Primary malignant bone tumours: Epidemiological data from an Orthopaedic Oncology Unit in South Africa

Abstract

INTRODUCTION: Limited data is available with regard to the epidemiology of primary malignant orthopaedic tumours in the South African clinical setting. As a result, orthopaedic surgeons have to rely on data from other countries when formulating differential diagnoses for malignant bone lesions. Existing data, however, demonstrates variance in the incidence between different geographic regions. By analysing the tumour epidemiology at our centre and comparing it to published data from other parts of the world, we aim to better define the local prevalence of primary malignant bone tumours. Materials and methods: A retrospective review of all patients with biopsy confirmed malignant primary bone tumours that presented between January 2008 and June 2015 were conducted. Patients with multiple myeloma and lymphoma were excluded. Epidemiological data pertaining to patient demographics, tumour location and histological diagnosis were recorded and analysed. RESULTS: Included for review were 117 patients with biopsy-confirmed primary malignant bone tumours. Tumours involving the proximal humerus, distal femur, proximal tibia and pelvis accounted for 80% of all tumours. Osteosarcoma was the most common histological diagnosis (72.6%) and higher than reported figures from any other country. It was followed by chondrosarcoma (11.4%), Ewing's sarcoma (9.4%), spindle cell sarcoma (4.2%) and malignant giant cell tumour (GCT) (1.7%). A single patient was diagnosed with adamantinoma. HIV infection had no significant association with primary bone tumour incidence. CONCLUSION: Epidemiological data from this review reflect small but significant differences compared to international literature. The incidence of osteosarcoma appeared to be higher than in previous reports from other regions. Future study in this area may identify a reason for this difference, socio-economic reasons may be responsible.