Diagnosis, prognosis, and management of leiomyosarcoma: recognition of anatomic variants

Pleomorphic leiomyosarcoma of the maxilla with metastasis to the colon: A case report

BACKGROUND

Pleomorphic leiomyosarcomas make up around 8.6% of all leiomyosarcomas. They behave aggressively and often have poor prognoses. They can affect the gastrointestinal tract and retroperitoneum. To date, pleomorphic leiomyosarcoma involving the mesocolon have been reported in nine patients.

CASE SUMMARY

The patient was a 44-year-old man with a history of pleomorphic leiomyosarcoma of the left maxilla with metastasis to the lung and liver. His most recent positron emission tomography-computed tomography (PET-CT) scan showed uptake in the ascending and transverse colons. A colonoscopy revealed a 5.0 cm × 3.5 cm × 3.0 cm pedunculated polyp in the ascending colon. The polyp was removed using hot snare polypectomy technique and retrieved with Rothnet. Histopathologic examination of the polyp showed a metastatic pleomorphic leiomyosarcoma.

CONCLUSION

Uptake(s) on PET-CT in a patient with pleomorphic leiomyosarcoma should raise suspicion for metastasis.

Prediction of 5-year survival in soft tissue leiomyosarcoma using a machine learning model algorithm

BACKGROUND AND OBJECTIVES

Leiomyosarcoma (LMS) is associated with one of the poorest overall survivals among soft tissue sarcomas. We sought to develop and externally validate a model for 5-year survival prediction in patients with appendicular or truncal LMS using machine learning algorithms.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used for development and internal validation of the models; external validation was assessed using our institutional database. Five machine learning algorithms were developed and then tested on our institutional database. Area under the receiver operating characteristic curve (AUC) and Brier score were used to assess model performance.

RESULTS

A total of 2209 patients from the SEER database and 81 patients from our tertiary institution were included. All models had excellent calibration with AUC 0.84-0.85 and Brier score 0.15-0.16. After assessing the performance indicators according to the TRIPOD model, we found that the Elastic-Net Penalized Logistic Regression outperformed other models. The AUCs of the institutional data were 0.83 (imputed) and 0.85 (complete-case analysis) with a Brier score of 0.16.

CONCLUSION

Our study successfully developed five machine learning algorithms to assess 5-year survival in patients with LMS. The Elastic-Net Penalized Logistic Regression retained performance upon external validation with an AUC of 0.85 and Brier score of 0.15.

Randomized Phase 2 Clinical Trial of Olaratumab in Combination with Gemcitabine and Docetaxel in Advanced Soft Tissue Sarcomas

Gemcitabine plus docetaxel is an effective treatment regimen for advanced soft tissue sarcomas (STSs). However, the prognosis for patients remains poor, and thus there is an urgent medical need for novel and effective therapies to improve long-term outcomes. The aim of the ANNOUNCE 2 trial was to explore the addition of olaratumab (O) to gemcitabine (G) and docetaxel (D) for advanced STS. Adults with unresectable locally advanced/metastatic STS, ≤2 prior lines of systemic therapy, and ECOG PS 0-1 were eligible. In Phase 2, patients were randomized 1:1 from two cohorts (O-naïve and O-pretreated) to 21-day cycles of olaratumab (20 mg/kg Cycle 1 and 15 mg/kg other cycles, Days 1 and 8), gemcitabine (900 mg/m2, Days 1 and 8), and docetaxel (75 mg/m2, Day 8). The primary objective was overall survival (OS) in the O-naïve population (α level = 0.20). Secondary endpoints included OS (O-pretreated), other efficacy parameters, patient-reported outcomes, safety, pharmacokinetics, and immunogenicity. A total of 167 and 89 patients were enrolled in the O-naïve and O-pretreated cohorts, respectively. Baseline patient characteristics were well balanced. No statistically significant difference in OS was observed between the investigational vs. control arm for either cohort (O-naïve cohort: HR = 0.95 (95% CI: 0.64-1.40), p = 0.78, median OS, 16.8 vs. 18.0 months; O-pretreated cohort: HR = 0.67 (95% CI: 0.39-1.16), p = 0.15, median OS 19.8 vs. 17.3 months). Safety was manageable across treatment arms. There was no statistically significant difference in the primary endpoint of OS between the two arms in the O-naïve population, and therefore based on hierarchical evaluation no other outcomes in this study can be considered statistically significant. No new safety signals were observed.

Nomogram predicting overall survival after surgical resection for retroperitoneal leiomyosarcoma patients

Background

Surgery is the best way to cure the retroperitoneal leiomyosarcoma (RLMS), and there is currently no prediction model on RLMS after surgical resection. The objective of this study was to develop a nomogram to predict the overall survival (OS) of patients with RLMS after surgical resection.

Methods

Patients who underwent surgical resection from September 2010 to December 2020 were included. The nomogram was constructed based on the COX regression model, and the discrimination was assessed using the concordance index. The predicted OS and actual OS were evaluated with the assistance of calibration plots.

