Leiomyosarcoma Patients Research Articles

Gemcitabine combined with docetaxel precisely regressed a recurrent leiomyosarcoma peritoneal metastasis in a patient-derived orthotopic xenograft (PDOX) model

There are no effective treatments for leiomyosarcoma (LMS) spreading intraabdominally. The aim of this study was to develop precision chemotherapy for recurrent peritoneal LMS metastases in a patient-derived orthotopic xenograft (PDOX) model. The LMS PDOX models were established orthotopically on the dome of the bladder of nude mice. The LMS PDOX models were randomized into 6 groups when the tumor volume reached 80 mm3: G1: untreated control; G2: doxorubicin (DOX) (DOX: i.p., 3 mg/kg, weekly, 3 weeks); G3: DOX combined with olaratumab (OLA) (DOX: i.p., 3 mg/kg, weekly, 3 weeks; OLA: i.p., 40 mg/kg, 3 times/week, 3 weeks); G4: gemcitabine (GEM) combined with docetaxel (DOC) (GEM: i.p., 100 mg/kg, weekly, 3 weeks; DOC: i.p., 20 mg/kg, weekly, 3 weeks); G5: pazopanib (PAZ) (PAZ: p.o., 100 mg/kg, daily, 3 weeks); G6: palbociclib (PAL) (PAL: p.o., 100 mg/kg, daily, 3 weeks). All mice were sacrificed on day 22. Body weight was assessed twice a week. Tumor volume was measured on day 0 and day 22. Although all regimens had a significant efficacy compared to the untreated group (P < 0.001), only GEM combined with DOC regressed the tumor significantly (P < 0.001), suggesting GEM combined with DOC has clinical potential for this LMS patient.

MRI screening for uterine leiomyosarcoma.

Uterine fibroids are a common benign tumor and can be symptomatic, necessitating resection. Surgical myomectomy is an effective treatment option with a risk of disseminating occult uterine leiomyosarcoma (LMS), creating a need for an effective presurgical screening protocol. Clinical collaboration with contrast-enhanced MRI including T2 and diffusion-weighted imaging (DWI) can be utilized as a screening exam. To review the accuracy and feasibility of an interdisciplinary prospective contrast-enhanced MRI pelvis with DWI screening system for LMS prior to fibroid resection. Retrospective cohort study. In all, 1960 adult female patients aged 18-87 undergoing screening MRI pelvis prior to uterine fibroid resection. T1 and T2 -weighted imaging, DWI, and contrast-enhanced images were acquired at 1.5 T and 3.0 T. Each radiologist at the time of clinical study prospectively designated a confidence level of presence of LMS in the impression, which was reviewed retrospectively. A separate retrospective evaluation of the histologically proven LMS and the false positives was performed for the presence of five MRI features of LMS including low ADC values, intermediate/high T2 signal intensity, irregular margins, hemorrhage, and necrosis. A preliminary cost-effectiveness analysis was performed, comparing the costs of treatment of uterine fibroids with vs. without a collaborative screening protocol using MRI. Sensitivity, specificity, positive predictive value, and negative predictive value were obtained from the prospective evaluations. Student's t-tests were used to compare demographics and apparent diffusion coefficient values between LMS and false-positive results. We prospectively identified LMS patients with 100% sensitivity and 97% specificity. Preliminary cost analysis demonstrated that the MR screening protocol increased life expectancy by 0.04 years at a cost of $12,937 per life-year gained. MRI is an effective and potentially economic screening test, especially with standardized reporting and coordination with clinicians. 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019.

Cervical leiomyosarcoma treated by radical laparoscopic approach: a case report

Cervical sarcomas are extremely rare neoplasms associated with younger age, advanced stage, and poorer prognosis relative to cervical carcinomas. Carcinosarcoma is the most frequently observed cervical sarcoma subtype, while leiomyosarcomas are exceedingly rare subtypes, with only a small number of cases reported in the English language literature. Cervical leiomyosarcoma patients present most commonly with abnormal vaginal bleeding, discharge, and/or abdominal and pelvic pain. Due to their rarity, data regarding these tumors typically come from case reports and small case series, and treatment strategies are often adapted from data for uterine sarcomas. Here the authors report the clinical findings from a case of unusual asymptomatic leiomyosarcoma arising in the uterine cervix and treated with a laparoscopic approach.

