High-grade undifferentiated pleomorphic sarcoma of pelvis treated with curettage and bone graft after complete remission following caffeine-potentiated chemotherapy

Undifferentiated pleomorphic sarcoma (formerly known as malignant fibrous histiocytoma: MFH) is a relatively rare primary malignant bone tumor first described by Norman and Feldman [1] as a malignant histiocytoma. It comprises approximately 6% of all bone tumors [2, 3]. It was reported that the osteosarcoma adjuvant or neoadjuvant chemotherapeutic regimen is beneficial [4], and a good pathological response predicted better disease-free survival [5]. Caffeine is a xanthine analog that has a biochemical modulating effect as an inhibitor of DNA repair, and may inhibit the post-replication repair of sublethally damaged DNA [6, 7]. Caffeine-potentiated chemotherapy has been administered to patients with high-grade bone and soft-tissue sarcomas since 1989, because caffeine enhances the cytocidal effects of anticancer drugs through the inhibition of DNA repair. Approximately 15% of primary malignant bone tumors involve the pelvic girdle [8]. Periacetabular lesions are the most difficult sites to reconstruct because of their complicated anatomical structure, and complication rates-including deep infection (12-47%), implant dislocation (2-22%), or local recurrence (28-35%)-are still high in pelvic lesions [9-13].