Results

118 patients were included. The median OS for all patients was 47.8 (95% confidence interval (CI), 35.9-59.7) months. Most tumor were completely resected (n=106, 89.8%). The proportions of French National Federation of Comprehensive Cancer Centres (FNCLCC) classification were equal as grade 1, grade 2, and grade 3 (31.4%, 30.5%, and 38.1%, respectively). The tumor diameter of 73.7% (n=85) patients was greater than 5 cm, the lesions of 23.7% (n=28) were multifocal, and 55.1% (n=65) patients had more than one organ resected. The OS nomogram was constructed based on the number of resected organs, tumor diameter, FNCLCC grade, and multifocal lesions. The concordance index of the nomogram was 0.779 (95% CI, 0.659-0.898), the predicted OS and actual OS were in good fitness in calibration curves.

Conclusion

The nomogram prediction model established in this study is helpful for postoperative consultation and the selection of patients for clinical trial enrollment.

The biology and treatment of leiomyosarcomas

Leiomyosarcoma (LMS) is a soft tissue sarcoma of smooth muscle origin that can arise in multiple anatomical sites and is broadly classified as extra-uterine LMS or uterine LMS. There is substantial interpatient heterogeneity within this histological subtype, and despite multi-modal therapy, clinical management remains challenging with poor patient prognosis and few new therapies available. Here we discuss the current treatment landscape of LMS in both the localised and advanced disease setting. We further describe the latest advances in our evolving understanding of the genetics and biology of this group of heterogeneous diseases and summarise the key studies delineating the mechanisms of acquired and intrinsic chemotherapy resistance in this histological subtype. We conclude by providing a perspective on how novel targeted agents such as PARP inhibitors may usher in a new paradigm of biomarker-driven therapies that will ultimately impact the outcomes of patients with LMS.

Metastasectomy in Leiomyosarcoma: A Systematic Review and Pooled Survival Analysis

Simple Summary

Leiomyosarcoma (LMS) is an aggressive soft tissue sarcoma with a poor prognosis. Approximately 40% of patients will develop metastatic disease. The optimal treatment for patients with metastatic LMS is not well established, and there are no randomized controlled trials regarding metastasectomy. This systematic review and pooled survival analysis aims to assess the survival in patients undergoing a metastasectomy for LMS and compare the outcomes based on the site of metastasectomy. We identified that patients with LMS metastases in the lungs, liver, spine, and brain can undergo metastasectomy with acceptable survival. Two studies have compared survival outcomes between patients treated and not treated with metastasectomy; despite their low quality, these studies support a survival benefit associated with metastasectomy.

Abstract

This study assesses the survival in patients undergoing metastasectomy for leiomyosarcoma (LMS) and compares the outcomes by the site of metastasectomy. We conducted a systematic review and pooled survival analysis of patients undergoing metastasectomy for LMS. Survival was compared between sites of metastasectomy. We identified 23 studies including 573 patients undergoing metastasectomy for LMS. The pooled median survival was 59.6 months (95% CI 33.3 to 66.0). The pooled median survival was longest for lung metastasectomy (72.8 months 95% CI 63.0 to 82.5), followed by liver (34.8 months 95% CI 22.3 to 47.2), spine (14.1 months 95% CI 8.6 to 19.7), and brain (14 months 95% CI 6.7 to 21.3). Two studies compared the survival outcomes between patients who did, versus who did not undergo metastasectomy; both demonstrated a significantly improved survival with metastasectomy. We conclude that surgery is currently being utilized for LMS metastases to the lung, liver, spine, and brain with acceptable survival. Although low quality, comparative studies support a survival benefit with metastasectomy. In the absence of randomized studies, it is impossible to determine whether the survival benefit associated with metastasectomy is due to careful patient selection rather than a surgical advantage; limited data were included about patient selection.

Late Diagnosis of Metastatic Leiomyosarcoma Originating in the Ureter

This case report highlights a patient with a leiomyosarcoma originating in the ureter. A chart review was performed on a single patient who presented with a malignant retroperitoneal mass measuring 11.5 × 8.2 × 6.5 cm with subsequent metastasis sites to the breast, pancreas, liver, and lungs. The diagnosis of a leiomyosarcoma is uncommon, accounting for 0.1-0.4% of all cancer diagnoses in the United States. The diagnosis of a leiomyosarcoma originating from the ureter is extremely rare with fewer than 20 reported cases to date. Lack of typical urinary tract cancer signs and symptoms prevented an early presentation, allowing for considerable tumor growth and making complete surgical resection unlikely. We present this case as an example of a rare presentation of a very rare disease and to emphasize the necessity for further research of leiomyosarcoma and early diagnosis.