Surgery plus chemotherapy improves survival of patients with extremity soft tissue leiomyosarcoma and metastasis at presentation.

Purpose: Extremity soft tissue leiomyosarcoma (LMS) with metastasis is a rare disease with a poor prognosis. The purpose of our study was to define clinical features of extremity soft tissue LMS with metastasis as well as to identify multivariable predictors of survival.Methods: During 1973-2015, 239 patients with metastatic extremity soft tissue LMS were identified from the Surveillance, Epidemiology, and End Results (SEER) program database. The prognostic analysis was performed using the Kaplan-Meier method and a Cox proportional hazards regression model.Results: This group comprised 126 females (52.7%) and 113 males (47.3%), whose ages ranged from 8 to 95 years (median 67 years). The overall survival (OS) and cancer-specific survival (CSS) rates of the entire group at 3 years were 22.6% and 23.4%, respectively. The median OS and CSS were 14.0±1.5 and 15.0±2.3 months, respectively. Multivariate analysis revealed that tumor size >10 cm, no surgery and no chemotherapy were independent risk factors of decreased OS and CSS. Radiotherapy was not significantly associated with OS or CSS.Conclusion: Extremity soft tissue LMS patients who present with metastasis at diagnosis had a poor prognosis. Patients who performed surgery for primary tumors and chemotherapy had a better chance for prolonged survival.

Incidence and groups at risk for unexpected uterine leiomyosarcoma: a Dutch nationwide cohort study

ObjectiveTo estimate the risk of uterine leiomyosarcoma in patients undergoing gynecological surgery and also to identify groups at risk for unrecognized uterine leiomyosarcoma.MethodsA national cohort study was performed evaluating all uterine leiomyosarcoma (ULMS) diagnosed in The Netherlands between January 2000 and September 2015. Cases were identified and supplied by the nationwide network and registry of histo- and cytopathology in The Netherlands (PALGA). Unexpected and expected ULMS were compared. Approval for this study was granted by the Medical Ethics Committee of all participating hospitals and by the review board of PALGA.Results262 original cases were included. The overall incidence of ULMS in our study was 0.25% or 1:400 patients. The incidence of unexpected ULMS was 0.12% or 1:865 patients. Preoperatively, a malignancy was unexpected in 46% of the cases and expected in 54%. Abnormal uterine bleeding constituted most of the symptoms. 90% of women underwent abdominal hysterectomy and/or bilateral salpingo-oophorectomy.ConclusionsLeiomyosarcoma are rare. Women aged 40–50 years with abnormal uterine bleeding are most at risk for unexpected ULMS. In contrast, this risk is low in postmenopausal women. ULMS were highly uncommon in women aged under 40 years.

