Degeneration of Paget's disease into sarcoma: clinical and therapeutic influencing factors.

We analysed a series of 119 patients presenting with Paget's bone disease treated at the Istituto Ortopedico Rizzoli (Bologna Italy) over 35 years (from 1970 to 2006). Among these, we found 18 cases that had degenerated into sarcoma. The first goal of this study was to underline the potential factors of Paget's disease transformation into sarcoma. In detail we considered: age, gender, duration of disease, clinical expression, levels of total alkaline phosphatase and type of therapy. The results highlighted an interesting correlation between therapy and degeneration into sarcoma; more specifically, malignant transformation occurred both in patients who had not received any therapy and those who had received regular calcitonin treatment; otherwise, no sarcoma degeneration occurred in the patients treated with bisphosphonates. These data seem to indicate a preventing effect of bisphosphonates towards the degeneration of Paget's disease into sarcoma.