High-Grade Endometrial Stromal Sarcoma: Molecular Alterations and Potential Immunotherapeutic Strategies

Molecular Insights in Endometrial Stromal Sarcomas: Exploring New Targets for Novel Therapeutic Approaches

Uterine mesenchymal tumors (UMTs) are the second most common type of tumors within the uterus corpus after endometrial carcinomas. Among the UMTs, smooth muscle neoplasms are the most common subtype, followed by endometrial stromal sarcoma (ESS). ESSs are uncommon malignancies characterized by molecular heterogeneity and an aggressive behavior. Their management poses significant challenges, particularly for high-grade subtypes. Surgery is the primary intervention for localized disease, while the role of adjuvant therapies, including radiation and chemotherapy, must be better investigated. Hormonal therapy has shown efficacy in low-grade cases but limited success in high-grade tumors. Recent advancements in molecular profiling have revealed potential targets, offering promise for personalized treatments. However, novel therapeutic strategies are urgently needed to improve patient outcomes, particularly for advanced and recurrent disease. This review offers a perspective on the possible novel therapeutic approaches based on the most recent molecular analyses performed on endometrial stromal sarcomas.

Integrated Transcriptomic Landscape and Deep Learning Based Survival Prediction in Uterine Sarcomas

PURPOSE

The genomic characteristics of uterine sarcomas have not been fully elucidated. This study aimed to explore the genomic landscape of the uterine sarcomas (USs).

MATERIALS AND METHODS

Comprehensive genomic analysis through RNA-sequencing was conducted. Gene fusion, differentially expressed genes (DEGs), signaling pathway enrichment, immune cell infiltration, and prognosis were analyzed. A deep learning model was constructed to predict the survival of US patients.

RESULTS

A total of 71 US samples were examined, including 47 endometrial stromal sarcomas (ESS), 18 uterine leiomyosarcomas (uLMS), three adenosarcomas, two carcinosarcomas, and one uterine tumor resembling an ovarian sex-cord tumor. ESS (including high-grade ESS [HGESS] and low-grade ESS [LGESS]) and uLMS showed distinct gene fusion signatures; a novel gene fusion site, MRPS18A-PDC-AS1 could be a potential diagnostic marker for the pathology differential diagnosis of uLMS and ESS; 797 and 477 uterine sarcoma DEGs (uDEGs) were identified in the ESS vs. uLMS and HGESS vs. LGESS groups, respectively. The uDEGs were enriched in multiple pathways. Fifteen genes including LAMB4 were confirmed with prognostic value in USs; immune infiltration analysis revealed the prognositic value of myeloid dendritic cells, plasmacytoid dendritic cells, natural killer cells, macrophage M1, monocytes and hematopoietic stem cells in USs; the deep learning model named Max-Mean Non-Local multi-instance learning (MMN-MIL) showed satisfactory performance in predicting the survival of US patients, with the area under the receiver operating curve curve reached 0.909 and accuracy achieved 0.804.

CONCLUSION

USs harbored distinct gene fusion characteristics and gene expression features between HGESS, LGESS, and uLMS. The MMN-MIL model could effectively predict the survival of US patients.

Advancement in Multi-omics approaches for Uterine Sarcoma

Uterine sarcoma (US) is a rare malignant tumor that has various pathological types and high heterogeneity in the female reproductive system. Its subtle early symptoms, frequent recurrence, and resistance to radiation and chemotherapy make the prognosis for US patients very poor. Therefore, understanding the molecular mechanisms underlying tumorigenesis and progression is essential for an accurate diagnosis and targeted therapy to improve patient outcomes. Recent advancements in high-throughput molecular sequencing have allowed for a deeper understanding of diseases through multi-omics technologies. In this review, the latest progress and future potential of multi-omics technologies in US research is examined, and their roles in biomarker discovery and their application in the precise diagnosis and treatment of US are highlighted.

Rare Pathology Case Report: Low-Grade Endometrial Stromal Sarcoma Forming Sex Cord- and Endometrioid Gland-Like Differentiation in Metastatic Foci

Low-grade endometrial stromal sarcomas (LGESSs) are indolent tumors with a slow progression rate that tend to recur locally. They represent up to 10% of all primary sarcomas of the uterus and endometrium and only 0.2% of all genital tract tumors. They are commonly present in a younger demographic compared to other uterine tumors, with patients' ages typically between 42 and 58 years old. Although the overall 5-year survival rate is excellent, it has a natural history of delayed metastases which may manifest even decades after the disease was first diagnosed. They typically present as poorly defined lesions infiltrating the myometrium, along with extensive engagement of surrounding vascular structures. LGESS may display variants of different morphologies such as smooth muscle, fibromyxoid, sex cord-like, and endometrioid-type gland differentiation. These variations can pose a diagnostic challenge. The occurrence of this differentiation in a metastatic focus rather than in the primary tumor is seldom recorded in the literature. We present a case of a 51-year-old lady with a history of LGESS who was treated with surgery and radiotherapy and then presented after 12 years with an inferior vena cava (IVC) mass, which was confirmed histologically to be metastatic LGESS. Immunohistochemistry studies reveal strong positivity for CD10, WT1, and PR. These markers were negative in the sex cord and endometrioid gland-like differentiation counterparts. The patient had her initial follow-up appointment after the IVC mass resection, and she was in good health with no complications. To the best of our knowledge, this case represents a unique instance of metastatic LGESS exhibiting both sex cord and endometrioid gland-like differentiation that has not been observed in the primary tumor.

