Survival in Mesenchymal Chondrosarcoma Varies Based on Age and Tumor Location: A Survival Analysis of the SEER Database.

BACKGROUND: Studies suggest that mesenchymal chondrosarcoma is associated with a poorer prognosis and a higher proportion of extraskeletal tumors than conventional chondrosarcoma. However, these investigations have been small heterogeneous cohorts, limiting analysis of prognostic factors. QUESTIONS/PURPOSES: (1) What is the 5- and 10-year survival rate of patients diagnosed with mesenchymal chondrosarcoma? (2) What is the effect of demographic and tumor characteristics on survival in patients with mesenchymal chondrosarcoma? METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all patients diagnosed with mesenchymal chondrosarcoma from 1973 to 2011. SEER reports survival data on over 8.2 million patients with cancer and has attained 98% completeness in reporting. Using variables within the database, this study designated each patient's tumor as skeletal or extraskeletal and cranial, axial, or appendicular, respectively. Overall survival (OS) was determined for the entire series as well as each group. Median survival was calculated using Kaplan-Meier methods. Cox proportional hazards regression was used to determine whether demographic and tumor variables affected survival. Two hundred five patients with mesenchymal chondrosarcoma were identified, including 82 (40%) skeletal and 123 (60%) extraskeletal. RESULTS: OS for the entire series was 51% (95% confidence interval [CI], 43%-58%) and 43% (95% CI, 35%-51%) at 5 and 10 years, respectively. No difference in OS was detected between extraskeletal and skeletal tumors. Kaplan-Meier analyses showed OS was worse for tumors in axial locations compared with appendicular and cranial locations. Appendicular tumors demonstrated an OS of 50% (95% CI, 36%-63%) at 5 years and 39% (95% CI, 26%-52%) at 10 years. OS for axial tumors was 37% (95% CI, 25%-49%) and 31% (95% CI, 20%-43%), whereas it was 74% (95% CI, 59%-84%) and 67% (95% CI, 50%-79%) for cranial tumors at 5 and 10 years, respectively. When controlling for age, sex, tumor origin, and tumor location, the presence of metastasis (hazard ratio [HR], 12.38; 95% CI, 5.75-26.65; p < 0.001) and 1-cm size increase (HR, 1.16; 95% CI, 1.09-1.23; p < 0.001) were both independently associated with an increased risk of death. Tumor location showed different behaviors depending on patient age. In comparison to cranial tumors at age 20 years, the HR was 5.56 (95% CI, 1.47-21.05; p = 0.01) for axial tumors and 6.26 (95% CI, 1.54-25.42; p = 0.01) for appendicular tumors. At age 60 years, those ratios were 0.10 (95% CI, 0.02-0.55; p = 0.01) and 0.14 (95% CI, 0.04-0.58; p = 0.01), respectively. CONCLUSIONS: Our data suggest that extraskeletal tumors are more common than previously reported; however, this factor does not have clear prognostic value. Presence of metastatic disease and increased tumor size are the main predictors of poor survival outcome. Cranial tumors appear to have a different clinical behavior with our data suggesting better overall survival in young patients (compared with axial and appendicular locations) and a worse survival outcome in older patients. LEVEL OF EVIDENCE: Level IV, prognostic study.

Mesenchymal chondrosarcoma: prognostic factors and outcome in 113 patients. A European Musculoskeletal Oncology Society study.

BACKGROUND: Mesenchymal chondrosarcoma (MCS) is a distinct, very rare sarcoma with little evidence supporting treatment recommendations. PATIENTS AND METHODS: Specialist centres collaborated to report prognostic factors and outcome for 113 patients. RESULTS: Median age was 30 years (range: 11-80), male/female ratio 1.1. Primary sites were extremities (40%), trunk (47%) and head and neck (13%), 41 arising primarily in soft tissue. Seventeen patients had metastases at diagnosis. Mean follow-up was 14.9 years (range: 1-34), median overall survival (OS) 17 years (95% confidence interval (CI): 10.3-28.6). Ninety-five of 96 patients with localised disease underwent surgery, 54 additionally received combination chemotherapy. Sixty-five of 95 patients are alive and 45 progression-free (5 local recurrence, 34 distant metastases, 11 combined). Median progression-free survival (PFS) and OS were 7 (95% CI: 3.03-10.96) and 20 (95% CI: 12.63-27.36) years respectively. Chemotherapy administration in patients with localised disease was associated with reduced risk of recurrence (P=0.046; hazard ratio (HR)=0.482 95% CI: 0.213-0.996) and death (P=0.004; HR=0.445 95% CI: 0.256-0.774). Clear resection margins predicted less frequent local recurrence (2% versus 27%; P=0.002). Primary site and origin did not influence survival. The absence of metastases at diagnosis was associated with a significantly better outcome (P<0.0001). Data on radiotherapy indications, dose and fractionation were insufficiently complete, to allow comment of its impact on outcomes. Median OS for patients with metastases at presentation was 3 years (95% CI: 0-4.25). CONCLUSIONS: Prognosis in MCS varies considerably. Metastatic disease at diagnosis has the strongest impact on survival. Complete resection and adjuvant chemotherapy should be considered as standard of care for localised disease.