Prognosis of osteosarcomas in the mandible: 15-year experience of 55 patients

Our goal was to evaluate the prognosis of osteosarcomas (OS) in the mandible for finding out the best treatment. Patients diagnosed with OS in the mandible from January 2000 to December 2015 were retrospectively enrolled. Demographic, tumor-specific, treatment, and survival data were collected and analyzed. A total of 55 patients (35 male and 20 female) were included, all patients had first manifestation of swelling. Cachexia occurred in 15 (27.3%) patients. Chondroblastic type was the most common histology subtype followed by osteoblastic type. High grade tumors were found in 30 (63.6%) patients. 33 (60%) patients received an operation of hemimandibulectomy, and free fibula reconstruction was performed in 20 (36.4%) patients. The 5-year recurrence-free survival (RFS) and disease-specific survival (DSS) rates were 73.6% and 66.9%, respectively. Univariate prognostic analysis reported risk factors of tumor grade, reconstruction type (free fibula flap vs non-free flap), and operation extent were significant for the recurrence, and reconstruction type and operation extent were significant for the disease-specific death, but in multivariate analysis, only the factor of operation extent was significantly associated with both the recurrence and death. A wide excision extent such as hemimandibulectomy is suggested for OS in the mandible for achieving good prognosis.