Paget's osteosarcoma and post-radiation osteosarcoma: secondary osteosarcoma at Middlemore Hospital, New Zealand.

ABSTRACT

AIMS: To review the clinical and histological features of our cases of Paget's osteosarcoma and post-radiation osteosarcoma. METHODS: A search through the files of the New Zealand Bone and Soft Tissue Tumour Registry was performed, patients were identified and the relevant details were collated. RESULTS: Thirty-one cases of Paget's osteosarcoma and eight cases of post-radiation osteosarcoma were identified. Patients with Paget's osteosarcoma were aged between 48 and 67 years, predominantly female, and axial and appendicular skeleton were equally affected. The outcome was known in 29 cases, with a median survival of 7.25 months and 5 year overall survival of 10%. Patients with post-radiation osteosarcoma were aged between 17 and 68 years, equally male or female, and axial and appendicular skeleton were equally affected. Index lesions included benign or malignant osseous and non-osseous conditions. The average age at diagnosis of the index lesion was 30.1 years and the average latent period was 13.5 years. The outcome was known in all eight cases, with a median survival of 33 months and 5 year overall survival of 38%. CONCLUSIONS: Paget's osteosarcoma and post-radiation osteosarcoma are examples of secondary osteosarcoma. The former affects elderly patients, and has a poor prognosis and response to treatment. The later affects a wide age group, and has a prognosis and response to treatment comparable with primary osteosarcoma.