Low grade chondrosarcoma : is long-term follow-up necessary?

Abstract

INTRODUCTION: Currently, the follow-up regimen for patients treated for low-grade chondrosarcoma is similar to that of all chondrosarcomas. It is possible that low-grade chondrosarcoma may have a far more benign course than other chondrosarcomas and, if treated adequately, may require a far less vigorous follow-up regimen. PATIENTS AND METHODS: A retrospective study was performed on all patients treated for chondrosarcoma at the Pretoria Musculoskeletal Tumour Unit,, University of Pretoria, over a 22-year period, between 1987 and 2009. In total 56 patients were treated for chondrosarcoma over this period, but two patients were lost to follow-up. The study totalled 54 patients. The grade of chondrosarcoma, outcome and tumour recurrence was evaluated in these patients. The lesions were divided into four histological grades: atypical enchondroma (grade 0), low-grade chondrosarcoma (grade I), intermediate grade chondrosarcoma (grade II), and high-grade chondrosarcoma (grade III). RESULTS: Histologically 46 tumours were low-grade (grade 0 or I) chondrosarcoma (82%), there were nine cases of intermediate (grade II) chondrosarcoma (16%), and one patient had a metastatic mesenchymal chondrosarcoma. The femur and humerus were the commonest sites involved. The axial skeleton was affected in only three cases, all of which had more aggressive lesions. Two patients died, one with metastatic mesenchymal chondrosarcoma involving the scapula, and the other with an intermediate (grade 2) lesion of the pelvis. There was no tumour recurrence in 49 patients after a mean period of 57.5 months, of which 42 patients had low-grade (grade 1) lesions, and seven patients had intermediate (grade 2) lesions. Two patients with low-grade lesions were lost to follow-up. Three patients presented with recurrence, all of which had a local recurrence. No metastatic disease was detected radiographically. Of these three patients one had a grade 2 lesion, and the other two patients were initially not treated with surgical adjuvant therapy. Not one patient with low-grade chondrosarcoma treated adequately with local curettage and surgical adjuvant therapy presented with local recurrence or distal metastasis.CONCLUSION: We believe that adequately treated low-grade chondrosarcomas have a very low local recurrence rate. Treatment consists of local curettage with surgical adjuvant therapy. When faced with recurrence, it rarely presents with distant metastases. A revised follow-up schedule is advised consisting of visits at 3 and 6 months and followed by yearly visits for 5 years. This appears to be adequate for timely detection and treatment of any local recurrence of low-grade chondrosarcoma.