Descriptive Epidemiology of Malignant primary Osteosarcoma in Tunisia 1980-2016

Background: Osteosarcoma is a rare malignant tumor of the mesenchymal tissue that accounts for 5% of all malignant tumors in children and teenager. The purpose of our study was to describe the epidemiological and evolutionary characteristics of osteosarcoma in Tunisia. Methods: It’s a retrospective study performed in the Oncology Department of Salah Azaiez Institute from January 1980 to December 2016. We analyzed records of 200 cases of patients with primary high-grade osteosarcoma. Results: The mean incidence was 6 cases per year. The mean age at the time of diagnosis was 19 years with a slight male predominance (55%). The distribution had a single peak during adolescence and a plateau during adulthood. The average consultation period was 3.4 months. The most common reasons for consultation were the pain (82%), followed by swelling (74%), trauma (10%), fracture (6.5%), and functional impairment (5.5%). Mean tumor size was 11 cm. Preferred site was long bones in young patients and flat bones in elderly ones. Common osteosarcoma was the most frequent (85%). Overall survival and progression-free survival at 5 years were respectively 78% and 90.5%. Conclusion: In summary, this study is a large national population-based incidence report of osteosarcoma in Tunisia.