Surgical resection for recurrent retroperitoneal leiomyosarcoma and liposarcoma

BackgroundRetroperitoneal soft tissue sarcomas (STS) include a number of histologies but are rare, with approximately 3000 cases in the USA per year. Retroperitoneal STS have a high incidence of local and distant recurrence. The purpose of this study was to review the University of Maryland Medical Center’s (UMMC) treatment experience of retroperitoneal STS, where the patient population served represents a diverse socioeconomic and ethnic catchment.MethodsIRB approval was obtained. We constructed a de-identified database of patients diagnosed with retroperitoneal liposarcomas (LPS) or leiomyosarcomas (LMS) treated at UMMC between 2000 and 2013. A total of 49 patients (Pts) with retroperitoneal STS met our eligibility criteria. Kaplan-Meier plots were used to graphically portray progression-free survival (PFS) and overall survival (OS). The log-rank test was used to compare time-to-event distributions.ResultsThe median OS for all patients (Pts) was 6.3 years, and the 2-year OS rate was 81%. The median PFS for all Pts was 1.8 years, and the 2-year PFS rate was 45%. There was no difference in OS and PFS among LMS and LPS patients; the median OS for LMS was 3.8 years vs. LPS 6.4 years (p = 0.33), and the median PFS for LMS was 1.2 years vs. LPS 2.5 years (p = 0.28). There was a significant difference between histology and race (p = 0.001). LPS were primarily Caucasian 86% vs. 14% black, whereas LMS were primarily black 52% vs. 33% Caucasian. OS was influenced by functional status, gender, American Joint Committee on Cancer (AJCC) stage, grade, histology, tumor size, and extent of resection. PFS was influenced by AJCC stage, grade, and extent of resection. Neither adjuvant chemotherapy (1 Pt) nor neoadjuvant/adjuvant radiation therapy (18 Pts) influenced OS or PFS. There was a non-significant difference that Pts who could undergo resection of local recurrence had improved 2-year OS, with 100% LMS and LPS compared to 2-year OS of 71% (LMS) and 78% (LPS) not undergoing resection of local recurrence.ConclusionsThis study suggests a higher incidence of leiomyosarcoma in the African-American population. This study confirms the prognostic importance of grade, tumor size, AJCC stage, histology, and extent of resection in patient outcomes, at a large substantially diverse academic medical center. Future research into the biological features of liposarcoma and leiomyosarcoma Pts imparting these characteristics will be important to define.

Intratumoral immune-biomarkers and mismatch repair status in leiyomyosarcoma -potential predictive markers for adjuvant treatment: a pilot study.

Leiomyosarcoma is the second most frequent soft-tissue sarcoma. Tumor lymphocytic infiltration (TIL) and programed cell death ligand-1 (PD-L1) have been associated with prognosis in different malignancies while DNA mismatch-repair deficiency (MMR-D) has been associated with response to check-point inhibitors. In this pilot study, we sought to examine TIL, PD-L1 and mismatch-repair (MMR) protein expression in 11 leiomyosarcoma and its association with outcome as potential biomarkers for adjuvant treatment.Eleven primary leiomyosarcoma archived-tissues were analyzed for expression of MMR proteins (MSH2, MLH1, MSH6 and PSM2), PD-L1 expression and PD-1, CD3 or CD8.MMR-D was detected in tumor tissue from 2/11 leiomyosarcoma patients. CD3 T-cells were present in all samples, whereas CD8 staining was positive in all but one. PDL-1 was positive in 4/11 and PD-L1 in 6/11. Interestingly, the three patients with the poorest outcome had strongly positive staining for PD-L1 and CD8 while in the two patients who are alive and recurrence-free, both PD-L1 and CD8 infiltration were lacking.We found an association between tumor infiltrating CD8 cytotoxic lymphocytes, strong PD-L1 staining and survival; suggesting a role as biomarkers for treatment decisions regarding peri-operative chemotherapy. We also identified MMR-D in two patients with leiomyosarcoma comprising 18% of our sample.

Prognostic factors analysis of Ki-67, α-SMA expression in retroperitoneal leiomyosarcoma

Objective: To investigate the expression and prognostic value of alpha smooth muscle actin(α-SMA) and Ki-67 in retroperitoneal leiomyosarcoma. Methods: Fifty retroperitoneal leiomyosarcoma patients who underwent operation in Chinese People's Liberation Army General Hospital from May 2002 to December 2015 were retrospectively analyzed. There were 14 males and 36 females form 21 to 79 and an average age of 48. Kaplan-Meier estimations and Cox regression analyses were performed. Results: Of the 50 cases, 45 patients underwent complete resection, and others are not. The overall 1, 3, 5-year survival rates were 86.0%, 46.0% and 28.0%, respectively. Tumor size, extent of resection, pathological stage, and expression levels of Ki-67 and alpha smooth muscle actin (α-SMA) were closely related to the survival of retroperitoneal leiomyosarcoma patients (all P<0.05), respectively. Multivariate analysis showed that pathological grade and degree of surgical resection were independent risk factors in the prognosis of patients (P<0.05). Conclusion: The high expression of α-SMA and Ki-67 are indicators of poor prognosis in retroperitoneal leiomyosarcoma, which can be used as a potential survival predictor in patients with retroperitoneal leiomyosarcoma.

