ReviewMechanismMixed resultsLimited evidenceTier 4 · clinical
International journal of gynecological cancer : official journal of the International Gynecological Cancer Society · Jan 2026
uterine leiomyosarcoma
This is a narrative review of the immune environment of uterine leiomyosarcoma and the potential role of immune checkpoint inhibitors. The authors report variable PD-L1 expression, heterogeneous lymphocytic infiltration, and interactions with tumor-associated macrophages, note modest response rates to checkpoint inhibitors in clinical trials, and discuss that dual PD-1/CTLA-4 blockade and chemotherapy-induced immunogenic cell death may enhance immune activation in select patients. They conclude that combinatorial and personalized strategies, improved immune profiling, and macrophage-targeted approaches merit further study.
Studied with: anti-CTLA-4 + anti-PD-1 dual checkpoint blockade, chemotherapy (to induce immunogenic cell death), targeted immunomodulation, macrophage-targeted therapies.
Key findings
- Uterine leiomyosarcoma has a variable tumor immune microenvironment including variable PD-L1 expression and differential lymphocytic infiltration.
- Interactions with tumor-associated macrophages shape immune responses in leiomyosarcoma.
- Clinical trials of immune checkpoint inhibitors in leiomyosarcoma have produced modest response rates.
- Molecular analyses suggest that specific sub-groups of leiomyosarcoma patients may derive greater benefit from checkpoint inhibition.
- Dual-checkpoint blockade combining anti-PD-1 and anti-CTLA-4 has demonstrated enhanced immune activation in select patients.
- Chemotherapy-induced immunogenic cell death has been explored as a complementary approach to immunotherapy.
- Authors recommend innovative combinatorial strategies, improved patient selection, enhanced macrophage-targeted therapies, and optimized immune profiling for future research.
Limitations: Narrative review only—no new primary experimental or patient-level data are presented.; Conclusions are based on heterogeneous published studies and molecular analyses rather than definitive randomized trial evidence.; Abstract reports only 'modest response rates' in trials without quantitative pooled estimates or meta-analysis.; Leiomyosarcoma heterogeneity and rarity limit generalizability of existing trial results (as noted by authors)..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed
Human · observationalMechanismReported positiveLimited evidenceTier 3 · early humann = 71
Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc · Nov 2025 · Array-based global methylation profiling analysis of tumor samples (71 uterine leiomyosarcoma) compared with several other uterine mesenchymal tumors and soft tissue leiomyosarcoma
uterine leiomyosarcomauterine mesenchymal tumorssoft tissue leiomyosarcoma
Researchers performed array-based global methylation profiling on 71 uterine leiomyosarcoma samples and compared them to other uterine mesenchymal tumors and soft tissue leiomyosarcoma. They found that uLMS have distinct methylation patterns versus other tumor types and that methylation profiling identifies two distinct uLMS subgroups with differing copy number alterations and distinct histologic and clinical behaviors. The authors report this is the first study to describe methylation profiling as a diagnostic tool to differentiate uLMS from its mimics.
Key findings
- uLMS demonstrated distinct methylation patterns differing from all other tumor types.
- Methylation profiling defines 2 distinct subgroups of uLMS with differing copy number alterations.
- The two methylation-defined subgroups exhibit unique histologic and clinical behaviors, supported by differences in methylation pathway analysis.
- This study is the first to report methylation profiling as a useful diagnostic tool in differentiating uLMS from mimics.
Limitations: Observational molecular profiling study without interventional or longitudinal clinical trial data; Sample size limited to 71 uLMS; sizes of comparator tumor groups not reported in abstract; No external validation cohort reported in the abstract; No functional validation experiments described to confirm biological significance of methylation differences; Details on clinical outcome measures, follow-up duration, and statistical metrics are not provided in the abstract.
AI summary of the abstract, human-reviewed · Sep 2026. Describes what this study reported, not medical advice. View on PubMed
Human · observationalMechanismReported positiveLimited evidenceTier 3 · early humann = 6
Frontiers in immunology · Aug 2025 · Single-cell RNA sequencing (scRNA-seq) of metastatic lesions from a treatment-naïve uterine leiomyosarcoma patient compared to normal uterine myometrium samples (MMM, n=5); integrated analyses including CNV, pseudotime, cell-cell communication, functional enrichment, and mpIF validation; survival correlations with TCGA-SARC cohort.
uterine leiomyosarcoma
The authors performed single-cell RNA sequencing on metastatic lesions from one treatment-naïve uterine leiomyosarcoma patient and compared the data to five normal myometrium samples. They found an immunosuppressed tumor microenvironment characterized by exhausted CD8+ T cells, M2-like tumor-associated macrophages, and immature N2 neutrophils enriched in metastatic foci; these features correlated with poorer prognosis in TCGA-SARC analyses. The study also identified cell-cell communication axes (MIF-(CD74+CD44), CXCL8) and candidate biomarkers (EDARADD, CLDN10, TMIGD2) and dysregulated pathways (TGF-beta, angiogenesis, MIF signaling).
Key findings
- The tumor microenvironment showed prominent immunosuppression with exhausted CD8+ T cells, with initial markers (CCR7, MAL) diminishing over time and exhaustion markers (LAG3, HAVCR2, TIGIT) enriched.
- M2-polarized macrophages were mainly composed of M2-like TAMs with tumor-promoting characteristics (CD163, FTH1, FTL, TIMP1) and there was a polarization trajectory from M1 to M2.
- Immature, tumor-promoting N2 neutrophils (CD15+EDARADD+) were enriched in metastatic foci and associated with poor prognosis.
- Cell-cell communication analyses highlighted MIF-(CD74+CD44) interactions between T/B cells and a role for the CXCL8 signaling axis in promoting angiogenesis, TAM polarization, and immunosuppression.
- Constructed a comprehensive single-cell map of ULSA, defined a metastasis-susceptible cell subset (U11-EDARADD), and nominated biomarkers (EDARADD, CLDN10, TMIGD2) and dysregulated pathways (TGF-β, angiogenesis, MIF signaling) as possible targets for future combined-immunotherapy development.
Limitations: Tumor single-cell data derive from a single ULSA patient (metastatic lesions from one individual), limiting generalizability.; Normal comparator samples are limited (MMM, n=5) and cohort sizes are small.; Observational single-cell profiling cannot establish causal relationships between identified cell states/pathways and clinical outcomes or therapy resistance.; Survival associations were assessed using TCGA-SARC correlations (indirect validation) rather than validation in an independent ULSA cohort.; No interventional or functional experiments reported to validate that identified biomarkers/pathways drive immunosuppression or therapy resistance..
AI summary of the abstract, human-reviewed · Sep 2026. Describes what this study reported, not medical advice. View on PubMed · Full text