Patterns of Care and Outcomes in Patients With Metastatic Bone Tumors (METABONE)

Bone tumors make up about 3-5% of childhood cancers and less than 1% of cancers in adults. Of these, osteosarcoma (OSS) is the most commonly diagnosed primary malignant bone tumor. OSS is a primary mesenchymal malignant tumor of bone characterized by the production of osteoid or immature bone by the malignant cells. Despite its rarity, OSS is the most common primary malignancy of bone in children and adolescents, and the fifth most common malignancy among adolescents and young adults aged 15 to 19 years.

Ewing sarcoma (ES) is the second most frequent bone tumors in children and may arise also in soft tissues. This disease encompasses tumors formerly known as Askin's tumor, Peripheral Neuroectodermal Tumor (PNET) and the Ewing Sarcoma Family of Tumors (ESFT).

Chondrosarcoma are rare sarcoma reputed chemorefractory in the non-operable setting and for which little is known in terms of palliative management with systemic treatments.

Despite adequate loco-regional treatment, up to 40% of patients with sarcoma, soft tissue or bone, will develop metastatic disease. When metastases are detected, the standard of care is based on palliative chemotherapy with a median survival in this setting of only 18 months.

A slight improvement has been obtained over years thank to registration of a couple of drugs such as Trabectedin and Pazopanib, the first antiangiogenic registered for soft tissue sarcoma patients. Pazopanib is routinely prescribed worldwide after failure of first line chemotherapy in soft tissue sarcoma. However, bone tumors have not benefited from these small advances yet and treatment still rely on chemotherapy combining doxorubicine cisplatinum and ifosfamide. There is no standard in relapse and palliative settings, and after failure of these agents the survival is very poor. Bone sarcomas are therefore tumors with very little available data and low level of evidence on palliative systemic treatments in clinical trials and in the real life setting.

The primary objective of the METABONE study is to conduct a retrospective descriptive analysis of clinic-biological profiles, patterns of care and modalities of treatment for a set of patients with malignant bone tumors in a real-life national setting.