Clear cell sarcoma : a retrospective review from a tertiary orthopaedic sarcoma unit

The aim of this study was to assess the presentation, investigation and management of patients with a clear cell sarcoma within a single-centre, tertiary bone tumour unit, reporting the rates of survival, local recurrence, and metastases.

The study involved a retrospective review of a prospectively maintained oncology database, from which we identified and included 47 patients who were referred and treated for a clear cell soft-tissue sarcoma at our unit between January 1996 and January 2024. The median follow-up was 28 months (IQR 13.5 to 71.5). The primary outcome measure was survival and secondary outcomes included the rates of local recurrence and the development of metastases.

The overall survival for all patients was 61.9% at two years (95% CI 49.1 to 78.1), 45.7% at five years (95% CI 32.6 to 64.1), and 37.4% at ten years (95% CI 24.1 to 57.9). The median survival was 40 months. At the time of presentation, metastases were found in 13 patients (28%), in whom radionuclide imaging with positron emission tomography (PET) CT allowed better identification. More than half of the patients who were referred from elsewhere had prviously undergone an unplanned excision, although this did not seem to influence the mortality outcomes. Excision of the tumour and/or local disease was the primary treatment, with curative intent in 37 patients (78.7%). Local recurrence and metastases after the primary treatment was noted in seven (19%) and 16 (43%) patients, respectively, with a wide range of timing (1 to 73 months). Primary excision with disease-free margins gave the best chance of cure.

Clear cell sarcoma is an aggressive tumour. The rate of survival remains modest. The early identification of metastases using PET CT allowed for more focused treatment. The local follow-up protocol must appreciate the wide variations in the time to recurrence. Targeted immunological systemic treatments may improve the outcomes in the future.