Recent advances in understanding and managing leiomyosarcomas

Stage IV uterine leiomyosarcoma resection: A case report

We present a case of stage IV uterine leiomyosarcoma that was treated with total hysterectomy, bilateral salpingo-oophorectomy, and extensive resection of a 14 kg abdominal mass, as well as complete eradication of accompanying symptoms. This case may prompt researchers to look for other surgical solutions to similar issues.

•

Stage IV Uterine Leiomyosarcoma can be surgically curable.

•

Total Hysterectomy and Bilateral Salpingo-Oophorectomy is the surgical choice in massive Uterine Leiomyosarcoma.

•

Post-operation Follow-ups with Ultrasonography at a 3-months intervals are crucial to detect early relapse.

Advanced Leiomyosarcoma of the Retroperitoneal Space in a Kidney Transplant Recipient with a History of Peritoneal Dialysis: A Case Report

Patient: Female, 44-year-old

Final Diagnosis: Leiomyosarcoma • liver metastases

Symptoms: Abdominal pain

Medication:—

Clinical Procedure: Biopsy

Specialty: Nephrology • Oncology • Transplantology

Histone deacetylase (HDAC) 9: versatile biological functions and emerging roles in human cancer

BACKGROUND

HDAC9 (histone deacetylase 9) belongs to the class IIa family of histone deacetylases. This enzyme can shuttle freely between the nucleus and cytoplasm and promotes tissue-specific transcriptional regulation by interacting with histone and non-histone substrates. HDAC9 plays an essential role in diverse physiological processes including cardiac muscle development, bone formation, adipocyte differentiation and innate immunity. HDAC9 inhibition or activation is therefore a promising avenue for therapeutic intervention in several diseases. HDAC9 overexpression is also common in cancer cells, where HDAC9 alters the expression and activity of numerous relevant proteins involved in carcinogenesis.

CONCLUSIONS

This review summarizes the most recent discoveries regarding HDAC9 as a crucial regulator of specific physiological systems and, more importantly, highlights the diverse spectrum of HDAC9-mediated posttranslational modifications and their contributions to cancer pathogenesis. HDAC9 is a potential novel therapeutic target, and the restoration of aberrant expression patterns observed among HDAC9 target genes and their related signaling pathways may provide opportunities to the design of novel anticancer therapeutic strategies.

Enhancing Proteotoxic Stress in Leiomyosarcoma Cells Triggers Mitochondrial Dysfunctions, Cell Death, and Antitumor Activity in vivo

Leiomyosarcomas are rare and aggressive tumors characterized by a complex karyotype. Surgical resection with or without radiotherapy and chemotherapy is the standard curative treatment. Unfortunately, a high percentage of leiomyosarcomas recurs and metastasizes. In these cases, doxorubicin and ifosfamide represent the standard treatment but with low response rates. Here, we evaluated the induction of proteotoxic stress as a possible strategy to kill leiomyosarcoma cells in a therapeutic perspective. We show that aggressive leiomyosarcomas coexist with high levels of proteotoxic stress. As a consequence, we hypothesized that leiomyosarcoma cells are vulnerable to further increases of proteotoxic stress. The small compound 2c is a strong inducer of proteotoxic stress. In leiomyosarcoma cells, it triggers cell death coupled to a profound reorganization of the mitochondrial network. By using stimulated emission depletion microscopy, we have unveiled the existence of DIABLO/SMAC clusters that are modulated by 2c. Finally, we have engineered a new version of 2c linked to polyethylene glycol though a short peptide, named 2cPP. This new prodrug is specifically activated by proteases present in the tumor microenvironment. 2cPP shows a strong antitumor activity in vivo against leiomyosarcomas and no toxicity against normal cells.

Report of the National Cancer Institute and the Eunice Kennedy Shriver National Institute of Child Health and Human Development-sponsored workshop: gynecology and women's health-benign conditions and cancer

The Division of Cancer Prevention and the Division of Cancer Biology at the National Cancer Institute and the Gynecologic Health and Disease Branch in the National Institute of Child Health and Human Development organized a workshop in April 2019 to explore current insights into the progression of gynecologic cancers from benign conditions. Working groups were formed based on 3 gynecologic disease types: (1) Endometriosis or Endometrial Cancer and Endometrial-Associated Ovarian Cancer, (2) Uterine Fibroids (Leiomyoma) or Leiomyosarcoma, and (3) Adenomyosis or Adenocarcinoma. In this report, we highlight the key questions and current challenges that emerged from the working group discussions and present potential research opportunities that may advance our understanding of the progression of gynecologic benign conditions to cancer.