High-grade endometrial stromal sarcoma with BCOR rearrangements: clinicopathological analysis of five cases and literature reviews - an extension in understanding of morphological characteristics

Five cases of FISH verified BCOR rearranged high-grade endometrial stromal sarcoma were retrospectively analyzed. The patient age ranged from 33 to 65 years (median, 48.4 years). Most patients presented with irregular vaginal bleeding (3/5) and uterus mass (2/5). Only one patient developed an abdominal wall metastasis and other patients remained in good condition during the follow-up. Pathological findings revealed that the tumors exhibited morphological diversity in terms of cell shape, arrangement pattern and tumor stroma, compared to previous summarized histology of BCOR rearranged high-grade endometrial stromal sarcoma. Detailed description of such morphology changes expanded our understanding of the histology of BCOR rearranged high-grade endometrial stromal sarcoma. Due to the non-specificity of morphology in such malignancies, molecular testing is needed for confirmation in all patients.

Unexpected rare uterine carcinosarcoma with neuroendocrine differentiation: Reflections on clinical diagnosis and treatment of a case report

RATIONALE

Uterine carcinosarcoma (UCS) is a rare and highly invasive malignant tumor.It exhibits an ectopic growth pattern of the uterus,and its histological features are biphasic differentiation of malignant epithelial components (cancer) and malignant mesenchymal components (sarcoma). The pathological pattern of high-component neuroendocrine differentiation is extremely rare. Due to the inherent heterogeneity of tumors, it increases the difficulty of accurate identification and diagnosis. The author introduces a rare case of primary endometrial carcinosarcoma (heterologous) with small cell neuroendocrine carcinoma (SCNEC) components. There is limited literature on this rare pathological differentiation pattern and a lack of guidelines for the best treatment methods, which prompts reflection on the diagnosis, optimal treatment strategies, and how preoperative diagnosis can affect patient prognosis for endometrial carcinosarcoma with neuroendocrine differentiation.

PATIENT CONCERNS

The patient is an elderly woman who presents with abnormal vaginal bleeding after menopause. Transvaginal ultrasound examination shows that the uterus is slightly enlarged, and there is a lack of homogeneous echogenicity in the uterine cavity. Subsequently, a hysteroscopic curettage was performed, and a space-occupying lesion was observed on the anterior wall of the uterine cavity.

DIAGNOSES

Preoperative endometrial biopsy revealed SCNEC of the endometrium. The patient underwent radical hysterectomy, and the postoperative pathological results showed that UCS (heterologous) was accompanied by SCNEC components (about 80%).

INTERVENTION

The patient received radical hysterectomy, followed by adjuvant chemotherapy.

OUTCOME

After 7 months of follow-up, no tumor recurrence or metastasis was found at the time of writing this article.

LESSONS

The histological type of UCS (heterologous) with cell neuroendocrine carcinoma components is rare and highly invasive, with a high misdiagnosis rate in preoperative biopsy. There are currently no effective treatment guidelines for this type of case. The unusual appearance of SCNEC components in this case poses a challenge for both pathologists and surgeon. The rare differentiation pattern of this case exposes the complexity of its management and the necessity of prospective trials to determine the optimal treatment plan.

Trabectedin and Radiotherapy in Endometrial Stromal Sarcoma: A Case Report

Introduction

Endometrial stromal sarcoma (ESS) is a rare tumor that remains a diagnostic and therapeutic challenge to physicians worldwide. The metastatic setting implies a poor prognosis, with a 5-year survival rate below 40%. Patients with advanced-stage high-grade ESS (HG-ESS) have limited therapeutic options, often involving various chemotherapy regimens.

Case Presentation

This report depicts the case of a 47-year-old female diagnosed with HG-ESS. She underwent several lines of treatment starting with radiotherapy and brachytherapy, followed by multiple lines of treatment including trabectedin over several months. After retreatment with trabectedin and achieving disease stabilization for 10 months, treatment was optimized by trabectedin combined with radiotherapy, leading to stable disease that is still ongoing and lasts for over 17 months.

Conclusion

Our case underscores the challenging nature of treating patients with HG-ESS and highlights the safety of long-term retrial with trabectedin, coupled with radiotherapy administration. This approach maintained a durable stable disease response in the metastatic setting.

