The impact of biopsy sampling errors and the quality of surgical margins on local recurrence and survival in chondrosarcoma

Sandro Hodel,1 Christoph Laux,1 Jan Farei-Campagna,1 Tobias Götschi,1 Beata Bode-Lesniewska,2 Daniel Andreas Müller1 1Orthopaedic Department, Balgrist University Hospital, Zürich, Switzerland; 2Department of Pathology, University Hospital Zurich, Zürich, Switzerland Purpose: To examine the frequency of computed tomography (CT)-guided biopsy sampling errors in chondrosarcomas, as well as the impact of these errors and the achieved surgical margins on local recurrence-free survival (LRFS) and disease-specific survival (DSS). Material and methods: A total of 68 consecutive patients treated for chondrosarcoma from 2000–2015 were retrospectively reviewed with a minimum follow-up duration of 2 years. Results: The primary location was at the extremities in 46 patients (67.6%) and at the axial skeleton in 22 patients (32.4%). Seven patients underwent planned intralesional curettage. Surgical margins were assessed in the remaining 53 patients and included 21 wide (39.6%), 25 marginal (47.1%), and seven intralesional (13.2%) resections. Biopsy sampling errors occurred in ten patients (14.7%). LRFS was 82.2±7.8% at 5 years and 76.9±7.8% at 10 years. An intact anatomical barrier was associated with the most preferable LRFS of 89±10.5% after 10 years. DSS was 79.2±8.5% at 5 years and 75.5±6.4% at 10 years. The metric distance of the surgical margin and the presence of a biopsy sampling error did not affect either LRFS or DSS. Conclusion: Even though histological grading in chondrosarcoma is difficult, sampling errors in preoperative biopsies are relatively rare and do not adversely affect outcomes. The presence of an anatomical barrier has a greater impact on LRFS than the metric distance of the surgical margins. Keywords: bone tumor, chondrosarcoma, survival, local recurrence, surgical margin, biopsy sampling error