Trabectedin and Radiation Therapy for Cardiac Metastasis From Leiomyosarcoma: A Case Report and Review of the Literature

Leiomyosarcoma (LMS) is one of the most frequent subtypes of soft-tissue sarcomas (STSs). Metastatic spread to the heart in cancer patients carries a poor prognosis and there is no known effective treatment. Cardiac metastases of STSs are very rare. Here we present the case of a 55-year-old patient who underwent surgical resection of a retroperitoneal leiomyosarcoma and then developed widespread metastatic disease, treated with a combination of local treatment and systemic therapy. Three years after surgical resection she presented with a cardiac intraventricular mass, which was treated with radiation therapy, while receiving systemic therapy with trabectedin. Such combination therapy was well-tolerated and effective, allowing a substantial dimensional reduction which is perduring to date, 18 months after diagnosis of cardiac metastasis. Available literature and data point to the feasibility and good tolerability of radiation therapy and trabectedin in metastatic sarcoma, yet this is the first report on the effectiveness of the combination for the treatment of cardiac disease. The extended survival since a metastatic relapse (more than 3 years) is likely the result of integrated systemic and loco-regional treatment, which should be always discussed within the framework of a multiprofessional and multidisciplinary setting.

Bone Metastases in Patients with Leiomyosarcoma: A Retrospective Analysis of Survival and Surgical Management

Background

Leiomyosarcomas (LMS) are malignancies with smooth muscle differentiation. Metastasis to the bone is not uncommon. The literature on the clinical course and management of such metastases is limited. Our study describes the clinical course of LMS to the bone, including survival rates, prognostic factors, and surgical management.

Methods

We retrospectively reviewed 396 LMS patients presenting at an academic center between 1995 and 2020. We included LMS patients diagnosed with bone metastases and excluded patients with primary LMS of bone. We evaluated survival time with the Kaplan-Meier survival method and used Cox's proportional hazards regression analysis to determine factors associated with survival.

Results

Forty-five patients with LMS (11%) had bone metastases. The most common LMS subtypes with bone metastases were uterine (N = 18, 40%) and retroperitoneal (N = 15, 33%). Bone metastasis was not an independent predictor of mortality by Cox regression analysis (HR 1.0, 95% CI: 0.67-1.5). Patients more frequently metastasized to the axial (N = 29, 64%) than to the appendicular (N = 5, 11%) skeleton. Bone was the first site of metastasis in 13 patients (29%). Patients presented with bone metastases at a median of 32.7 months (IQR: 5.2, 62.6) after initial LMS diagnosis. Twelve patients (27%) sustained a pathologic fracture. Twenty (44%) required surgical management, with 30 surgeries total. Three (15%) had a failure of reconstructive constructs. The median overall survival time was 69.7 months (IQR: 43.2, 124.5). There were no associations between the LMS subtype and survival. Pathologic fracture was an independent predictor of mortality by Cox regression analysis (HR 5.4, 95% CI: 1.8-16).

Conclusion

The majority of patients with metastatic LMS to bone survive greater than 5 years and frequently require surgical intervention. Extended survival in this patient population should inform fixation and implant choice. No anatomic subtype was associated with risk for bone metastases. Pathologic fracture was associated with worse survival.

Gastrointestinal leiomyosarcoma demonstrate a predilection for distant recurrence and poor response to systemic treatments

BACKGROUND

Primary leiomyosarcoma (LMS) of the gastrointestinal (GI) tract is rare. Limited literature exists regarding the clinical characteristics and outcome for patients with localised and metastatic disease.

METHODS

A retrospective chart review was performed for patients greater than 18 years of age diagnosed with GI LMS at The Royal Marsden Hospital between 1 January 2000-1 May 2020. Descriptive statistics were performed. Patients were censored at data cut-off date of 27 June 2020.

RESULTS

Forty-six patients with a median age at diagnosis of 54 years (range 25-85) were identified. Fifteen percent (n = 7) of patients previously received abdominal radiation for an unrelated cancer. All patients with localised disease (n = 36) had resection with oncological margins. For patients who underwent potentially curative surgery, median recurrence-free survival (mRFS) was 13 months (0.4-183 months), and half of these patients (n = 18) developed recurrent disease post resection (distant n = 16, local n = 2). Median overall survival (mOS) was 27 months for patients with distant recurrence. Twenty-one percent (n = 10) of patients presented with synchronous metastatic disease and their mOS was 19 months. Median progression-free survival (mPFS) for patients treated with conventional chemotherapy ranged from 2.0 to 8.0 months.

CONCLUSION

The risk of recurrence is significant, and recurrence-free survival was short even with complete oncologic resection. The relationship of prior abdominal radiotherapy to the development of GI LMS warrants further investigation. Outcomes with systemic therapy for metastatic disease were poor and there is a need for the development of more effective systemic therapies.