Oncogene-Induced Senescence Is a Crucial Antitumor Defense Mechanism of Human Endometrial Stromal Cells

Being the major cellular component of highly dynamic tissue, endometrial stromal cells (EnSCs) are exposed to cycles of proliferation upon hormonal stimulation, which might pose risks for the accumulation of mutations and malignization. However, endometrial stromal tumors are rare and uncommon. The present study uncovered defense mechanisms that might underlie the resistance of EnSCs against oncogenic transformation. All experiments were performed in vitro using the following methods: FACS, WB, RT-PCR, IF, molecular cloning, lentiviral transduction, and CRISPR/Cas9 genome editing. We revealed that the expression of the mutant HRASG12V leads to EnSC senescence. We experimentally confirmed the inability of HRASG12V-expressing EnSCs to bypass senescence and resume proliferation, even upon estrogen stimulation. At the molecular level, the induction of oncogene-induced senescence (OIS) was accompanied by activation of the MEK/ERK, PI3K/AKT, p53/p21WAF/CIP/Rb, and p38/p16INK4a/Rb pathways; however, inhibiting either pathway did not prevent cell cycle arrest. PTEN loss was established as an additional feature of HRASG12V-induced senescence in EnSCs. Using CRISPR-Cas9-mediated PTEN knockout, we identified PTEN loss-induced senescence as a reserve molecular mechanism to prevent the transformation of HRASG12V-expressing EnSCs. The present study highlights oncogene-induced senescence as an antitumor defense mechanism of EnSCs controlled by multiple backup molecular pathways.

Case Report: A case of COL1A1–PDGFB fusion uterine sarcoma at cervix and insights into the clinical management of rare uterine sarcoma

COL1A1–PDGFB gene fusion uterine sarcoma is an especially rare malignant mesenchymal tumor that was previously classified as an undifferentiated uterine sarcoma due to the lack of specific features of differentiation. Till now, only five cases have been reported, and here we presented another case recently diagnosed in a Chinese woman who had vaginal bleeding. She presented with a cervical mass at the anterior lip of the cervix invading the vagina and was treated with laparoscopic total hysterectomy plus bilateral salpingo-oophorectomy (TH+BSO) and partial vaginal wall resection with the final pathology of COL1A1–PDGFB fusion uterine sarcoma. Our aim is to emphasize the importance of differential diagnosis of this rare tumor, as early precise diagnosis may allow patients to benefit from the targeted therapy imatinib. This article also serves as further clinical evidence of this disease, serving to increase clinical awareness of this rare sarcoma to avoid misdiagnosis.

Case report: High-grade endometrial stromal sarcoma with adrenal glands metastases: An unreported site of metastasis

Background

Endometrial stromal sarcoma is a relatively rare malignant tumor that derives from the malignant transformation of primitive uterine mesenchymal cells. It can lead to distant metastases. High-grade endometrial stromal sarcoma is extremely rare. The adrenal glands are an unreported site of metastasis.

Case summary

A 71-year-old woman with a diagnosis of endometrial stromal sarcoma 30 months ago. After receiving treatment with radiotherapy and chemotherapy, the patient was kept asymptomatic during the follow-up until 2 years later, when she complained of dyspnea. Pulmonary and right adrenal gland metastases were detected by ¹⁸F-FDG PET/CT. The right upper lobe mass was diagnosed as a high-grade endometrial stromal sarcoma metastasis after postoperative pathology. Due to the patient's high risk of surgery, as she had many underlying diseases, we performed adequate preoperative preparation. The physical examination revealed that a hard mass was palpable in the right renal area. The right adrenal mass was resected in our hospital. Immunohistochemistry showed ER (-), PR (-), CD10 (+), P16 (+), Ki-67 (50%). The final diagnosis on pathological examination was a high-grade ESS metastatic to the right adrenal gland. The patient continued treatment in other hospitals after surgical resection. After four months of postoperative follow-up, metastasis was detected again during a PET/CT examination at an outside hospital.

Conclusion

Endometrial stromal sarcoma is rare, and the adrenal glands are an unreported site of metastasis. It has no specific clinical symptoms and mainly found for other reasons. The diagnosis still depends on pathology and immunohistochemistry. If there is no relevant past history, it is difficult to exclude a primary adrenal tumor.

Highly Invasive and Metastatic High-grade Endometrial Stromal Sarcoma With BCOR Gene Alterations: A Case Report

BACKGROUND

The coexistence of a uterine leiomyosarcoma and a high-grade endometrial stromal sarcoma (HGESS) is extremely rare, especially when one of the components causes metastasis.

CASE REPORT

A 46-year-old female with aggravated abdominal pain for more than 4 months was diagnosed with uterine malignant mesenchymal tumor composed of predominantly a leiomyosarcoma (99%) and a minor component of HGESS with BCL6 corepressor (BCOR) gene alterations (1%), with ovarian and pelvic metastases.

RESULTS

The volume of HGESS with BCOR gene alterations accounted for less than 1% of the tumor mass but caused ovarian and pelvic metastases.

CONCLUSION

HGESS with BCOR gene alterations is extremely aggressive. We suggest that when both components of HGESS with BCOR gene alterations and uterine leiomyosarcoma are present in one patient, the HGESS with BCOR gene alterations needs to be highlighted in the pathological report, even if it accounts for less than 1% of the tumor volume.