Identification of Genetic Alterations by Circulating Tumor DNA in Leiomyosarcoma: A Molecular Analysis of 73 Patients

Background

Leiomyosarcoma is a malignant mesenchymal tumor of cells of smooth muscle lineage arising commonly in retroperitoneum, uterus, large veins, and the limbs. The genetics of leiomyosarcomas are complex and there is very limited understanding of common driver mutations. Circulating tumor DNA (ctDNA) offers a rapid and noninvasive method of next-generation sequencing (NGS) that could be used for diagnosis, therapy, and detection of recurrence.

Methods

ctDNA testing was performed using Guardant360, which detects single nucleotide variants, amplifications, fusions, and specific insertion/deletion mutations in 73 genes using NGS.

Results

Of 73 patients, 59 were found to have one or more cancer-associated genomic alteration. Forty-five (76%) were female with a median age of 63 (range, 38-87) years. All samples were designated metastatic. The most common alterations were detected in Tp53 (65%), BRAF (13%), CCNE (13%), EGFR (12%), PIK3CA (12%), FGFR1 (10%), RB1(10%), KIT (8%), and PDGFRA (8%). Some of the other alterations included RAF1, ERBB2, MET, PTEN TERT, APC, and NOTCH1. Potentially targetable mutations, by Food and Drug Administration-approved or clinical trials, were found in 24 (40%) of the 73 patients. Four patients (5%) were found to have incidental germline TP53 mutations.

Conclusion

NGS of ctDNA allows identification of genomic alterations in plasma from patients with leiomyosarcoma. Unfortunately, there is limited activity of current targeted agents in leiomyosarcomas. These results suggest opportunities to develop therapy against TP53, cell cycle, and kinase signaling pathways. Further validation and prospective evaluation is warranted to investigate the clinical utility of ctDNA for patients with leiomyosarcoma.

Different class IIa HDACs repressive complexes regulate specific epigenetic responses related to cell survival in leiomyosarcoma cells

Transcriptional networks supervising class IIa HDAC expression are poorly defined. Here we demonstrate that MEF2D is the key factor controlling HDAC9 transcription. This control, which is part of a negative feed-back loop during muscle differentiation, is hijacked in cancer. In leiomyosarcomas the MEF2D/HDAC9 vicious circuit sustains proliferation and cell survival, through the repression of the death receptor FAS. Comprehensive genome-wide studies demonstrate that HDAC4 and HDAC9 control different genetic programs and show both specific and common genomic binding sites. Although the number of MEF2-target genes commonly regulated is similar, only HDAC4 represses many additional genes that are not MEF2D targets. As expected, HDAC4-/- and HDAC9-/- cells increase H3K27ac levels around the TSS of the respective repressed genes. However, these genes rarely show binding of the HDACs at their promoters. Frequently HDAC4 and HDAC9 bind intergenic regions. We demonstrate that these regions, recognized by MEF2D/HDAC4/HDAC9 repressive complexes, show the features of active enhancers. In these regions HDAC4 and HDAC9 can differentially influence H3K27 acetylation. Our studies describe new layers of class IIa HDACs regulation, including a dominant positional effect, and can contribute to explain the pleiotropic actions of MEF2 TFs.

Rare Epstein-Barr Virus-Associated Smooth Muscle Tumor in a Patient with AIDS: A Case Report

CASE

A 34-year-old man with poorly controlled acquired immune deficiency syndrome underwent excision of a left arm mass. The histopathologic workup identified the features of an Epstein-Barr virus-associated smooth muscle tumor (EBV-SMT). The patient was readmitted 5 months later for vomiting and found to have liver metastases that were confirmed to be EBV-SMT. Six months after discharge, there was no recurrence of the arm mass or increase in the size of the liver metastases.

CONCLUSION

Most commonly found in immunocompromised patients, EBV-SMTs are rare tumors that can be mistaken for a leiomyosarcoma.