Clinical management and outcomes of primary ovarian leiomyosarcoma - Experience from a sarcoma specialist unit

Ovarian sarcomas account for 1% of all ovarian malignancies and amongst these, primary ovarian leiomyosarcoma is the rarest subtype. Primary ovarian leiomyosarcoma has a very poor prognosis, with less than 20% of patients being alive at 5 years. Only a few cases have been published in the literature and there is very limited knowledge on the clinical behaviour and optimal management of these tumours. We have performed a retrospective analysis of a prospectively maintained database to identify all primary ovarian leiomyosarcoma diagnosed and treated at the Royal Marsden NHS Foundation Trust between 1998 and 2020. Sixteen patients were identified from our database and fifteen were eligible for the analysis. Twelve patients presented with localized disease and underwent initial surgery and three patients had metastatic disease at presentation. Recurrence-free survival post-surgery was 16 months. Eight patients received first-line chemotherapy and four patients received second-line chemotherapy. Two patients had indolent metastatic disease and benefited from local therapies only. The median overall survival in the metastatic setting in our cohort was 51 months, which is consistent with previously published cases. Primary ovarian leiomyosarcoma is an extremely rare malignancy with a poor prognosis. This study is the largest case series of primary ovarian leiomyosarcoma published to date, providing clinically important information regarding survival and metastatic rate as well as treatment outcomes in the metastatic setting.

Comparison of clinicopathological features and outcomes in patients with primary leiomyosarcoma of bone and soft tissue

BACKGROUNDS AND OBJECTIVES

This investigation sought to describe the outcomes of primary leiomyosarcoma of bone (PLB) compared to soft tissue leiomyosarcoma (SLMS).

METHODS

This was a review of the Surveillance, Epidemiology, and End Results database from 1975 to 2016. Kaplan-Meier methods were used to estimate disease-specific survival (DSS), and a Cox regression model was used to identify prognostic factors.

RESULTS

Of the 7502 identifiable cases, 1% (n = 74) were PLB and 99% (n = 7428) were SLMS. Survival was the same between PLB and SLMS (p = .209). On multivariable analysis for high-grade SLMS, radiation (neoadjuvant: hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.4-0.8; p = .003; adjuvant: HR, 0.75; 95% CI, 0.6-0.9; p = .008) and surgery (procedure specific) improved DSS. For PLB, wide resection/limb salvage (HR, 0.40; 95% CI, 0.3-0.5; p = .018) and amputation (HR, 0.69; 95% CI, 0.5-0.9; p < .001) were positive prognostic factors. Neither radiation nor chemotherapy were prognostic factors for survival in PLB.

CONCLUSIONS

For SLMS, radiation portends a survival advantage. For PLB, however, neither chemotherapy nor radiation were significant prognostic factors, which suggests the optimal treatment for PLB, similar to other primary soft tissue sarcomas originating in bone, remains an unmet medical need.

Epstein-Barr virus negative smooth muscle neoplasm of the stomach in a young woman

Gastric smooth muscle neoplasms are rare and poorly investigated malignancies. Their importance relies on differential diagnosis with more frequent neoplasms(e.g. GIST), on their often mild and deceitful clinical presentation and on their heterogeneous outcome. Moreover, the pathogenesis of gastric leiomyosarcoma seems to point to some acknowledged oncogenic factors such as radiations or oncogenic viral infections. Herein, we describe a case of metastatic gastric leiomyosarcoma in a young woman, previously diagnosed with acute lymphoblastic leukemia treated with chemoradiotherapy.

A case of laparoscopic resection of leiomyosarcoma arising in the mesentery of descending colon: a case report and review of the literature

Leiomyosarcoma of mesenteric origin is rare and may be managed by laparoscopic surgery as a less invasive procedure, on the condition that the tumor can be resected with a safe margin.

Inhibition of AKT-Signaling Sensitizes Soft Tissue Sarcomas (STS) and Gastrointestinal Stromal Tumors (GIST) to Doxorubicin via Targeting of Homology-Mediated DNA Repair

Activation of the phosphoinositide 3-kinase (PI3K)/Akt/mTOR pathway is well documented for a broad spectrum of human malignancies supporting their growth and progression. Accumulating evidence has also implicated AKT as a potent modulator of anti-cancer therapies via regulation of DNA damage response and repair (DDR) induced by certain chemotherapeutic agents and ionizing radiation (IR). In the present study, we examined the role of AKT signaling in regulating of Rad51 turnover and cytotoxic effects of topoisomerase II inhibitor, doxorubicin (Dox) in soft tissue sarcomas (STS) and gastrointestinal stromal tumors (GIST) in vitro. Blocking of AKT signaling (MK-2206) enhanced cytotoxic and pro-apoptotic effects of Dox in vast majority of STS and GIST cell lines. The phosphorylated form of Akt co-immunoprecipitates with Rad51 after Dox-induced DNA damage, whereas Akt inhibition interrupts this interaction and decreases Rad51 protein level by enhancing protein instability via proteasome-dependent degradation. Inhibition of Akt signaling in Dox-treated cells was associated with the increased number of γ-H2AX-positive cells, decrease of Rad51 foci formation and its colocalization with γ-H2AX foci, thereby revealing unsuccessful DDR events. This was also in consistency with an increase of tail moment (TM) and olive tail moment (OTM) in Dox-treated GIST and STS cells cultured in presence of Akt inhibitor after Dox washout. Altogether, our data illustrates that inhibition of AKT signaling is STS and GIST might potentiate the cytotoxic effect of topoisomerase II inhibitors via attenuating the homology-mediated DNA repair.

