(P 163) CHONDROSARCOMA IN THE AYA POPULATION

Objective: Chondrosarcoma is the second most common primary bone malignancy; however, its incidence is low in the adolescent and young adult (AYA) population. We sought to review our experience with patients between the ages of 15 and 39 years of age to evaluate their demographics, treatment and oncologic outcomes.

Methods: A retrospective review of the tumor registry at a comprehensive cancer center for AYA patients treated between 1997 to 2023 was performed. Demographics, oncologic information and treatment variables were evaluated. Primary outcome evaluated was overall survival.

Results: Out of 941 patients with a bone sarcoma, 42 had the diagnosis of chondrosarcoma. 56% were male and 84.1% were white. Mean age at diagnosis was 30.5 years (range 17-39). The majority were in the pelvis 16 (39%), followed by long bones 12 (29.2%). Three had the diagnosis of multiple hereditary exostoses. 87.8% were conventional chondrosarcoma, 4.8% juxtacortical, 4.8% dedifferentiated and 2.4% myxoid chondrosarcoma. 83% were intermediate and high-grade tumors. 8 (19%) presented with stage 4 disease. Forty (95%) patients underwent surgery for either primary resection or metastasectomy. For the 34 patients who presented with localized disease and underwent surgery, 91% had a resection, with 9 (26%) having surgery for a local recurrence, 1 (2.9%) had an amputation and 2 (6%) had an intralesional curetting. 14 (34%) of the cohort received radiation, most were either face/ skull or pelvis and one in a patient with stage 4 disease. Four (9.7%) patients received chemotherapy. Overall survival was 71%, mean survival was 140 months (range 4-599) from initial diagnosis. For the 22 patients with localized grade 2 and 3 disease, the overall survival was 63%, with mean survival of 140 months (range 22-505) from initial diagnosis. Overall survival of patients with metastatic disease was 43%, mean survival was 40.2 months.

Conclusion: Chondrosarcoma is not common in the adolescent and young adult population. The overall survival is comparable to reported survival in all patients. The distribution of site, age, gender and stage at presentation were also similar to the adult population. Further analysis of margin status, use of adjuvant therapies and management of metastatic disease is warranted.