Primary Osteosarcoma in Patients Over 75 Years of Age: A Case Series and Literature Review

Background/Aim: Little is known about the clinical characteristics in older patients of >= 75 years of age with primary osteosarcoma due to its rarity. We aimed to understand the clinical characteristics in these patients in order to make an appropriate diagnosis and provide treatment. Patients and Methods: The medical records of eight patients of >= 75 years of age with primary osteosarcoma were retrospectively reviewed. We investigated their clinical features, imaging findings, histopathological findings, treatment methods, and oncological outcomes. Results: There were two male and six female patients, with a mean age of 80 years. The mean follow-up period was 44 months. The initial symptom was pain in five, swelling in two, and a mass in one. The initial diagnosis was osteoarthritis in two, lumbar canal stenosis in two, benign bone tumor in four. The mean period from the first time the patient noticed symptoms to referral was 25 months. Two patients had a history of surgical curettage at their previous hospital for bone tumor that was considered benign. Lung metastasis was observed at presentation in three patients. The mean tumor size was 129 mm in its greatest dimension. Surgical treatment was performed on six patients, including frozen autograft reconstruction in one. Carbon-ion radiotherapy was conducted in one patient due to an unresectable pelvic lesion. Conclusion: Diagnosis requires care because the radiological and histological findings of primary osteosarcoma in patients >= 75 years of age are often non-specific, in addition to their delayed consultation. Individualized treatment including surgical procedure and radiotherapy is essential for older patients to maintain a good quality of their lives.