Poor prognostic features among soft tissue sarcoma patients: analysis based on the first sarcoma registry in South Africa

Abstract

Background: Soft tissue sarcomas (STS) of the extremities are rare tumours with various prognostic factors. The epidemiology of STS is understudied in South Africa. Here we present the first data on extremity STS from the South African Sarcoma Registry.

Methods: The study comprised a retrospective review of extremity, pelvis and trunk wall STS patients collected from 2019 to 2023 in a prospective South African Sarcoma Registry. One hundred and three STS patients were referred to the orthopaedic oncology unit from 2019 to 2023 and, after exclusion of 14 patients with well-differentiated liposarcomas, data for 89 patients were analysed. To assess survival post-diagnosis, the South African Medical Research Council (SAMRC) National Population Death Registry (Burden of Disease Research Unit) was scrutinised using patient ID numbers. Only patients with ID numbers were utilised for two-year survival curve analysis. To assess factors associated with two-year survival rate, a univariate and multivariate Cox regression analysis was performed.

Results: The median age of the cohort was 49 years; the median tumour size was 11 cm; and metastasis was present at diagnosis in 17% of the cohort. Furthermore, less than half were referred before biopsy or surgery, and 10% were not operated due to metastatic disease at presentation. Overall two-year survival proportion for all patients was 0.70, and for those without metastasis at diagnosis it was 0.80. The two-year survival estimates for patients referred ‘untouched’ was 0.83, and for those referred with history of prior biopsy or surgery was 0.76. Tumour size was the only factor with a significant impact on two-year survival rates for patients without metastasis at diagnosis (p < 0.001).

Conclusion: In our registry, STS patients had more poor prognostic features compared to Scandinavian registry data. Patients tended to present younger, with larger tumours and more frequent metastasis at diagnosis. Generating clinical data through a prospective and consecutive accrual of patients into a registry is paramount for assessment of quality of care and for clinical research.

Level of evidence: 3