Base of skull chordoma. A correlative study of histologic and clinical features of 62 cases.

BACKGROUND: Chordomas are uncommon primary malignant tumors of bone that typically occur in the axial skeleton including the sacrum, vertebrae, and skull base. The base of skull tumors usually are not amenable to complete surgical resection, and most require postoperative radiotherapy. The natural history of skull base chordoma is typified by slow locally invasive tumor progression and eventual death, although few parameters are known that allow stratification of patients into prognostic groups.

METHODS: Sixty-two patients with skull base chordomas treated at the Massachusetts General Hospital by proton beam irradiation therapy with at least 2 years of follow-up information were reviewed in an attempt to identify clinical and pathologic parameters that predicted outcome.

RESULTS: Female sex, tumor necrosis in preradiation treatment biopsy, and tumor volume in excess of 70 ml were each independent predictors of shortened overall survival after radiation therapy for skull base chordoma.

CONCLUSIONS: Stratification of patients with skull base chordoma into poor and good outcome groups can be performed using the three parameters identified in our study. In addition, the striking difference in survival between the sexes suggests that further investigations of these tumors should include determination of their hormonal receptors status and consideration of hormonal manipulation in their management.