Patient, Disease, and Treatment-Related Factors Affecting Progression-Free and Disease-Specific Survival in Recurrent Chondrosarcomas of the Skull Base.

Background: Recurrent skull base chondrosarcomas (CSA) are difficult to treat, and limited data are available to help guide subsequent therapy.
Objective: To further characterize the natural history of CSA and identify treatment modalities that were most effective in prolonging progression-free (PFS) and disease-specific survival (DSS).
Methods: We conducted a single-institution retrospective review of patients with recurrent skull base CSA from 1993 to 2021. Kaplan-Meier survival analyses for PFS and DSS were completed. Univariable and multivariable Cox proportional hazards regression models were used to identify patient-related, treatment-related, and disease-related factors that predicted PFS and DSS.
Results: A total of 28 patients and 84 episodes of recurrence were included. One-year PFS was 70.6%, 5-year PFS was 28.9%, and 10-year DSS was 78.5%. The median time to first progression was 23.9 months (range, 2.8-282 months). In univariable Cox proportional hazards regression, male sex, higher grade histology, fourth or greater progression episode status, distal pattern of recurrence, and treatment of recurrence without surgery or with chemotherapy alone predicted worse PFS. Multivariable regression predicted shortened DSS in male patients (hazard ratio [HR] 0.16; P = .021) and higher-grade tumors (HR 0.22; P = .039). Treatment of recurrence with surgery was associated with, but did not significantly predict, improved DSS (HR 1.78; P = .11).
Conclusion: Several patient and disease-specific factors were associated with shorter PFS and DSS in recurrent skull base chondrosarcoma. For recurrences amenable to resection, surgery is recommended for treatment of recurrent CSA. Local recurrence management without surgery results in shorter PFS and DSS.
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