Page 46 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

Chapter 2
curettage has been associated with unacceptably high recurrence rates in previous series on pelvic chondrosarcoma5, 31. Many authors therefore have recommended resection with clear margins for pelvic chondrosarcoma of any grade1, 4-6. As long as it is not possible to reliably distinguish between grade 1 and higher-grade lesions preoperatively, we concur with previous authors stating that en bloc resection is the preferable treatment option for pelvic chondrosarcoma5, 31.
Tumor grade was also found to be associated with the risk of tumor recurrence. Previous studies showed con icting results with regard to chondrosarcoma grade and recurrence rates19, 23. Ninety- ve percent of the recurrences occurred within in the rst ve years after the surgical procedure. Therefore, we recommend close follow-up with an annual MRI scan during the rst postoperative years ( gure 6), although the utility and accuracy of MRI scans may be hampered by the presence of metallic implants. Alternatively, a CT-scan or uorine-18 uorodeoxyglucose positron emission tomography (FDG PET) imaging can be obtained, although less aggressive lesions may not be avid on PET34.
Although survival rates after marginal and intralesional resection were nearly identical, wide resection margins were associated with a signi cant survival advantage. Although wide margins do not eliminate the possibility of recurrent disease19, 25, 28, margins were the only treatment-related prognostic factor. After diagnosis of local relapse, the median survival was 2.4 years for grade 2 tumors, and 1.3 years for grade 3 tumors. These poor survival rates, combined with the association between margins and the risk of recurrence and disease-related death, underline the importance of obtaining wide margins during primary resection.
Tumor size was the third most important prognostic factor in our multivariable model; for each centimeter of increase in maximal tumor size, the risk of disease- related death increased by 8%. Others also found an in uence of chondrosarcoma size or volume on oncological outcome, but only performed univariable analyses24, 35, 36. One study identi ed a weak in uence only on the risk of local recurrence, not survival or metastasis, in multivariable analyses23. The presence of soft-tissue in ltration signi cantly in uenced progression-free survival, but failed to reach signi cance in our analyses on disease-related death. In contrast to our results, Fiorenza et al previously reported an in uence of soft-tissue in ltration on survival, but not local recurrence, for chondrosarcomas of the axial and appendicular skeleton23. In contrast with an earlier study24, the prognostic signi cance of soft tissue in ltration and tumor size in our study suggest that both the Enneking system and the AJCC classi cation appear to be reasonable
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