EXPRESSION OF MMP-9 AS A PROGNOSTIC FACTOR OF UTERINE SARCOMA

Uterine sarcoma is a highly aggressive mesenchymal neoplasm with an extremely unfavorable prognosis. Up today there are still relevant issues concerning search for clinical-morphological and biomolecular criteria for prognosis relapse-free survival of uterine sarcoma patients. It is well-known, the increase of the expression level of MMP-9 in primary tumor or metastatic foci correlates with a low differentiation of tumor cells, high ability for invasiveness, high metastatic activity, and shortened life expectancy. It’s still unknown, whether it is possible to consider the expression of MMP-9 in uterine sarcoma cells as a convincing prognostic factor. For many types of epithelial malignant neoplasms, high metastatic rate is associated with an increase level of MMP-9 both in plasma and in tumor tissue. The purpose of this study is to investigate the features of MMP-9 expression in uterine sarcoma cells for development of the model for individual prediction of the disease course. The study of the surgical material of selected 54 cases of uterine sarcoma of stage I-II (according to FIGO criteria) with a known prognosis of the disease, which were distributed depending on the morphological type done: leiomyosarcoma (LMS) – 18 cases, endometrial stromal sarcoma (ESS) - 22 cases, undifferentiated sarcoma (US) – 14 (according to the classification of tumors of the uterus of the WHO). For histological examination, pieces of tissue were cut from different parts of the tumor nodes – central, peripheral, parts of the adjacent intact tissue of myometrium (total of 6-8 bits). The tumor cell phenotype was determined using low molecular weight cytokeratins (Cytokeratin PAN, AE1 / AE3), smooth muscle actin (Smooth Muscle Actin, 1A4), myogenin (Myogenin (F5D)), CD 10 and vimentin (Vimentin, V9). The histochemical label was evaluated in two parameters: the degree of prevalence and intensity of coloration. To assess the color intensity, a qualitative scale was used: 0 – no reaction, 1+ – weak cytoplasmic coloration to 30.0% of tumor cells, 2+ – moderate reaction, 30.0 to 60.0% of stained cells, 3+ – pronounced cytoplasmic reaction in 60,0-100,0% of tumor cells. Statistical processing of the data was performed using the “STATISTICA 10.0” program package. The conducted study has showed, the negative (0) and weak (1+) expression of matrix metalloproteinase-9 were observed in the most part of ESS and only partially in US. Despite the stage of the disease, with such a status of MMP-9, there was observed no signs of relapsed disease. The moderate (2+) and high (3+) expression of MMP-9 was detected in 44.5 % of uterine sarcoma, in the most part in LMS patients. However, if in LMS cases the progressive disease was observed only in one third of them (4 of 12 cases), in case of ESS and US, in all the patients with such tumors status there was observed relapsed disease. Such a reaction may be indicative for invasive and metastatic potential of ESS and US and cause of the hematogenous metastases.

Abstract A05: Circulating tumor DNA levels correlate with response to treatment in LMS patients

