Malignant Soft-Tissue Sarcomas

Molecular Imaging in Soft-tissue Sarcoma: Evolving Role of FDG PET

Soft tissue sarcomas are a rare and heterogenous group of tumors that account for 2% of all cancer-related deaths. Molecular imaging with FDG PET can offer valuable metabolic information to help inform clinical management of soft tissue sarcomas that is unique and complementary to conventional diagnostic imaging techniques. FDG PET imaging often correlates with tumor grade, can help guide biopsy, and frequently detects additional sites of disease compared to conventional imaging in patients being considered for definitive or salvage therapy. Traditional size-based evaluation of treatment response is often inadequate in soft tissue sarcoma and changes in metabolic activity can add significant value to interim and end of treatment imaging for high-grade sarcomas. FDG PET can be used for detection of recurrence or malignant transformation and thus play a vital role in surveillance. This article reviews the evolving role of FDG PET in initial diagnosis, staging, treatment response assessment, and restaging. Further studies on the use of FDG PET in soft sarcoma are needed, particularly for rare histopathologic subtypes.

Axitinib in patients with advanced/metastatic soft tissue sarcoma (Axi-STS): an open-label, multicentre, phase II trial in four histological strata

BACKGROUND

Axitinib is an oral vascular endothelial growth factor receptor inhibitor with anti-tumour activity in renal, thyroid, and pancreatic cancer.

METHODS

Axi-STS was a pathologically-stratified, non-randomised, open-label, multi-centre, phase II trial of continuous axitinib treatment in patients ≥16 years, performance status ≤2, with pathologically-confirmed advanced/metastatic soft tissue sarcoma (STS). Patients were recruited within four tumour strata, each analysed separately: angiosarcoma, leiomyosarcoma, synovial sarcoma, or other eligible STSs. The primary outcome was progression-free survival at 12 weeks (PFS12). A Simon's two-stage design with activity defined as PFS12 rate of 40% determined a sample size of 33 patients per strata.

RESULTS

Between 31-August-2010 and 29-January-2016, 145 patients were recruited: 38 angiosarcoma, 37 leiomyosarcoma, 36 synovial sarcoma, and 34 other subtypes. PFS12 rate for each stratum analysed was 42% (95% lower confidence interval (LCI); 29), 45% (95% LCI; 32), 57% (95% LCI; 42), and 33% (95% LCI; 21), respectively. There were 74 serious adverse events including two treatment-related deaths of pulmonary haemorrhage and gastrointestinal bleeding. Fatigue and hypertension were the most common grade 3 adverse events.

CONCLUSIONS

Axitinib showed clinical activity in all STS strata investigated. The adverse event profile was acceptable, supporting further investigation in phase III trials.

CLINICAL TRIAL REGISTRATION

ISRCTN 60791336.

Identification and validation of a nomogram predicting cancer-specific survival for elderly patients with adult fibrosarcoma: a multicenter retrospective study

Background

Due to the low incidence of adult fibrosarcoma (AFS), it is difficult for clinicians to assess cancer-specific survival (CSS) in elderly patients based on this study. The study aimed to develop nomograms capable of accurately predicting 3-, 5-, and 8-year CSS in patients over 40 years of age with AFS.

Methods

Data were collected from The Surveillance, Epidemiology, and End Results (SEER) registry. 586 patients were included in this study. Univariate as well as multivariate Cox regression analyses were applied to identify independent risk factors. A nomogram was constructed and validated to predict the 3-, 5-, and 8-year CSS of patients.

Results

Five variables including age, sex, stage, grade, and chemotherapy status were considered independent risk factors and were used to construct the nomogram. The nomogram was well validated. The C-indexes of the training cohort and the validation cohort are 0.766 and 0.780, respectively. In addition, the area under the curves for 3-, 5- and 8-year CSS are 0.824, 0.846 and 0.840 in the training cohort, 0.835, 0.806 and 0.829 in the validation cohort. Calibration curves were also plotted to show that predicted endings have a well fit for the true endings. Finally, decision curve analysis demonstrates that the nomogram can bring a high benefit to patients.