Leiomyosarcoma: Prognostic outline of a rare head and neck malignancy

Soft tissue sarcomas (STS) are mesenchymal malignant neoplasms with a broad spectrum of biologic behaviour. Most STS show predilection for extremities with rarity in head and neck. Leiomyosarcoma (LMS) is an extremely rare STS in head and neck due to the paucity of smooth muscles in this anatomical region. Owing to its rarity, diagnosis of LMS is often delayed or is often misdiagnosed. Our study aimed to evaluate clinico-demographic factors determining clinical course of primary head-neck LMS. Further, we also assessed cases of secondary head-neck LMS and LMS due to other causes to compare their clinical outcome with primary head-neck LMS. In primary LMS cases, intraoral LMS showed slightly better prognosis than extraoral LMS. Survival analysis revealed that prognosis of primary LMS was significantly better than secondary LMS. No significant difference in survival was seen between primary LMS and LMS due to other causes. These observations indicate that site of origin appears to determine the clinical behaviour of LMS. Results showed that size, recurrence and metastasis are important prognostic variables. Though large tumor size was associated with poor prognosis, tumor aggressiveness may not be directly proportional to its size. Surgical management with or without adjuvant therapy was associated with favourable outcome. As several factors are associated with prognostic outcome of head-neck LMS, multimodality therapy approach after careful analysis of various prognostic variables in each case on an individual basis is essential.

The Usefulness of Immunohistochemistry in the Differential Diagnosis of Lesions Originating from the Myometrium

Uterine leiomyomas (LMs), currently the most common gynecological complaint around the world, are a serious medical, social and economic problem. Accurate diagnosis is the necessary prerequisite of the diagnostic-therapeutic process. Statistically, mistakes may occur more often in case of disease entities with high prevalence rates. Histopathology, based on increasingly advanced immunohistochemistry methods, is routinely used in the diagnosis of neoplastic diseases. Markers of the highest sensitivity and specificity profiles are used in the process. As far as LMs are concerned, the crux of the matter is to identify patients with seemingly benign lesions which turn out to be suspicious (e.g., atypical LM) or malignant (e.g., leiomyosarcoma (LMS)), which is not uncommon. In this study, we present the current state of knowledge about the use of immunohistochemical markers in the differential diagnosis of LM, atypical LM, smooth muscle tumors of uncertain malignant potential (STUMP), and LMS, as well as their clinical predictive value.

Multiple Epstein-Barr Virus-associated Smooth Muscle Sarcomas of the Gut in a Child Treated for Acute Lymphoblastic Leukemia

A 7-year-old boy with a history of low-risk acute lymphoblastic leukemia developed multiple intussusceptions shortly after the end of maintenance therapy. Explorative laparotomy showed >10 polyps in the small intestine. Histologic examination revealed intestinal smooth muscle sarcomas associated with Epstein-Barr virus. The patient recovered well after partial cuneiform resection of the largest polyps and treatment with sirolimus. This case report indicates that these tumors may arise even after moderate transient immunosuppression and that association with acute lymphoblastic leukemia is possible although rarely described. We discuss the potential benefit of the mTor/Akt signal inhibitors as treatment for these tumors.

Laparoscopic surgery to treat leiomyosarcomas of the sigmoid colon:a case report and literature review

Background

Leiomyosarcomas (LMSs) of the colon are extremely rare and highly aggressive. Although treatment of gastrointestinal LMS is not standardized, surgical resection is generally performed. The fact that the tumors are usually large at the time of diagnosis may explain why no report on laparoscopic resection of a colonic LMS has appeared.

Case presentation

A 46-year-old male presented with hematochezia 1 month in duration. Abdominal examination including palpation was normal. The levels of several blood tumor markers were normal. Colonoscopy revealed a polypoid lesion approximately 30 mm in diameter in the sigmoid colon 30 cm from the anal verge. Contrast-enhanced computed tomography revealed that the tumor was 28 mm in diameter, and that no lymph node or distant metastasis was apparent. Histopathological examination of a biopsy specimen revealed spindle-shaped cells exhibiting significant nuclear atypia and a trabecular proliferation pattern upon hematoxylin-eosin staining. Immunohistochemically, the sample was positive for SMA and desmin, and negative for c-kit, DOG-1, CD34, and S-100. Furthermore, the Ki-67 index was > 50%. We thus diagnosed a leiomyosarcoma of the sigmoid colon without any metastasis. We performed laparoscopic sigmoid colectomy and regional lymphadenectomy using five trocars. After complete curative resection, a colorectal end-to-end anastomosis was created employing the double-stapling technique. All surgical margins were negative, and no lymph node metastasis was observed. The postoperative course was uneventful, and the patient was discharged 9 days after operation. No recurrence was noted to 1 year after surgery.

Conclusions

We report the first case of a colonic LMS treated via laparoscopic surgery. Although further work is necessary to assess prognosis and to develop the treatment further, laparoscopic surgery to treat small colonic LMSs may be feasible, being both minimally invasive and curative.

