Late post-operative recurrent osteosarcoma: Three case reports with a review of the literature

Abstract
The aim of the present study was to investigate the clinical characteristics and treatment of late recurrent osteosarcoma following surgery. The cases of three patients with late recurrent osteosarcoma, who were treated at the General Hospital of Jinan Military Command, General Hospital of Nanjing Military Command and Xinan Hospital of The Third Military Medical University, were analyzed retrospectively. Furthermore, 10 cases of late recurrent osteosarcoma were retrieved from the literature. In total, eight male and five female cases were selected for the present study. The mean age at recurrence was 25.56 years (range, 13‑42 years). The locations of the osteosarcomas were as follows: five cases in the distal femur, two cases in the distal tibia and acetabulum, respectively, and one case in the proximal tibia (the remaining cases were not described). The tumors were histologically classified into three cases of fibroblastic, two cases of traditional‑type; two cases of mixed‑type and one case each of osteoblastic‑, chondroblastic‑ and telangiectasia‑type osteosarcoma (the remaining cases were not described). The mean recurrence time following surgery was 10.02 years (range, 5.2‑19.3 years). With regard to the treatment modalities, five patients accepted surgery and chemotherapy, one patient accepted surgery and radiotherapy, two patients accepted surgery alone and one patient did not complete the treatment (the remaining cases were not described). From the 12 cases that were followed-up for between 0.5 and 4.7 years (mean, 2.28 years), one case was lost to follow-up, six patients survived (up to 4.5 years) and six patients succumbed to their condition (0.6‑4.7 years). The present study highlights the fact that more focus should be placed upon the long‑term follow‑up of patients with osteosarcoma. A follow‑up is required once every six months, from five years after the diagnosis. The abnormal changes in the surgical site should also receive further attention, in addition to the pulmonary and systemic metastases. Following a diagnosis of late post‑operative recurrence, surgery and post‑operative chemotherapy are commonly used in clinical treatment, however, the clinical outcome of osteosarcoma requires further observation.