Non-rhabdomyosarcoma soft-tissue sarcoma

PET/CT and PET/MR in Soft Tissue Sarcoma: An Update

Soft tissue sarcomas account for 6%-8% of pediatric cancers. The rhabdomyosarcoma family is the most frequent soft tissue sarcoma in this age group accounting for 3% of pediatric cancers. Rhabdomyosarcomas are high-grade tumors with a high propensity to metastasize. The risk-adapted, multimodal therapeutic approach for rhabdomyosarcomas incorporates a combination of surgery, radiotherapy, and multi-agent cytotoxic chemotherapy. Soft tissue sarcomas other than rhabdomyosarcoma account for 3%-4% of pediatric cancers. The nonrhabdomyosarcoma soft tissue sarcomas include both low-grade and high-grade tumors. While surgery is the mainstay of therapy in most non-rhabdomyosarcoma soft tissue sarcomas, many cases require a multimodal therapeutic approach including radiotherapy and chemotherapy. In North America, most pediatric patients with soft tissue sarcomas are treated in Children's Oncology Group clinical trials. In this article, we will primarily focus on the staging, risk stratification, imaging recommendations, and interpretations in accordance with the Children's Oncology Group trials. We will review the results and recommendations of International Soft Tissue Sarcoma Database Consortium and European trials in relevant sections where they provide complementary guidelines.

Proton Therapy in Non-Rhabdomyosarcoma Soft Tissue Sarcomas of Children and Adolescents

This paper provides insights into the use of Proton Beam Therapy (PBT) in pediatric patients with non-rhabdomyosarcoma soft tissue sarcomas (NRSTS). NRSTS are a heterogeneous group of rare and aggressive mesenchymal extraskeletal tumors, presenting complex and challenging clinical management scenarios. The overall survival rate for patients with NRSTS is around 70%, but the outcome is strictly related to the presence of various variables, such as the histological subtype, grade of malignancy and tumor stage at diagnosis. Multimodal therapy is typically considered the preferred treatment for high-grade NRSTS. Radiotherapy plays a key role in the treatment of children and adolescents with NRSTS. However, the potential for radiation-induced side effects partially limits its use. Therefore, PBT represents a very suitable therapeutic option for these patients. The unique depth-dose characteristics of protons can be leveraged to minimize doses to healthy tissue significantly, potentially allowing for increased tumor doses and enhanced preservation of surrounding tissues. These benefits suggest that PBT may improve local control while reducing toxicity and improving quality of life. While clear evidence of therapeutic superiority of PBT over other modern photon techniques in NRSTS is still lacking-partly due to the limited data available-PBT can be an excellent treatment option for young patients with these tumors. A dedicated international comprehensive collaborative approach is essential to better define its role within the multidisciplinary management of NRSTS. Shared guidelines for PBT indications-based on the patient's age, estimated outcome, and tumor location-and centralization in high-level referral centers are needed to optimize the use of resources, since access to PBT remains a challenge due to the limited number of available proton therapy facilities.

Local treatment in initially unresected non-rhabdomyosarcoma soft-tissue sarcomas of children and adolescents: A retrospective single-center experience

BACKGROUND

Pediatric non-rhabdomyosarcoma soft-tissue sarcomas (NRSTS) are a heterogeneous group of aggressive tumors. Patients with locally advanced/initially unresected disease represent a subset of patients with unsatisfactory outcome: limited data are available on the best treatment approach, in particular regarding local therapy.

METHODS

This retrospective analysis concerned 71 patients < 21 years old with nonmetastatic, initially unresected adult-type NRSTS, treated at a referral center for pediatric sarcomas from 1990 to 2021. Patients were treated using a multimodal approach, based on the protocols adopted at the time of their diagnosis.

RESULTS

The series included a selected group of patients with unfavorable clinical characteristics, i.e., most cases had high-grade and large tumors, arising from axial sites in 61% of cases. All patients received neoadjuvant chemotherapy, 58 (82%) had delayed surgery (R0 in 45 cases), and 50 (70%) had radiotherapy. Partial response to chemotherapy was observed in 46% of cases. With a median follow-up of 152 months (range, 18-233), 5-year event-free survival (EFS) and overall survival (OS) were 39.9% and 56.5%, respectively. Survival was significantly better for patients who responded to chemotherapy, and those who had a delayed R0 resection. Local relapse at 5 years was 7.7% for patients who did not undergo delayed surgery.

