Dermatofibrosarcoma protuberans in children and adolescents: The European Paediatric Soft Tissue Sarcoma Study Group prospective trial (EpSSG NRSTS 2005)

Abstract

Background As dermatofibrosarcoma protuberans (DFSP) are rare with no prospective series within paediatric sarcoma trials, the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG) examined the clinical data and outcomes of DFSP enrolled in a multinational study of non‐rhabdomyosarcoma soft tissue sarcomas (NRSTS). Patients and methods Forty‐six patients with confirmed DFSP were enrolled into the EpSSG NRSTS 2005 study. All had surgical resection and none had any further therapy at diagnosis. Results The median age at diagnosis was 6.9 years (range 0.4‐17.5). All patients had localised disease, and the majority had small <5 cm tumours (93%), and 76% had Intergroup Rhabdomyosarcoma Study (IRS) I tumours. All patients had up front surgery, 32 requiring two operations. There were 11 patients with IRS II tumours, of which only two went on to have a local recurrence. After a median follow up of 49.0 months (range 4.2‐130.9), all patients were alive at the time of this report, with 5‐year event‐free survival of 92.6% (CI 78.8‐97.6) with a 100% overall survival. Conclusion This report demonstrates the ability to run prospective paediatric studies in NRSTS in multiple European countries, with reasonable numbers of DFSP patients, with few events and no deaths, and hence excellent outcomes.

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

“…DFSP occurring in children is often reportedly a low-grade, small, superficial tumor, completely resected at diagnosis in most cases. 31 , 86 Advanced unresectable or metastatic cases are extremely uncommon in pediatric age, as well as the transformation to high-grade fibrosarcoma. Targeted therapy has proven effective medical treatment in such cases.…”

“…19 In terms of rationale, patient stratification and treatment paradigms (based on both pediatric and adult experiences), the EpSSG NRSTS 2005 study was very similar to the ARST0332 study developed by the North-American Soft Tissue Sarcoma Committee of the Children's Oncology Group (COG), conducted from 2007 to 2012. 20 The EpSSG has already reported on its analyses of various specific histological subgroups, [21][22][23][24][25][26][27][28][29][30][31][32] and on the results of treatment in the whole series of patients enrolled in the prospective non-randomized part of the protocol. 19 Table 1 shows the main findings they published.…”

Dermatofibrosarcoma protuberans, fibrosarcomatous variant: A rare tumor in children

“…The 5-year survival rate is close to 100% for children and adolescents. 4 However, FS transformation worsens the prognosis significantly, with a higher risk of local recurrence…”

Hybridtumor eines Riesenzellfibroblastoms und eines Dermatofibrosarcoma protuberans

“…Das DFSP tritt am häufigsten in der Altersgruppe zwischen 25-45 Jahren auf, es kann aber alle Altersgruppen betreffen. In der europäischen Registerstudie EpSSG NRSTS 2005, in der Patienten mit einem DFSP mit einem Alter bis zu 21 Jahren eingeschlossen wurden, betrug der Anteil der bis zu einem Jahr alten Patienten 6,5 % [8]. Prädilektionsstellen sind der Stamm und die proximalen Extremitäten.…”