Zoledronic acid in metastatic chondrosarcoma and advanced sacrum chordoma: two case reports

Zoledronic acid was used in a 63-year-old man with metastatic chondrosarcoma and in a 66-year-old woman with a diagnosis of sacrum chordoma both reporting severe pain related to tumor.In the first case, zoledronic acid was able to maintain pain control despite disease progression following chemotherapy, in the other case, zoledronic acid only produced significant clinical benefit.Control of pain associated with bone tumors such as chondrosarcoma and chondroma may significantly improve from use of zoledronic acid, independently from tumor response to other treatments. Evaluation on larger series are needed to confirm the clinical effect of this bisphosphonate on such tumors.Malignant tumors arising from the skeletal system are rare, representing only 0.2% of all new cancers [1]. Bone tumors are classified by cell type and recognized products of proliferating cells. Chondrogenic tumors account for about 21% of bone tumors. Chondrosarcoma is a malignant cartilage forming tumor. Conventional chondrosarcoma is the most frequent type of chondrosarcoma and may develop centrally within the medullary cavity (primary or central chondrosarcoma) or within the cartilage cap of a pre-existing osteochondroma (secondary or peripheral chondrosarcoma). Most chondrosarcomas develop in the thoracic, pelvic and long bones. Grade is the single most important predictive factor for local recurrence and metastasis. Chordoma arises from remnants of notochord and is very rare representing about 3% of bone tumors. Chordomas are characteristically distributed throughout the midline with 50% occurring in the sacrococcygeal region, approximately 35% in the skull base and about 15% in the mobile vertebral column [2]. Both tumors may have a severe prognosis when advanced because of limited curative therapies, poor functional outcome and severe pain. When feasible, aggressive surgery represents the best chance of cure. However, recurrence rate are high. Resistance to chemotherapy makes even more dif