Abstract Circulating tumor DNA (ctDNA) has significant potential for several clinical applications, including assessment of treatment response and monitoring of recurrent/residual disease. We performed a pilot study to explore the feasibility of ctDNA monitoring in patients with leiomyosarcoma (LMS). We profiled matching plasma and FFPE tumor specimens from 9 LMS patients. We analyzed between 2 to 6 longitudinal plasma samples (median of 5) and between 1 to 7 tumor specimens (median of 2) per patient. ctDNA analysis was performed on plasma samples collected pre-/post-surgery, throughout chemo-/radiotherapy and during follow-up. We used two separate approaches in our study: 1) targeted deep sequencing of ctDNA, tumor DNA and germline DNA to detect single nucleotide variants and indels using Cancer Personalized Profiling by deep Sequencing with integrated digital error suppression (CAPP-Seq; with a median deduplicated depth of sequencing of 2,136x); 2) copy number variant analysis in ctDNA by genome representation profiling (GRP; median coverage across the whole genome 0.23x) and in the matched tumors by SNP arrays. One patient was excluded from the analysis due to inadequate sequencing coverage in tumor specimen. For CAPP-Seq analysis, we designed a custom 184kb capture panel targeting 89 genes that are recurrently mutated in LMS. Using strict variant calling criteria (requiring that variants be present on each strand of the original DNA “duplex” molecule) our panel identified a median of one nonsynonymous coding/splicing variant per tumor. We detected the same variants in TP53, RB1 and ATRX genes in ctDNA of 6/8 patients (with a baseline sensitivity of 87.5% and overall specificity of 98.96% calculated using plasma from 24 healthy donors). These six patients presented with advanced disease at the time of the first blood collection and were progressing throughout multiple lines of therapy. Two patients who did not have any variants detectable by CAPP-Seq in plasma had localized disease at the time of the first blood collection and/or responded well to the therapy. We found that changes in ctDNA levels appear to correspond with the extent of disease and response to treatment. Specifically, ctDNA levels decreased in a subset of patients after surgery or at the time of temporary response to chemo- and/or radiotherapy. Congruently, increases in ctDNA levels correlated with progression in most of the patients. There was a high correlation between ctDNA levels detected by CAPP-Seq (quantified as mutant molecules/mL plasma) and GRP (quantified as percent of genome showing copy number aberrations) across all plasma samples (Pearson's r= 0.88, p &amp;lt; 0.0001), but in a few samples ctDNA was detected by only one of the two assays. Our results suggest that serial analysis of ctDNA is a promising approach for evaluation of treatment response in LMS patients. Validation of these findings in a prospective study on a larger group of patients will be required to determine the use of this approach in a clinical setting.

Could leiomyosarcoma be a real concern for the gynecologist performing minimally-invasive surgery for uterine myoma?

Uterine leiomyosarcoma is a rare malignant tumor with a poor prognosis. The diagnosis of uterine sarcoma is often made after myomectomy or hysterectomy at the histologic examination. The differential diagnosis between leiomyosarcoma and uterine fibroids is difficult to establish preoperatively. Most cases of uterine fibroids can be treated minimally invasively, but extracting lar­ger specimens is an impediment to choosing this surgical method. The risks of morcellation (vascular or bowel injury, intraabdominal tissue dissemination) must be balanced against comorbidities related to laparatomy. In 2014, FDA warned that the prevalence of occult leiomyosarcoma in patients undergoing hysterectomy or myomectomy for presumed benign leiomyoma is 1 in 498 and discouraged the morcellation of uterine fibroids during laparoscopy. In order not to give up minimally-invasive surgery and to reduce the risks of morcellation, the use of endoscopic bags has been considered to avoid the spread of potentially malignant tissue. However, it is advisable not to use morcellator, even with the endoscopic bag, if there is a high suspicion of malignancy. We need to take into account the disadvantages of the method. In conclusion, uterine leiomyosarcoma continues to be a concern for gynecologists, given that until now there are no investigations to detect it preoperatively. The selection of patients with uterine fibroids for laparoscopy using the morcellation of the specimens should be rigorous.

Inflammatory leiomyosarcoma is a distinct tumor characterized by near-haploidization, few somatic mutations, and a primitive myogenic gene expression signature

