapy.

Pembrolizumab in patients with rare and ultra-rare sarcomas (AcSé Pembrolizumab): analysis of a subgroup from a non-randomised, open-label, phase 2, basket trial

BACKGROUND

Sarcoma is a heterogeneous group of diseases with few treatment options. Immunotherapy has shown little activity in studies including unselected sarcomas, but immune checkpoint blockers have shown activity in specific histotypes. We evaluated the activity of pembrolizumab in rare and ultra-rare sarcomas.

METHODS

AcSé Pembrolizumab is an ongoing phase 2, basket, multitumour study investigating the activity of pembrolizumab monotherapy in rare cancers. Here, we report the results obtained in patients with selected histotypes of rare sarcomas (incidence of less than one case per 1 000 000 people per year) recruited at 24 French hospitals. Key inclusion criteria were age 15 years or older, Eastern Cooperative Oncology Group performance status of 0-1, and advanced disease that was untreated and resistant to treatment. Patients were given pembrolizumab 200 mg intravenously on day 1 of every 21-day cycle for a maximum of 24 months. The primary endpoint was objective response rate at week 12 using Response Evaluation Criteria in Solid Tumours version 1.1, assessed by local investigators. The primary endpoint and safety were analysed in the intention-to-treat population. The AcSé Pembrolizumab study is registered with ClinicalTrials.gov, NCT03012620.

FINDINGS

Between Sept 4, 2017, and Dec 29, 2020, 98 patients were enrolled, of whom 97 received treatment and were included in analyses (median age 51 years [IQR 35-65]; 53 [55%] were male; 44 [45%] were female; no data were collected on race or ethnicity). 34 (35%) patients had chordomas, 14 (14%) had alveolar soft part sarcomas, 12 (12%) had SMARCA4-deficient sarcomas or malignant rhabdoid tumours, eight (8%) had desmoplastic small round cell tumours, six (6%) had epithelioid sarcomas, four (4%) had dendritic cell sarcomas, three (3%) each had clear cell sarcomas, solitary fibrous tumours, and myxoid liposarcomas, and ten (10%) had other ultra-rare histotypes. As of data cutoff (April 11, 2022), median follow-up was 13·1 months (range 0·1-52·8; IQR 4·3-19·7). At week 12, objective response rate was 6·2% (95% CI 2·3-13·0), with no complete responses and six partial responses in the 97 patients. The most common grade 3-4 adverse events were anaemia (eight [8%] of 97), alanine aminotransferase and aspartate aminotransferase increase (six [6%]), and dyspnoea (five [5%]). 86 serious adverse events were reported in 37 patients. Five deaths due to adverse events were reported, none of which were determined to be related to treatment (two due to disease progression, two due to cancer, and one due to unknown cause).

INTERPRETATION

Our data show the activity and manageable toxicity of pembrolizumab in some rare and ultra-rare sarcoma histotypes, and support the PD-1/PD-L1 pathway as a potential therapeutic target in selected histotypes. The completion of the basket study will provide further evidence regarding the activity and toxicity of pembrolizumab in identified rare types of cancer.

FUNDING

The Ligue contre le cancer, INCa, MSD.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Comprehensive Immune Profiling Unveils a Subset of Leiomyosarcoma with "Hot" Tumor Immune Microenvironment

Purpose: To investigate the immune biomarker in Leiomyosarcoma (LMS), which is rare and recognized as an immune cold cancer showing a poor response rate (<10%) to immune checkpoint inhibitors (ICIs). However, durable response and clinical benefit to ICIs has been observed in a few cases of LMS, including, but not only, LMS with tertiary lymphoid structure (TLS) structures. Patients and methods: We used comprehensive transcriptomic profiling and a deconvolution method extracted from RNA-sequencing gene expression data in two independent LMS cohorts, the International Cancer Genome Consortium (ICGC, N = 146) and The Cancer Genome Atlas (TCGA, N = 75), to explore tumor immune microenvironment (TIME) in LMS. Results: Unsupervised clustering analysis using the previously validated two methods, 90-gene signature and Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT), identified immune hot (I-H) and immune high (I-Hi) LMS, respectively, in the ICGC cohort. Similarly, immune active groups (T-H, T-Hi) were identified in the TCGA cohort using these two methods. These immune active ("hot") clusters were significantly associated, but not completely overlapping, with several validated immune signatures such as sarcoma immune class (SIC) classification and TLS score, T cell inflamed signature (TIS) score, immune infiltration score (IIS), and macrophage score (M1/M2), with more patients identified by our clustering as potentially immune hot. Conclusions: Comprehensive immune profiling revealed a subset of LMS with a distinct active ("hot") TIME, consistently associated with several validated immune signatures in other cancers. This suggests that the methodologies that we used in this study warrant further validation and development, which can potentially help refine our current immune biomarkers to select the right LMS patients for ICIs in clinical trials.

Anti-PD-1 therapy in advanced sarcomas: is cutaneous primary site a stronger predictor of response than histologic subtype?

BACKGROUND

Immune checkpoint inhibitors (ICIs) have shown modest antitumor activity in unselected advanced sarcomas. Histology driven approach to patient selection is the current standard for off-label anti-programmed cell death 1 (PD1) immunotherapy use.

METHODS

We retrospectively reviewed the clinical characteristics and outcomes of patients with advanced sarcoma who were treated with off label anti-PD1 immunotherapy at our center.

RESULTS

A total of 84 patients with 25 histological subtypes were included. Nineteen patients (23%) had a cutaneous primary tumor site. Eighteen patients (21%) were classified as having clinical benefit, including 1 patient with complete response, 14 with partial response, and 3 with stable disease lasting over 6 months with previously progressive disease. Cutaneous primary site location was associated with higher clinical benefit rate (58% vs. 11%, p < 0.001), longer median PFS (8.6 vs. 2.5 months, p = 0.003) and OS (19.0 vs. 9.2 months, p = 0.011), compared to non-cutaneous primary. Patients with histological subtypes that pembrolizumab is indicated per current National Comprehensive Cancer Network guidelines had modestly higher rate of clinical benefit versus other histologies, however, the difference was statistically insignificant (29% vs. 15%, p = 0.182) and no statistically significant difference in PFS or OS was observed between these groups. Immune-related adverse events were more frequently seen among patients with clinical benefit (72% vs. 35%, p = 0.007).

CONCLUSIONS

Anti-PD1-based immunotherapy is highly efficacious in advanced sarcomas of cutaneous primary site. Cutaneous primary site location is a stronger predictor of ICI response than histologic subtype and should be accounted for in treatment guidelines and clinical trial design.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.