CONCLUSIONS

Our series underscores the unsatisfactory outcome of initially unresected NRSTS patients. Improving the outcome of this patient category requires therapeutic strategies able to combine novel effective systemic therapies with a better-defined local treatment approach to offer patients the best chances to have R0 surgery.

Clinical presentation of childhood soft tissue sarcomas: a systematic review and meta-analysis

BACKGROUND

Time to diagnosis (TTD) of childhood soft tissue sarcoma (STS) is significantly associated with survival. This review aims to identify pre-diagnostic symptoms/signs to inform earlier diagnosis interventions.

METHODS

Medline, Embase, Cochrane and Web-of-Science were searched between January 2010 and February 2021 for studies including children (<18 years) diagnosed with STS, with no language restrictions. Pooled proportions of symptoms/signs were calculated and subanalysed by tumour location and age.

RESULTS

Fifty-nine eligible studies were identified, totalling 2462 cases. The most frequent symptoms were lump/swelling (38%, 95% CI 27% to 51%), pain (6%, 95% CI 3% to 10%), cutaneous changes (4%, 95% CI 0 to 9%), localised eye swelling (3%, 95% CI 0 to 7%), cranial nerve deficits (2%, 95% CI 0 to 5%) and constitutional symptoms (2%, 95% CI 0 to 5%).Symptoms varied by location and age. Localised eye swelling (20%, 95% CI 3% to 45%), cranial nerve deficits (14%, 95% CI 4% to 28%) and impaired visual function (6%, 95% CI 0 to 17%) were frequent in head and neck tumours. For abdomen/pelvic tumours, urinary symptoms (24%, 95% CI 5% to 15%), abdominal distension/discomfort (22%, 95% CI 4% to 47%), genital lump/swelling (16%, 95% CI 1% to 42%), constitutional symptoms (9%, 95% CI 0%] to 23%), vaginal bleeding (7%, 95%C I 0 to 21%) and bowel habit changes (6%, 95% CI 0 to 17%) were frequent.In <5 years, consumptive coagulopathy (16%, 95% CI 0 to 48%), cutaneous changes (5%, 95% CI 0 to 40%), genital lump/swelling (4%, 95% CI 0 to 14%), reduced mobility (3%, 95% CI 0 to 11%), vaginal bleeding (2%, 95% CI 0 to 11%) and bleeding/bruising/petechiae (2%, 95% CI 0 to 20%) were frequent compared with lump/swelling, constitutional symptoms, pain and headaches which were frequent among >11 years.

CONCLUSIONS

For STS, pre-diagnostic symptoms differ by age and location, highlighting the need to tailor early diagnosis interventions.

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.

Pediatric Non-Rhabdomyosarcoma Soft Tissue Sarcomas: Standard of Care and Treatment Recommendations from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

This paper describes the standard of care for patients with non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) and the therapeutic recommendations developed by the European paediatric Soft tissue sarcoma Study Group (EpSSG). NRSTS form a very mixed group of mesenchymal extraskeletal malignancies. Their rarity, heterogeneity, and aggressiveness make the management of children and adolescents with these tumors complex and challenging. The overall cure rate for patients with NRSTS is around 70%, but survival depends on several prognostic variables, such as histotype and tumor grade, extent of disease and stage, tumor size, and tumor site. While surgery remains the mainstay of treatment for most of these tumors, a multimodal therapeutic approach including radiotherapy and chemotherapy is required in many cases. The EpSSG NRSTS 2005 study was the first prospective protocol tailored specifically to NRSTS. Together with the ARST0332 study developed by the North-American Soft Tissue Sarcoma Committee of the Children's Oncology Group (COG), the EpSSG NRSTS 2005 study currently represents the benchmark for these tumors, establishing risk-adapted standards of care. The EpSSG has developed common treatment recommendations for the large group of adult-type NRSTS (including synovial sarcoma), and specific treatment recommendations for other particular adult-type histologies (ie, alveolar soft-part sarcoma, clear cell sarcoma and dermatofibrosarcoma protuberans); other highly malignant tumors with a biology and clinical behavior differing from those of adult-type NRSTS (ie, rhabdoid tumors and desmoplastic small round cell tumor); and soft tissue tumors of intermediate malignancy (ie desmoid-type fibromatosis, inflammatory myofibroblastic tumors, and infantile fibrosarcoma). New effective drugs are needed for patients whose NRSTS carries the worst prognosis, ie, those with unresectable tumors, metastases at diagnosis, or relapsing disease. Progress in this area relies on our ability to develop international integrated prospective collaborations, both within existing pediatric oncology networks and, importantly, between the communities of specialists treating pediatric and adult sarcoma.