Pleomorphic Leiomyosarcoma of the Adrenal Gland in a Young Woman: A Case Report and Review of the Literature

Leiomyosarcoma usually arises in the uterus, abdominal and urologic viscera, and walls of large and small blood vessels. However, primary adrenal leiomyosarcoma is extremely rare with only 39 cases previously reported in English-language literature. We report a case of a 29-year-old previously healthy woman with an incidentally found right adrenal-occupying lesion. CT scan revealed a right adrenal mass measuring 3.3×3.4 cm in size. The tumor was successfully removed by laparoscopic adrenalectomy. Postoperative histopathologic examination showed spindle cells arranged in interlacing fascicles with pleomorphism and a high mitotic rate. An immunohistochemical examination showed positive staining for SMA, desmin, vimentin and H-caldesmon, and the diagnosis of a well-differentiated adrenal leiomyosarcoma was established. The patient received no other oncological treatment after surgery and currently has no evidence of residual disease or tumor recurrence according to imaging follow-up.

Conjunctival Leiomyosarcoma, a Rare Neoplasm Always Originating at the Limbus? Report of a New Case and Review of 11 Published Cases

PURPOSE OF THE STUDY

To describe the differential diagnosis and management of a rare conjunctival malignancy.

PROCEDURES

A 79-year-old man presented with a conjunctival mass at the limbus. Excisional biopsy revealed a malignant mesenchymal tumor with myogenic differentiation. Six months later, three suspect lesions developed at the border of the previous excision. Pathological diagnosis pointed to a leiomyosarcoma. Adjuvant radiotherapy with strontium-90 brachytherapy was applied. After 3 years, there was neither recurrence nor distant metastases. A literature review revealed 11 cases of conjunctival leiomyosarcoma.

RESULTS

All 12 cases seemed to originate at the limbal conjunctiva. Scleral invasion was found only in one patient with multiple previous resections. Corneal invasion was reported in two patients. Four patients had a globe-sparing resection. In two of them, margins were not tumor free and additional brachytherapy gave a tumor-free follow-up of 1 and 3 years. Four cases underwent an exenteration.

CONCLUSION AND MESSAGE

Primary conjunctival leiomyosarcoma is a rare tumor with a favorable prognosis due to early detection and consequently limited size. Diagnosis involves histopathological investigation including immunohistochemistry. If possible, complete resection has the best prognosis. Adjunctive radiotherapy can be effective when the margins are not free and should be considered.

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.

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.

Development and Validation of a Prognostic Nomogram for Extremity Soft Tissue Leiomyosarcoma

Background: Extremity soft tissue leiomyosarcoma (LMS) is a rare disease with a poor prognosis. The aim of this study is to develop nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) of patients with extremity soft tissue LMS.

Methods: Based on the Surveillance, Epidemiology, and End Results (SEER) database, 1,528 cases of extremity soft tissue LMS diagnosed between 1983 and 2015 were included. Cox proportional hazards regression modeling was used to analyze prognosis and obtain independent predictors. The independent predictors were integrated to develop nomograms predicting 5- and 10-year OS and CSS. Nomogram performance was evaluated by a concordance index (C-index) and calibration plots using R software version 3.5.0.

Results: Multivariate analysis revealed that age ≥60 years, high tumor grade, distant metastasis, tumor size ≥5 cm, and lack of surgery were significantly associated with decreased OS and CSS. These five predictors were used to construct nomograms for predicting 5- and 10-year OS and CSS. Internal and external calibration plots for the probability of 5- and 10-year OS and CSS showed excellent agreement between nomogram prediction and observed outcomes. The C-index values for internal validation of OS and CSS prediction were 0.776 (95% CI 0.752–0.801) and 0.835 (95% CI 0.810–0.860), respectively, whereas those for external validation were 0.748 (95% CI 0.721–0.775) and 0.814 (95% CI 0.785–0.843), respectively.

Conclusions: The proposed nomogram is a reliable and robust tool for accurate prognostic prediction in patients with extremity soft tissue LMS.

BRCA1/2 Functional Loss Defines a Targetable Subset in Leiomyosarcoma

BACKGROUND

Soft-tissue sarcomas (STS) describe a heterogeneous group of mesenchymal tumors with limited treatment options. Targeted therapies exist for BRCA1/2 gene alterations, but their prevalence and role have not been fully described in STS. Here, we present the largest effort to characterize the frequency of homologous recombination (HR) DNA repair pathway alterations in STS subtypes and highlight the unique nature of leiomyosarcoma (LMS).

MATERIALS AND METHODS

DNA sequencing data were analyzed for HR pathway alterations for 1,236 patients with STS. DNA sequencing data from an additional 1,312 patients were used to confirm the prevalence of HR pathway alterations in LMS. Four uterine LMS (uLMS) patients with functional BRCA2 loss were evaluated for response to poly (ADP-ribose) polymerase (PARP) inhibition.

