Chordoma of the Skull Base: A National Cancer Database Analysis of Current Practice Patterns and Outcomes

Introduction: Chordomas of the skull base are aggressive, locally destructive tumors that arise from the remnants of the fetal notochord. Current guidelines recommend maximal safe surgical resection followed by adjuvant radiation therapy. However, owing to the rarity of these tumors, the optimal radiotherapeutic regimen with regards to dose and modality is unclear.

Methods: The National Cancer Database (NCDB) was queried from 2004 to 2016. Data from adult patients were extracted, including tumor characteristics, comorbidity indices, and details of treatment (surgery, radiation, and chemotherapy). Radiotherapy was evaluated both with regards to modality (traditional, proton-beam) as well as overall dose. Subgroup analyses examined the effect of radiotherapy on varying degrees of surgical resection. The primary outcome of interest was overall survival (OS), which was evaluated for specific treatment cohorts using Cox univariate and multivariate regression constructs along with associated survival curves.

Results: We identified 798 patients with a diagnosis of skull base chordoma. Mean OS in this cohort was 9.57 years. A majority of patients received surgical resection (89.1%), with 53.9% receiving radiotherapy and 6.5% receiving chemotherapy. After adjusting for baseline characteristics using multivariate regression, advanced age and increased tumor size were associated with decreased OS. Surgical resection was associated with increased OS, while neither radiotherapy nor chemotherapy was associated with OS. However, in patients that did receive radiation, dosage > 6,000 cGy was associated with increased OS (HR: 0.51; p = 0.038); OS did not vary significantly between traditional and proton-based methods.

Conclusions: Our multi-institutional analysis supports the use of partial and radical surgical resection to improve survival in patients with skull base chordomas. Among patients who receive radiotherapy, higher radiation dose is associated with improved survival.

Publikationsverlauf

Artikel online veröffentlicht:
01. Februar 2023