Multimodality Treatment of Skull Base Chondrosarcomas: The Role of Histology Specific Treatment Protocols

• Published in: Neurosurgery Vol. 81; no. 3; pp. 520 - 530
• Main Authors: Raza, Shaan M., Gidley, Paul W., Meis, Jeanne M., Grosshans, David R., Bell, Diana, DeMonte, Franco
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.09.2017; Copyright by the Congress of Neurological Surgeons; Wolters Kluwer Health, Inc
• Subjects: Chemotherapy; Chondrosarcoma - epidemiology; Chondrosarcoma - pathology; Chondrosarcoma - therapy; Combined Modality Therapy - methods; Combined Modality Therapy - statistics & numerical data; Disease-Free Survival; Histology; Humans; Radiation therapy; Retrospective Studies; Skull; Skull Base Neoplasms - epidemiology; Skull Base Neoplasms - pathology; Skull Base Neoplasms - therapy; Surgery; Radiation Therapy; Chondrosarcoma; Chemotherapy; Sarcoma; Skull Base; Surgery; Oncology; Malignancy
• ISSN: 0148-396X; 1524-4040
• DOI: 10.1093/neuros/nyx042

Abstract BACKGROUND: Limited data exist to guide the multimodality management of chondrosarcomas (CSAs) arising in the skull base. OBJECTIVE: To determine the impact of histological subtype/grade on progression-free survival (PFS) and the indications for surgery, radiation, and chemotherapy based on histology. METHODS: A retrospective review was performed of 37 patients (conventional type: 81%, mesenchymal: 16.2%, dedifferentiated: 2.7%) treated at The University of Texas M.D. Anderson Cancer Center. Of the conventional subtype, 23% were grade 1, 63% were grade 2, and 14% were grade 3. In addition to surgery, mesenchymal/dedifferentiated CSAs (18% of the cohort) underwent neoadjuvant chemotherapy and 48.6% of the overall cohort received adjuvant radiotherapy. Histological grade/subtype and treatment factors were assessed for impact on median PFS (primary outcome). RESULTS: Conventional subtype vs mesenchymal/dedifferentiated was positively associated with median PFS (166 vs 24 months, P < .05). Increasing conventional grade inversely correlated with median PFS (P < .05). Gross total resection positively impacted PFS in conventional CSAs (111.8 vs 42.9 months, P = .201) and mesenchymal/dedifferentiated CSAs (58.2 vs 1.0 month, P < .05). Adjuvant radiotherapy significantly impacted PFS in conventional grades 2 and 3 (182 vs 79 months, P < .05) and a positive trend with mesenchymal/dedifferentiated CSAs (43.5 vs 22.0 months). Chemotherapy improved PFS for mesenchymal/dedifferentiated CSAs (50 vs 9 months, P = .089). CONCLUSION: There is a potential need for histological subtype/grade specific treatment protocols. For conventional CSAs, surgery alone provides optimal results grade 1 CSAs, while resection with adjuvant radiotherapy yields the best outcome for grade 2 and 3 CSAs. Improvements in PFS seen with neoadjuvant therapy in mesenchymal/dedifferentiated CSAs indicate a potential role for systemic therapies. Larger studies are necessary to confirm the proposed treatment protocols.