RESULTS

In an unselected STS study population, BRCA2 alterations were identified in 15 (1%) patients, and homozygous BRCA2 loss was detected in 9 (<1%). However, subset analysis revealed that these BRCA2 alterations were concentrated in uLMS as compared with any other STS subtype. Notably, 10% of uLMS tumors had a BRCA2 alteration. We further report that PARP inhibitors had demonstrated durable clinical benefit in four uLMS patients with BRCA2 loss.

CONCLUSION

HR pathway alterations are rare in most STS. However, we identify uLMS to be enriched for BRCA2 loss and report the positive outcomes of a series of patients treated with PARP inhibitors. Our data suggest that patients with uLMS should be considered for somatic BRCA2 profiling. Prospective trials are necessary to confirm the efficacy of PARP inhibition in uLMS.

IMPLICATIONS FOR PRACTICE

Soft-tissue sarcomas are a highly morbid, diverse set of tumors with limited treatment options. This study identifies an increased prevalence of functional BRCA1/2 loss in patients with uterine leiomyosarcoma (uLMS). It also presents four patients with uLMS and BRCA2 loss who achieved durable clinical benefit from poly (ADP-ribose) polymerase inhibition. These data suggest that patients with uLMS in particular should be screened for BRCA1/2 alterations and may benefit from treatment targeted to these alterations.

Retroperitoneal Leiomyosarcoma From the Radiologic Pathology Archives

Leiomyosarcoma is a malignant neoplasm that shows smooth muscle differentiation. It is the second most common sarcoma to affect the retroperitoneum. Retroperitoneal leiomyosarcomas may grow to large sizes before detection and may be an incidental finding at imaging. When symptomatic, retroperitoneal leiomyosarcoma may cause compressive symptoms, including pain. Retroperitoneal leiomyosarcoma most commonly manifests as a large soft-tissue mass, with areas of necrosis. The most frequent pattern of growth is an entirely extravascular mass. Less commonly, leiomyosarcoma may demonstrate both extravascular and intravascular components. Rarely, retroperitoneal leiomyosarcomas are completely intravascular, typically arising from the inferior vena cava. Given its variable imaging features, a large variety of neoplastic and nonneoplastic conditions are included in the differential diagnosis of retroperitoneal leiomyosarcoma. In this review, the authors discuss retroperitoneal leiomyosarcoma, with emphasis on the pathologic basis of disease, and illustrate the multimodality imaging appearances of retroperitoneal leiomyosarcoma using cases from the Radiologic Pathology Archives of the American Institute for Radiologic Pathology. The authors review important differential considerations of retroperitoneal leiomyosarcoma, focusing on the extravascular pattern of growth, and emphasize clinical and imaging features that help radiologists differentiate leiomyosarcoma from the most frequent mimics. The information presented in this review will aid radiologists in fulfilling their key roles in the diagnosis, operative planning, and follow-up of patients with retroperitoneal leiomyosarcoma.

Leiomyosarcoma of the stomach with metastasis to the liver: a case report with review of the literature

Leiomyosarcoma of the stomach is a very rare malignancy that was not distinguished from the more frequent gastrointestinal stromal tumors until early 2000s. Here we report on a case of a metastatic disease that developed in a 47-year-old man 2 years after he was diagnosed with the primary tumor and treated with curative surgical excision and adjuvant doxorubicin. The primary and metastatic lesions were positive for smooth muscle markers α-smooth muscle actin and h-caldesmon and negative for CD117, DOG-1 and S100 by immunohistochemistry. Metastatic disease progressed on additional monotherapy with doxorubicin and docetaxel-gemcitabine combination, and stable disease was achieved upon treatment with pazopanib. Patient is surviving 35 months since diagnosis of the primary tumor and 11 months since diagnosis of metastatic disease.

Primary leiomyosarcoma of the bone: a case report and a review of the literature

RATIONALE

Leiomyosarcoma (LMS) is a malignant sarcoma that can occur in different anatomic sites, including the bone, showing similar histological characteristics but heterogeneous clinical behavior and prognosis. Primary bone LMS was first described in 1965. It is a very rare sarcoma, accounting for <0.7% of all primary malignant bone tumors.

PATIENT CONCERNS

We report the case of a 52-year-old male with primary bone LMS who presented with a solitary osteolytic lesion with focal cortical destruction in the left clavicle, seen on an x-ray and subsequent computed tomography (CT) scan.

DIAGNOSIS

The multidisciplinary Osteoncology team of our institute planned a biopsy that revealed the presence of spindle and pleomorphic cells with a positive reaction for smooth muscle actin and desmin at immunohistochemical analysis, without the presence of cartilage or bone matrix. These results were consistent with a high-grade malignant LMS arising from the bone.

INTERVENTIONS

Complete surgical resection of the tumor was performed and a decision was made with the patient not to proceed with adjuvant chemotherapy or radiotherapy.

OUTCOMES

After more than 1 year of surgery, the patient is well, with no evidence of recurrent or metastatic disease. Follow-up is ongoing.