Inflammatory leiomyosarcoma is a soft-tissue tumor resembling conventional leiomyosarcoma, but with a prominent intrinsic inflammatory component. Previous studies have suggested that inflammatory leiomyosarcoma differs genetically from leiomyosarcoma, but in-depth analyses are lacking. Here we provide a comprehensive picture of the genome and transcriptome of inflammatory leiomyosarcoma by combining cytogenetic, single-nucleotide polymorphism array, mRNA-sequencing, and whole-exome sequencing data. The results show that inflammatory leiomyosarcoma has a specific genetic profile characterized by near-haploidization with or without subsequent whole-genome doubling. Consistently, both parental copies of chromosomes 5 and 22 are preserved. Apart from recurrent mutation of the NF1 gene, additional somatic events that could serve as driver mutations were not found at either the nucleotide or the genome level. Furthermore, no fusion transcripts were identified. Global gene expression profiling revealed particularly prominent differential expression of genes, including ITGA7, MYF5, MYF6, MYOD1, MYOG, and PAX7, involved in muscle development and function, providing strong argument for grouping inflammatory leiomyosarcoma with myogenic sarcomas, rather than with myofibroblastic lesions. Combined with previously published data, there are now 10 cases of inflammatory leiomyosarcoma with confirmed near-haploid genotype. These patients differ from leiomyosarcoma patients in being younger (median 41 years), showing a male predominance (9:1), and few relapses (1 of 8 informative patients). Thus, the clinical, morphological, and genetic data provide compelling support for inflammatory leiomyosarcoma being a distinct subtype of myogenic tumors.

Mocetinostat combined with gemcitabine for the treatment of leiomyosarcoma: Preclinical correlates.

Leiomyosarcoma (LMS) is a malignant soft tissue sarcoma (STS) with a dismal prognosis following metastatic disease. Chemotherapeutic intervention has demonstrated to have modest clinical efficacy with no curative potential in LMS patients. Previously, we demonstrated pan-HDAC inhibition to have a superior effect in various complex karyotypic sarcomas. In this study, our goal is to evaluate the therapeutic efficacy of mocetinostat alone and in combination with gemcitabine in LMS. Human leiomyosarcoma (LMS) cell lines were used for in vitro and in vivo studies. Compounds tested included the class I HDAC inhibitor, mocetinostat, and nucleoside analog, gemcitabine. MTS and clonogenic assays were used to evaluate the effect of mocetinostat on LMS cell growth. Cleaved caspase 3/7 analysis was used to determine the effects of mocetinostat on apoptosis. Compusyn software was used to determine in vitro synergy studies for the combination of mocetinostat plus gemcitabine. A LMS xenograft model in SCID mice was used to test the impact of mocetinostat alone, gemcitabine alone and the combination of mocetinostat plus gemcitabine. Mocetinostat abrogated LMS cell growth and clonogenic potential, and enhanced apoptosis in LMS cell lines. The combination of mocetinostat plus gemcitabine exhibited a synergistic effect in LMS cells in vitro. Similarly, mocetinostat combined with gemcitabine resulted in superior anti-LMS effects in vivo. Mocetinostat reduced the expression of gemcitabine-resistance markers RRM1, RRM2, and increased the expression of gemcitabine-sensitivity marker, hENT1, in LMS cells. LMS are aggressive, metastatic tumors with poor prognosis where effective therapeutic interventions are wanting. Our studies demonstrate the potential utility of mocetinostat combined with gemcitabine for the treatment of LMS.

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

ABSTRACT 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.

Expression and role of TYRO3 and AXL as potential therapeutical targets in leiomyosarcoma

Background:Leiomyosarcoma (LMS) are 15% of adult sarcomas and remain seldom curable in metastatic phase. The TAM receptors and their ligands are overexpressed or activated in multiple malignancies, including LMS.Methods:The TAM receptor and ligand expression was evaluated in LMS cell lines and 358 sarcoma samples by either gene expression or immunohistochemistry. TYRO3 and AXL were knocked down. Crizotinib and foretinib were investigated in vitro.Results:High expression of TYRO3 and AXL was detected in LMS cell lines. TYRO3 or AXL gene knockdown reduced cell proliferation/colony formation. Crizotinib and foretinib decreased TYRO3 and AXL phosphorylation, apoptosis, G2/arrest and reduced colony formation. Immunohistochemistry performed in 107 sarcomas showed higher expression of TYRO3 and GAS6 in LMS vs other sarcomas and nuclear TYRO3 only in LMS. Microarray gene expression performed in 251 sarcomas revealed significantly higher expression of TYRO3 and GAS6 in LMS than other sarcomas. Leiomyosarcoma patients with high expression of GAS6 or PROS1 present a significantly worse PFS.Conclusions:Leiomyosarcoma patients, especially those whom develop metastasis, express higher levels of TYRO3 and GAS6. Crizotinib and foretinib showed effective antitumour activity in LMS through TYRO3 and AXL deactivation indicating that clinical trials using TYRO3 and AXL inhibitors are warranted in advanced LMS.