Conclusion

We successfully constructed a highly accurate nomogram to predict the CSS of AFS patients at 3-, 5-, and 8 years. The nomogram can greatly help clinicians and patients with AFS.

Mesenchymal loss of p53 alters stem cell capacity and models human soft tissue sarcoma traits

Soft tissue sarcomas (STSs) are a heterogeneous group of tumors that originate from mesenchymal cells. p53 is frequently mutated in human STS. In this study, we found that the loss of p53 in mesenchymal stem cells (MSCs) mainly causes adult undifferentiated soft tissue sarcoma (USTS). MSCs lacking p53 show changes in stem cell properties, including differentiation, cell cycle progression, and metabolism. The transcriptomic changes and genetic mutations in murine p53-deficient USTS mimic those seen in human STS. Furthermore, single-cell RNA sequencing revealed that MSCs undergo transcriptomic alterations with aging-a risk factor for certain types of USTS-and that p53 signaling decreases simultaneously. Moreover, we found that human STS can be transcriptomically classified into six clusters with different prognoses, different from the current histopathological classification. This study paves the way for understanding MSC-mediated tumorigenesis and provides an efficient mouse model for sarcoma studies.

Association between microRNA 671 polymorphisms and the susceptibility to soft tissue sarcomas in a Chinese population

This study evaluated the association between the microRNA (miRNA) gene polymorphisms and the susceptibility to soft tissue sarcomas (STSs). In this case–control study, DNA was extracted from leukocytes in peripheral blood, which was collected from 169 STSs patients and 170 healthy controls. Three SNPs for miR-210, five SNPs for miR-206, two SNPs for miR-485, two SNPs for miR-34b, two SNPs for miR-671, and three SNPs for miR-381 were investigated and genotyped using a Sequenom Mass ARRAY matrix-assisted laser desorption/ionization-time of flight mass spectrometry platform. Unconditional logistic regression analysis was used to analyze the association between miRNA gene polymorphisms and the susceptibility to STSs. The results showed that miR-671 rs1870238 GC + CC (OR = 1.963, 95% CI = 1.258–3.064, P = 0.003) and miR-671 rs2446065 CG + GG (OR =1.838, 95% CI = 1.178–2.868, P = 0.007) may be genetic risk factors for STSs after adjustment for age and smoking. Therefore, this study suggests that individuals carrying the GC + CC genotype for miR-671 rs1870238 or the CG + GG genotype for miR-671 rs2446065 are susceptible to STSs.

Long-Term Efficacy and Safety of Anlotinib as a Monotherapy and Combined Therapy for Advanced Sarcoma

Objective

To analyze the effectiveness of the long-term (> 12 months) administration of anlotinib as a monotherapy or combined therapy in patients with advanced sarcomas.

Methods

A retrospective analysis was conducted of patients with advanced sarcomas with measurable target lesions since 2018. Twenty-two of the patients had taken anlotinib regularly for > 12 months. The patients’ general information and the drug’s clinical efficacy and toxicity data were collected and statistically analyzed using RECIST 1.1 to measure the target lesions and tumor PFS time as the main endpoints. We used a swimmer plot to observe the drug’s efficacy and duration, and employed a waterfall plot to express the best treatment effect.

Results

The study included 14 male and 8 female patients, ranging in age from 14 to 75 (mean: 44.82) years. The primary diseases included alveolar soft part sarcoma, synovial sarcoma, leiomyosarcoma, and others. The metastasis sites were the lungs in fifteen cases, lymph nodes in four cases, and multiple sites in three cases. Fourteen patients had previously undergone chemotherapy. The current therapy protocol was oral anlotinib alone for nine cases, combination chemotherapy for nine cases, and combination immunotherapy (anti-PD-1) for four cases. The highest clinical efficacy was complete remission (CR) in four (18.18%) cases, partial response (PR) in five (22.73%) cases, and stable disease in 13 (59.09%) cases, with an odds ratio of response of 40.91%. The mean PFS for the CR, PR, and stable disease groups was 16.50, 14.50, and 29.31 months, respectively (p < 0.05). The main adverse effects included hand-foot syndrome, hypertension, and leukopenia.