LESSONS

Little is known about the biology and clinical behavior of bone LMS due to its extreme rarity. A multidisciplinary team in a specialized center is needed for the optimal management of the disease. Surgery with a curative intent is the cornerstone of treatment of localized disease. No data are available about chemotherapy in neoadjuvant, adjuvant, or advanced settings. Further research is needed to identify more effective therapies.

Update on the role of trabectedin in the treatment of intractable soft tissue sarcomas

Soft tissue sarcomas (STS) represent a variety of tumors of mesenchymal origin, accounting for about 1% of all adult cancers. This group of tumors comprises over 60 different histotypes with different biology showing different sensitivity to therapeutic agents. For decades, the standard first-line systemic treatment of metastatic STS has comprised anthracycline based-chemotherapy. Second-line therapy options include agents such as ifosfamide, gemcitabine, and pazopanib, but the optimal sequential therapy for the management of metastatic disease has yet to be defined. Trabectedin is one of the new molecules approved for patients in progression after first-line chemotherapy with anthracyclines or for those unfit for these agents. The compound is characterized by multiple potential mechanisms of action combining cytotoxic, targeted, and immunological effects. This article takes an in-depth look at the role of trabectedin in the management of metastatic STS, including L-sarcoma and non-L-sarcoma.

The Imaging and Pathological Features of Metastatic Leiomyosarcoma in the Gallbladder

Uterine leiomyosarcoma is a rare and aggressive malignancy with poor overall prognosis. There have been few reports of metastatic leiomyosarcoma in the gallbladder. We report a case of a 41-year-old female who underwent total abdominal hysterectomy due to presumed uterine fibroids. The postoperative pathology revealed high-grade pleomorphic leiomyosarcoma, with involvement of the uterine serosal surface. She subsequently underwent exploratory laparotomy, followed by pelvic radiation and chemotherapy. Since initial management she has developed metastatic disease and has been under treatment and surveillance for 11 years. She has undergone multiple surgical procedures and numerous lines of systemic therapy for metastatic leiomyosarcoma, including cholecystectomy for a metastatic lesion in the gallbladder. There have been no previous reports of metastatic leiomyosarcoma in the gallbladder. Despite extensive metastatic disease this patient has had prolonged survival with multi-modality management.

Survival of patients with metastatic leiomyosarcoma: the MD Anderson Clinical Center for targeted therapy experience

Advanced stage leiomyosarcoma (LMS) is incurable with current systemic antitumor therapies. Therefore, there is clinical interest in exploring novel therapeutic regimens to treat LMS. We reviewed the medical records of 75 consecutive patients with histologically confirmed metastatic LMS, who had been referred to the Clinical Center for Targeted Therapy at MD Anderson Cancer Center. To lay the foundation for potential phase I trials for the treatment of advanced LMS, we analyzed tumor response and survival outcome data. The frequent hotspot gene aberrations that we observed were the TP53 mutation (65%) and RB1 loss/mutation (45%) detected by Sequenom or next-generation sequencing. Among patients treated with gene aberration-related phase I trial therapy, the median progression-free survival was 5.8 months and the median overall survival was 15.9 months, significantly better than in patients without therapy (1.9 months, P = 0.001; and 8.7 months, P = 0.013, respectively). Independent risk factors that predicted shorter overall survival included hemoglobin <10 g/dL, body mass index <30 kg/m2 , serum albumin <3.5 g/dL, and neutrophil above upper limit of normal. The median survivals were 19.9, 7.6, and 0.9 months for patients with 0, 1 or 2, and ≥3 of the above risk factors, respectively (P < 0.001). A prognostic scoring system that included four independent risk factors might predict survival in patients with metastatic LMS who were treated in a phase I trial. Gene aberration-related therapies led to significantly better clinical benefits, supporting that further exploration with novel mechanism-driven therapeutic regimens is warranted.

Primary thyroid leiomyosarcoma: A case report and literature review

Primary thyroid leiomyosarcoma (LMS) is an extremely rare soft tissue cancer; only 22 cases have been reported in the literature to date. In the current study, the case of an 83-year-old male patient who presented with a neck mass that had grown rapidly over the previous 3 months is reported. The patient underwent thyroid lobectomy twice and two cycles of immunotherapy for the treatment of primary thyroid LMS; however, he succumbed to the disease 5 months after the second surgery. An accurate diagnosis of primary thyroid LMS is difficult, as the disease is often misdiagnosed as anaplastic carcinoma, and requires the combined assessment of clinical, imaging and pathological data. Diagnosis of the current patient with primary thyroid LMS and a comprehensive review of the relevant literature are presented herein.

PI3K/AKT/mTOR inhibition in combination with doxorubicin is an effective therapy for leiomyosarcoma

BACKGROUND

Leiomyosarcoma (LMS) is a common type of soft tissue sarcoma that responds poorly to standard chemotherapy. Thus the goal of this study was to identify novel selective therapies that may be effective in leiomyosarcoma by screening cell lines with a small molecule library comprised of 480 kinase inhibitors to functionally determine which signalling pathways may be critical for LMS growth.

