Prognostic Biomarkers in Spinal Chordoma: A Systematic Review

To the Editor: We read with great interest the recent article by Tauziede-Espariat et al (1) on prognostic and therapeutic markers in chordomas. The authors performed a retrospective multicentric study of 287 chordomas from 111 patients and attempted to correlate clinical, histopathologic, and immunohistochemical parameters with chordoma prognosis. They found that the extent of resection, tumor grade, and proton therapy were independent prognostic factors of progression-free survival, whereas the extent of resection, tumor location, and grade were independent predictors of overall survival in the patients on multivariate analysis. We commend the authors for performing the largest study in the literature on chordomas; the disease is rare, and previously published studies investigating prognostic factors of chordoma were limited to a small number of patients. Currently, the Frankel score is widely used to evaluate neurological status (2). However, we noted that the authors did not find tumor location in the upper cervical spine (including the C1 and C2 vertebrae) or worse preoperative Frankel score to be an independent predictor, which contradicts results from previous studies (3–6). Recently, many biomarkers have been …