Conclusion

Anlotinib monotherapy or combination therapy can be more effective and safer for certain advanced sarcomas, with more extended maintenance and acceptable side effects. Clinical efficacy at the CR and PR levels might predict the long-term PFS in certain advanced sarcomas.

Adult Soft-Tissue Sarcomas of the Extremities

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Soft-tissue sarcomas (STS) in adults comprise a heterogeneous group of tumors of mesenchymal origin that share similar biological patterns of local tumor growth and metastatic dissemination.

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The judicious use of imaging studies, biopsy techniques, and pathological evaluations is essential for accurate diagnosis and for planning treatment strategy.

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Wide local resection and radiation therapy form the cornerstone of management of high-grade STS. The role of adjuvant radiation therapy is questionable in the management of small (≤5 cm) superficial lesions that can be resected with negative margins. Chemotherapy given to patients who have nonmetastatic, high-grade STS results in varying benefit in terms of local tumor control and overall survival.

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Coordinated care by a multidisciplinary team of trained surgeons, medical oncologists, radiologists, radiation oncologists, and pathologists has been documented to improve local tumor control and the overall survival of patients with STS.

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Although considerable progress in tumor diagnostics and targeted therapies has been made over the past 2 decades, recommendations and controversies relating to tumor imaging and margins of resection have not changed.

Lymphatic Complications Prevention and Soft Tissue Reconstruction after Soft Tissue Sarcoma Resection in the Limbs

Background and Objectives: The definitive treatment of soft tissue sarcomas (STS) requires a radical surgical removal of the tumor, which often leads to large soft tissue defects. When they are located in the limbs, significant damage to the lymphatic pathways is not uncommon. In the present article, we present different techniques aimed at both reconstructing the defect and restoring sufficient lymph drainage, thus preventing short- and long-term lymphatic complications. Materials and Methods: Between 2018 and 2020, 10 patients presenting a soft tissue defect with lymphatic impairment received a locoregional reconstruction by means of either pedicled or free SCIP flap. Seven patients required a second flap to reach a good dead space obliteration. In six cases, we performed an interpositional flap, namely a soft tissue transfer with lymphatic tissue preservation, and in four cases a lymphatic flow-through flap. In all cases, the cause of the defect was STS surgical excision. The average age was 60.5 years old (ranging 39-84), seven patients were females and six were males. Results: All the patients were successfully treated. In two cases, minor post-operative complications were encountered (infected seroma), which were conservatively managed. No secondary procedures were required. The average follow-up was 8.9 months (ranging 7-12 months). No signs of lymphedema were reported during this time. In all cases, complete range of motion (ROM) and a good cosmetic result were achieved. Conclusions: A reconstructive procedure that aims not only to restore the missing volume, but also the lymphatic drainage might successfully reduce the rate of postoperative complications. Both lymphatic interpositional flaps and lymphatic flow-through flaps could be effective, and the right choice must be done according to each patient's needs.

Antitumor and immunoregulatory activities of a novel polysaccharide from Astragalus membranaceus on S180 tumor-bearing mice

The Astragalus membranaceus polysaccharide (APS4) with direct cytotoxicity on various cancer cells has been prepared in our previous study, while the underlying therapeutic role of APS4 on solid tumors in vivo hasn't been investigated yet. Therefore, in this paper, the lymphocytes-mediated antitumor and immunoregulatory activities of APS4 were researched by establishing S180 tumor-bearing mice model. Flow cytometry analysis revealed that APS4 could effectively regulate the percentages of CD3⁺, CD4⁺, CD8⁺ T cells and CD19⁺ B cells in thymus, peripheral blood and spleen of S180 tumor-bearing mice, dose-dependently. H&E staining and cell cycle determination of solid tumors manifested that APS4 treatment could significantly inhibit the growth of solid tumors by inducing cells apoptosis. Furthermore, two-dimensional electrophoresis and western blot analysis further demonstrated that APS4 could activate antitumor-related immune cells and promote anaerobic metabolism of tumor microenvironment, thereby causing the apoptosis of S180 tumor cells. These data implicated that APS4 could be used as a potential dietary supplement for immune enhancement.

