Dedifferentiated chondrosarcoma: prognostic factors and outcome from a European group.
Dedifferentiated chondrosarcoma has a very poor prognosis. Because of its rarity, there are few large studies of outcome which might identify potential prognostic factors. In particular there remains uncertainty about the value of chemotherapy for this condition. A retrospective study was done using data supplied by members of the European Musculo Skeletal Oncology Society (EMSOS). We obtained data on 337 patients from nine European centres with this rare condition, with details on patients, treatment and outcome which were then analysed in an attempt to identify prognostic features. The median age was 59 years and there was a slight predominance of males (53%). The most common sites were the femur and pelvis. Twenty-nine percent of patients with a long bone tumour had a pathological fracture. 71 patients (21%) had metastases at the time of diagnosis and these patients had a median survival of 5 months with a 10% chance of survival at 2 years. For the 266 patients without metastases at diagnosis, 254 underwent surgery with 79% having limb salvage. Thirty-one percent of these 266 patients had chemotherapy with 47% of those under 60 receiving it. In this group of 266 patients, overall survival was 28% at 10 years and poor prognostic factors were the presence of a pathological fracture at diagnosis, a pelvic location and increasing age. Local recurrence and overall survival were related to inadequate margins of excision. We did not find that the histological subtype, size of the tumour or the use of chemotherapy significantly affected outcome. For all patients the overall survival was 24% at 5 years. The prognosis for patients with dedifferentiated chondrosarcoma remains dismal. Surgery with clear margins remains the principal treatment for this condition. Further use of chemotherapy should be within a trial or treatment protocol.