METHODS

LMS cell lines were screened with the OICR kinase library and a cell viability assay was used to identify potentially effective compounds. The top 10 % of hits underwent secondary validation to determine their EC50 and immunoblots were performed to confirm selective drug action. The efficacy of combination drug therapy with doxorubicin (Dox) in vitro was analyzed using the Calcusyn program after treatment with one of three dosing schedules: concurrent treatment, initial treatment with a selective compound followed by Dox, or initial treatment with Dox followed by the selective compound. Single and combination drug therapy were then validated in vivo using LMS xenografts.

RESULTS

Compounds that targeted PI3K/AKT/mTOR pathways (52 %) were most effective. EC50s were determined to validate these initial hits, and of the 11 confirmed hits, 10 targeted PI3K and/or mTOR pathways with EC50 values <1 μM. We therefore examined if BEZ235 and BKM120, two selective compounds in these pathways, would inhibit leiomyosarcoma growth in vitro. Immunoblots confirmed on-target effects of these compounds in the PI3K and/or mTOR pathways. We next investigated if there was synergy with these agents and first line chemotherapy doxorubicin (Dox), which would allow for earlier introduction into patient care. Only combined treatment of BEZ235 and Dox was synergistic in vitro. To validate these findings in pre-clinical models, leiomyosarcoma xenografts were treated with single agent and combination therapy. BEZ235 treated xenografts (n = 8) demonstrated a decrease in tumor volume of 42 % whereas combining BEZ235 with Dox (n = 8) decreased tumor volume 68 % compared to vehicle alone.

CONCLUSIONS

In summary, this study supports further investigation into the use of PI3K and mTOR inhibitors alone and in combination with standard treatment in leiomyosarcoma patients.

Metastatic mesenteric dedifferentiated leiomyosarcoma: a case report and a review of literature

Background

Abdominal leiomyosarcoma arising from the mesentery is a rare malignancy. It is an aggressive entity with an overall 5 year survival rate between 20 and 30 %. Surgical resection is the cornerstone of primary treatment and may be curative for localized disease. However, patients often develop intra-abdominal relapse and/or metastatic disease. If surgical resection is not feasible, palliative chemotherapy is the treatment of choice. However, there are no clear guidelines regarding chemotherapy; neither in the adjuvant nor advanced setting.

Case presentation

We present a 40 year-old woman, with a mesenteric leiomyosarcoma, who underwent radical tumor resection and did not receive adjuvant oncological therapy. Three months postoperatively, she developed metastatic disease to the lungs and liver. After multidisciplinary assessment she received an unconventional histological-subtype-tailored chemotherapy comprising 3–4 regimens. Initially, there was a decrease both in number and size of metastases. Ultimately, an almost complete radiological response was seen. Subsequent surgical resection and radiofrequency ablation of residual metastatic foci in the liver and lung brought her into complete clinical remission. She is presently tumor free, 36 months following diagnosis of metastatic disease.

Conclusions

To our knowledge, this is the first report of a patient with metastatic mesenteric leiomyosarcoma who is in complete clinical and radiological long-term remission following very aggressive multimodal treatment; including intense poly-drug chemotherapy and without any demonstrable long-term side effects. Given the rarity of mesenteric leiomyosarcoma and lack of guidelines regarding oncological therapy, we suggest that multimodal therapy including aggressive chemotherapy, guided by a multidisciplinary team, is essential to achieve an optimal outcome.

Regulated lysosomal exocytosis mediates cancer progression

Understanding how tumor cells transition to an invasive and drug-resistant phenotype is central to cancer biology, but the mechanisms underlying this transition remain unclear. We show that sarcomas gain these malignant traits by inducing lysosomal exocytosis, a ubiquitous physiological process. During lysosomal exocytosis, the movement of exocytic lysosomes along the cytoskeleton and their docking at the plasma membrane involve LAMP1, a sialylated membrane glycoprotein and target of the sialidase NEU1. Cleavage of LAMP1 sialic acids by NEU1 limits the extent of lysosomal exocytosis. We found that by down-regulation of NEU1 and accumulation of oversialylated LAMP1, tumor cells exacerbate lysosomal exocytosis of soluble hydrolases and exosomes. This facilitates matrix invasion and propagation of invasive signals, and purging of lysosomotropic chemotherapeutics. In Arf (-⁄-) mice, Neu1 haploinsufficiency fostered the development of invasive, pleomorphic sarcomas, expressing epithelial and mesenchymal markers, and lysosomal exocytosis effectors, LAMP1 and Myosin-11. These features are analogous to those of metastatic, pleomorphic human sarcomas, where low NEU1 levels correlate with high expression of lysosomal exocytosis markers. In a therapeutic proof of principle, we demonstrate that inhibiting lysosomal exocytosis reversed invasiveness and chemoresistance in aggressive sarcoma cells. Thus, we reveal that this unconventional, lysosome-regulated pathway plays a primary role in tumor progression and chemoresistance.