Chondrosarcoma: The OSU experience

e23505 Background: Chondrosarcomas (CSC) constitute a diverse group of malignant bone tumors whose optimal management remains controversial, and patients with advanced disease have a dismal prognosis. Methods: Patients evaluated at The Ohio State University between January 1, 2010, to March 7, 2022, were included in the analysis. Data includes demographics, pathology, next-generation sequencing results, treatment combinations and responses, survival, time to progression, and recurrence. Results: 147 patients were eligible for this retrospective study. 29 patients were censored as they received no treatment or were lost to follow-up, leaving 118 evaluable patients. 83 patients had Conventional CSC, 16 had Dedifferentiated CSC, 4 Mesenchymal/Clear cell CSC, and 15 Myxoid/Extraskeletal myxoid CSC. 108 of 118 were white (91.5%), and 60 of 118 were male (50.8%). The median age at diagnosis was 57, ranging from 21-84 years old. 107 (92.2%) patients in the dataset had localized disease (Stage 1 or 2) and had curative treatment intent. The median tumor size was 6.3 cm for all patients. The most common site of the tumor was in the lower extremities (36.4%), followed by thoracoabdominal in 46 patients (38.9%), skull base/head and Neck in 17 patients (14.4%), and upper extremities in 12 of 118 (10.2%). The Median survival time differed significantly by subtype: Conventional CSC 104.6 months, dedifferentiated CSC 25.9 months, mesenchymal + clear cell CSC 57.2 months, myxoid or extraskeletal myxoid CSC 108.3 months, Overall survival in the entire cohort was 90.6 months. Overall comparison among subtypes Chi-square 57.41, ( p = 0.0). No association was seen between anatomic subsite and overall survival (upper extremities 202.80 months, lower extremities 85.30 months, and Pelvis & Retroperitoneal & lower back & Chest/Abdomen Wall/Upper Back 82.3 months, p = 0.216). The grade was associated with overall survival: grade 1 median 202.80 months, grade II 80.87 months, and grade III 21.067 months (p = 0.000). 18 patients received chemotherapy, 116 received surgery, and 12 received radiation. Among the 18 patients that received chemotherapy ( 4 patients had localized disease and 14 had the metastatic disease), the most used systemic therapy was Pazopanib 10/18 (55%), which had the longest time to progression of 22.42 months. The median time to progression of the 18 patients that received chemotherapy was 9.71 months. Conclusions: CSC remains a clinical challenge due to its rarity and limited treatment options. While surgical resection remains the mainstay of treatment for localized disease, systemic therapy and radiation can have important roles in selected subsets of patients. Further refinement of these care paradigms will require a multi-institutional/consortium effort to create a data repository and develop clinical trials to improve outcomes for these patients.