CDK4/6 Inhibitors Sensitize Rb-positive Sarcoma Cells to Wee1 Kinase Inhibition through Reversible Cell-Cycle Arrest.

Research into the biology of soft tissue sarcomas has uncovered very few effective treatment strategies that improve upon the current standard of care which usually involves surgery, radiation, and chemotherapy. Many patients with large (>5 cm), high-grade sarcomas develop recurrence, and at that point have limited treatment options available. One challenge is the heterogeneity of genetic drivers of sarcomas, and many of these are not validated targets. Even when such genes are tractable targets, the rarity of each subtype of sarcoma makes advances in research slow. Here we describe the development of a synergistic combination treatment strategy that may be applicable in both soft tissue sarcomas as well as sarcomas of bone that takes advantage of targeting the cell cycle. We show that Rb-positive cell lines treated with the CDK4/6 inhibitor palbociclib reversibly arrest in the G1 phase of the cell cycle, and upon drug removal cells progress through the cell cycle as expected within 6-24 hours. Using a long-term high-throughput assay that allows us to examine drugs in different sequences or concurrently, we found that palbociclib-induced cell-cycle arrest poises Rb-positive sarcoma cells (SK-LMS1 and HT-1080) to be more sensitive to agents that work preferentially in S-G2 phase such as doxorubicin and Wee1 kinase inhibitors (AZD1775). The synergy between palbociclib and AZD1775 was also validated in vivo using SK-LMS1 xenografts as well as Rb-positive patient-derived xenografts (PDX) developed from leiomyosarcoma patients. This work provides the necessary preclinical data in support of a clinical trial utilizing this treatment strategy. Mol Cancer Ther; 16(9); 1751-64. ©2017 AACR.

Establishment and proteomic characterization of NCC-LMS1-C1, a novel cell line of primary leiomyosarcoma of the bone

Leiomyosarcoma (LMS) is one of most aggressive mesenchymal malignancies that differentiate towards smooth muscle. The clinical outcome of LMS patients is poor; as such, there is an urgent need for novel therapeutic approaches. Experimental models such as patient-derived cell lines are invaluable tools for pre-clinical studies. In the present study, we established a stable cell line from the tumor tissue of a patient with a primary LMS of the bone. Despite the urgent need for novel therapeutic strategies in LMS, there are only a few LMS cell lines available in public cell banks, none of which are primary to the bone. Bone primary LMS tumor tissues were sampled to establish cell lines. Morphological and proteomic analyses were performed and sensitivity to pazopanib was evaluated. NCC-LMS1-C1 cells were maintained for over 100 passages. The cells exhibited a spindle shape and aggressive growth; they also expressed smooth muscle actin, reflecting the original LMS tissue (i.e. smooth muscle cells). The cells also showed tumor characteristics such as colony formation on soft agar and sensitivity to pazopanib, doxorubicin and cisplatin, with half-maximal inhibitory concentrations of 4.5, 0.11 and 20 μM, respectively. Proteomic analyses by mass spectrometry and antibody array revealed some differences in the protein expression profiles of these cells as compared to the original tumor tissue. Our results indicate that the NCC-LMS1-C1 cell lines will be useful for LMS research.

