The impact of local control in the treatment of children with advanced infantile and adult-type fibrosarcoma: Experience of the cooperative weichteilsarkom studiengruppe (CWS).

This study aims at examining the potential survival benefits of primary versus secondary surgery of children diagnosed with advanced infantile (iFS) and adult-type fibrosarcoma (aFS). Treatment and outcome of 89 children with FS treated within prospective Cooperative Studiengruppe (CWS) trials (1981–2016) were analyzed retrospectively. Localized disease (LD) was diagnosed in 87 patients: 64/66 patients with iFS (≤ 2 years) and 23 with aFS (> 2 ≤ 18 years). Two patients (iFS) had metastatic disease. Resection was the mainstay of therapy of patients with LD resulting in microscopically complete (R0, IRS group I) (n = 29/87, 33%), microscopically incomplete (R1, IRS group II) (n = 17/87, 20%) and macroscopically incomplete (R2, IRS group III) (n = 41/87, 47%). Advanced LD (IRS group III) was present in 32/64 (50%) patients with iFS and in 9/23 (39%) with aFS. Chemotherapy was added predominantly in patients with advanced disease and an assessable objective response to CHT was seen in 71% iFS and 75% aFS. The 5-year event-free survival (EFS) of patients with iFS and aFS was 81% (± 10, 95% CI) and 70% (± 19, 95% CI) (p = 0.24); the 5-year overall survival (OS) was 98% (± 3, 95% CI) and 82% (± 16, 95% CI) (p = 0.02). Primary resection was no prognostic factor. Secondary R0/ R1 resection in patients with advanced disease improved 5-year EFS and OS in aFS (p = 0.002 and p = 0.000) but not in infants. Secondary resection improves outcome in advanced aFS but not in infants. Mutilating surgery in infants should be avoided. Treatment study: patients were enrolled in five prospective studies and one registry, prognosis study: retrospective study. II/ III. Fibrosarcoma is a very rare malignant tumor. Little is known about differences of local treatment of advanced infantile and adult-type. Data of 89 patients registered in five prospective trials and one registry of the Cooperative Weichteilsarkom Studiengruppe (CWS) (1981–2016) were analyzed. [ABSTRACT FROM AUTHOR]