Heterogeneity of Soft Tissue Sarcomas and Its Implications in Targeted Therapy

Soft tissue sarcomas are a set of malignancies of mesenchymal origin. Due to the rarity and similarity in clinical presentation, they are grouped together and treated similarly in clinic. The response rates for current chemotherapy are around 20% and the median overall survival for advanced soft tissue sarcoma are less than 2 years. Thus, the current strategy with identical treatment for all soft tissue sarcomas is far from satisfactory. In this study, we first reviewed the current clinical and genomic findings of soft tissue sarcoma, paying special attention to the heterogeneities among different tumors. Then we reviewed the state-of-art understanding of targeted therapy in soft tissue sarcoma. We observed tremendous heterogeneity both in clinical and genomic settings between different tumors. Individualized treatment plans demonstrated better response and disease control and should be advocated. In summary, heterogeneity of soft tissue sarcomas requires the development of individualized treatment plans such as targeted therapy.

A phase II study of pazopanib as front-line therapy in patients with non-resectable or metastatic soft-tissue sarcomas who are not candidates for chemotherapy

BACKGROUND

Cytotoxic chemotherapy remains the standard of care first-line treatment for advanced and metastatic soft-tissue sarcomas (STSs). Certain patients may not be chemotherapy candidates based upon age or co-morbidities, leaving limited treatment options. Pazopanib is a multi-targeted tyrosine kinase inhibitor that is FDA-approved for metastatic STS after the first line. We proposed a phase II study evaluating pazopanib as a first-line agent in patients with advanced disease who are deemed not to be candidates for chemotherapy.

METHODS

Eligible patients were at least 18 years old, not candidates for chemotherapyand were treatment naive. Pazopanib was titrated from 200 mg twice daily to a goal of 800 mg daily. The primary end point was the clinical benefit rate (CBR) (CBR = completed response + partial response + stable disease per Response Evaluation Criteria in Solid Tumours [RECIST 1.1]) at 16 weeks. The sample size of 56 evaluable patients was calculated to provide 80% power to test a hypothesised CBR of ≥35% against an unfavourable CBR of ≤20%. If ≥ 17 patients achieved benefit, the null CBR of 20% would be rejected at a nominal 5% alpha level. Secondary end points included progression-free survival (PFS), overall survival (OS), quality of life and serum biomarkers.

FINDINGS

Fifty-six patients were enrolled from May 2015 to February 2019 and are included in the intention-to-treat analysis. Median PFS was 3.67 (2.62-7.25) months. Median OS was 14.16 (95% confidence interval [CI]: 8.4-NR) months, CBR = 39.29% (22/56) (CI = 0.265-0.533, p = 0.0007). No new or unexpected adverse events were seen. The most common grade I-II events were diarrhoea, nausea and fatigue. The most common grade III-IV events were hypertension and liver function test abnormalities.

INTERPRETATION

These data suggest that there is a benefit to front-line pazopanib in patients with STS who are not candidates for cytotoxic chemotherapy.

Secondary Sarcomas: Biology, Presentation, and Clinical Care

Secondary sarcomas are a subset of sarcomas that occur in patients with prior cancer diagnoses and are associated with environmental or genetic factors. Although secondary sarcomas are rare in general, there are predisposing factors that can substantially increase this risk in certain populations. Herein, we review the environmental factors with the strongest association of sarcoma risk, including chemical exposure, certain viruses, cytotoxic and immunosuppressive agents, chronic edema, and radiation exposure. Additionally, the most common genetic disorders that carry a predisposition for sarcoma development will be discussed, including hereditary retinoblastoma (RB), Li-Fraumeni syndrome (LFS), neurofibromatosis type 1 (NF1), and DICER1 syndrome. Although treatment does not generally differ for sporadic versus secondary sarcomas, awareness of the risk factors can alter therapeutic strategies to minimize risk, aid prompt diagnosis by increasing clinical suspicion, and allow for appropriate surveillance and genetic counseling for those patients with cancer predisposition syndromes.