Review of the literature laparoscopic surgery for metastatic hepatic leiomyosarcoma associated with smooth muscle tumor of uncertain malignant potential: Case report

Metastatic hepatic leiomyosarcoma is a rare malignant smooth muscle tumor. We report a case of metastatic hepatic leiomyosarcoma associated with smooth muscle tumor of uncertain malignant potential (STUMP). A 68-year-old female presented with a liver mass (60 mm × 40 mm, Segment 4). She underwent left salpingo-oophorectomy for an ovary tumor with STUMP in a broad ligament 6 years ago. Though FDG-PET showed obvious metabolically active foci, abnormal metabolically active foci other than the lesion were not detected. A malignant liver tumor was strongly suspected and laparoscopic partial liver resection was performed with vessel-sealing devices using the crush clamping method and Pringle maneuver. Immunohistochemical findings revealed metastatic liver leiomyosarcoma associated with STUMP in a broad ligament. This case is an extremely rare case of malignant transformation from primary STUMP to metastatic hepatic leiomyosarcoma. It provides important evidence regarding the treatment for metastatic hepatic leiomyosarcoma associated with STUMP.

Increased infiltration of M2-macrophages, T-cells and PD-L1 expression in high grade leiomyosarcomas supports immunotherapeutic strategies

Background: Immunotherapy may be a rational strategy in leiomyosarcoma (LMS), a tumor known for its genomic complexity. As a prerequisite for therapeutic applications, we characterized the immune microenvironment in LMS, as well as its prognostic value. Methods: CD163⁺ macrophages, CD3⁺ T-cells, PD-L1/PD-L2 and HLA class I expression (HCA2, HC10 and β2m) were evaluated using immunohistochemistry in primary tumors (n = 75), local relapses (n = 6) and metastases (n = 19) of 87 LMS patients, as well as in benign leiomyomas (n = 7). Correlation with clinicopathological parameters and survival analyses were assessed. Effect of LMS cells on macrophage differentiation was investigated using coculture of CD14⁺ monocytes with LMS cell lines or their conditioned media (CM). Results: 58% and 52% of the tumors were highly infiltrated with CD163⁺ macrophages and T-cells, respectively, with HLA class I expression observed in almost all tumors and PD-L1 expression in 30%. PD-L2 expression was also detected in some PD-L1⁺ tumors. All these immune markers correlated with high tumor grade but only CD163 associated with overall survival (p = 0.003) and disease-specific survival (p = 0.041). In vitro, CD163 was upregulated in the presence of LMS cells producing M-CSF, suggesting that this tumor drives macrophages towards the M2 phenotype. Conclusion: The clinical significance of M2 macrophages, possibly induced by LMS cell-secreted factors, suggests that 2/3 of high-grade LMS patients might benefit from macrophage-targeting agents. Furthermore, PD-L1 expression together with high T-cell infiltrate and HLA class I expression in around 30% of high grade LMS reflects an active immune microenvironment potentially responsive to immune checkpoint inhibitors.

Transanal total mesorectal excision for a large leiomyosarcoma at the lower rectum: a case report and literature review

BACKGROUND

Rectal leiomyosarcoma (LMS) is an extremely rare disease. Previously, LMS was not properly distinguishable from gastrointestinal stromal tumor (GIST) until c-kit, a characteristic marker of GIST, was discovered in 1998. No standard therapeutic strategy for gastrointestinal LMS has been established except for surgical resection because of its rarity. Rectal LMS is often accompanied by symptoms, which can enable detection at a small size. However, when a large LMS is detected at the lower rectum, it is difficult to excise due to the narrow pelvic space.

CASE PRESENTATION

We present the case of an 86-year-old man with a large LMS. The LMS was asymptomatic and incidentally found at the lower rectum when he visited another hospital for management of benign prostatic hypertrophy. An abdominoperineal resection of the rectum was performed with combined resection of both seminal vesicles and a part of the prostate because tumor invasion was suspected. We used the hybrid method of laparoscopic and transanal total mesorectal excision (TaTME) approaches to achieve negative surgical margins. Late-onset urethral injury occurred in the postoperative course, which was successfully treated with a urethral catheter. The patient was discharged and received no adjuvant therapy. Local recurrence did not occur, but multiple lung metastases were detected 4 months later and the patient died 12 months after the surgery.

CONCLUSIONS

This is the first report of the hybrid method of laparoscopic and TaTME approaches to remove a large LMS at the lower rectum.