LAUSR

OBJECTIVES As few large studies identify correlative biomarkers in chordoma, our objective was to use our large, single-center chordoma tumor bank to identify novel signaling pathways. METHODS Clinical and pathologic data for 73 patients with chordoma were retrospectively collected. Tumor microarrays were built from 61 archived chordoma specimens; immunohistochemistry for TOMM20, TIGAR, and MCT1 were performed; and semiquantitative analysis of staining intensity and percentage of positive tumor cells was performed. Average composite scores of MCT1, TIGAR, and TOMM20 expression were compared by disease status and anatomic location. RESULTS Higher expression of TOMM20 was seen in recurrent and metastatic chordomas compared with primary lesions. Comparing composite scores of primary lesions in patients with primary disease only vs those with recurrent disease showed that TIGAR and TOMM20 expressions are significantly higher in primary lesions, followed by a history of recurrence. A TOMM20 composite score of greater than or equal to 3 significantly decreased overall survival (hazard ratio [HR], 5.83) and recurrence-free survival (HR, 8.95). CONCLUSIONS Identifying novel signaling pathways that promote chordoma growth and recurrence is critical for developing targeted therapy for chordoma. TOMM20 may be a biomarker associated with chordoma disease progression.