Overexpressed PRAME is a potential immunotherapy target in sarcoma subtypes

BackgroundPRAME (preferentially expressed antigen in melanoma), a member of the cancer-testis antigen family, has been shown to have increased expression in solid tumors, including sarcoma, and PRAME-specific therapies are currently in development for other cancers such as melanoma.MethodsTo map the landscape of PRAME expression in sarcoma, we used publicly available data from The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE) projects and determined which sarcoma subtypes and subsets are associated with increased PRAME expression. We also analyzed how PRAME expression correlates with survival and expression of markers related to antigen presentation and T cell function. Furthermore, tumor and normal tissue expression comparisons were performed using data from the genotype-tissue expression (GTEx) project.ResultsWe found that uterine carcinosarcoma highly overexpresses the PRAME antigen, and synovial sarcomas and multifocal leiomyosarcomas also show high expressions suggesting that PRAME may be an effective target of immunotherapies of these tumors. However, we also discovered that PRAME expression negatively correlates with genes involved in antigen presentation, and in synovial sarcoma MHC class I antigen presentation deficiencies are also present, potentially limiting the efficacy of immunotherapies of this malignancy.ConclusionsWe determined that uterine carcinosarcoma, synovial sarcoma, and leiomyosarcoma patients would potentially benefit from PRAME-specific immunotherapies. Tumor escape through loss of antigen presentation needs to be further studied.

Trabectedin for advanced soft tissue sarcoma: Ten-year real-life perspective.

11060 Background: Trabectedin is a marine - derived chemotherapy, which lately received FDA approval for use in anthracycline resistant advanced soft tissue sarcoma (STS), especially liposarcoma and leiomyosarcoma (L-sarcomas). Methods: We report our ten-year real-life experience with trabectedin, 1.5mg/m2/d c.i.v. q3w till progression, regarding safety and efficacy in a cohort of 86 patients (24-83y). Liposarcoma was the diagnosis in 46% , leiomyosarcoma in 43%. Results: A total of 703 cycles of Trabectedin were given, with a median of five cycles per patient (range 1-59). Median overall survival (mOS) was 11 months for liposarcoma patients (range 1-63), and 15 months for leiomyosarcoma patients (range 1-35). There was no statistically significant difference in progression free survival (PFS), when stratified according to previous treatment lines given. Trabectedin exhibited a favorable safety profile, with only 22% requiring dose reductions. Grade 3 and more toxicity were noted in 25% of the patients, mostly myelosuppression. There was no treatment related death. Conclusions: In contrast to former trials, our retrospective data represents real life experience with Trabectedin, and includes patients with diverse age, histology, performane status, prior treatments and tumor burden. The group includes 10 patients (11.6%) who received Trabectedin as first line (Either due to congestive heart failure or to rapid progression following adjuvant Doxorubicin and Ifosfamide), 10 patients (11.6%) were above age 70, nine (10.5%) had histologies other than liposarcoma or leiomyosarcoma, and 23 (26.7%) had ECOG PS of 2 or higher. Trabectedin is a safe and effective drug in advanced high grade STS. Further research is needed to identify which patients will benefit most.

Prevalence of Leiomyosarcoma Following Hysterectomy at a Single-Site Institution [22D

INTRODUCTION: The U.S. Food and Drug Administration (FDA) issued a statement in April 2014 discouraging the use of power morcellation in women undergoing minimally invasive surgery for uterine fibroids, citing safety concerns regarding the potential dissemination of an occult uterine cancer. While it is estimated that between 1 in 400 and 1 in 1,000 women who undergo hysterectomy for presumed benign fibroids will be diagnosed with leiomyosarcoma (LMS), it is difficult to conclude the actual risk of an occult sarcoma. The purpose of this study was to determine the prevalence of LMS in patients that have undergone hysterectomy at Stanford University Medical Center, and to include all surgical approaches in this analysis. METHODS: Patients undergoing hysterectomy for benign and malignant gynecologic indications from January 2009 to December 2014 at Stanford University Medical Center were identified. The mode of hysterectomy along with relevant clinical and pathologic data were collected for this retrospective cohort study. RESULTS: A total of 909 hysterectomies were identified. The majority were performed by an abdominal route (69%), followed by laparoscopic (17%), robotic-assisted (13%), and vaginal (1%). Two patients were identified with leiomyosarcoma and two with occult sarcoma. Of the laparoscopic and robotic hysterectomies, morcellation was used in 26 patients. Of these, three patients had known endometrial carcinoma and contained morcellation was performed. CONCLUSION: The prevalence of leiomyosarcoma was 0.0022 in our population. As part of a multi-institution study, the long-term goal would be to understand prevalence rates in a larger population and develop risk-stratification to minimize risks of developing LMS.