Skull Base Chordoma: Long-Term Observation and Evaluation of Prognostic Factors after Surgical Resection

Background: Skull base chordoma (SBC) is relatively rare and data on its clinical outcome after surgical resection and adjuvant radiotherapy are still limited. Objective: Analyzing the clinical postoperative outcome of SBC patients and defining prognostic factors regarding current treatment modalities. Methods and Material: In this study, 41 SBC patients from 2001 to 2017 were retrospectively analyzed in this single-center study. Results: The most common clinical symptoms were headache (63%) and problems concerning vision (54%) like diplopia. The follow-up controls took place from 1 to 192 months. The mean survival time for the patients was 123.37 months (95% CI 90.89u155.86). The 5- and 10-year survival rates were 73.3 and 49%, respectively. Regarding the Karnofsky-Performance Scale (KPS), Cox regression showed a significant relationship between the survival rates in the overall study population and pre-surgery KPS (P = 0.004). This was further supported with a positive significant correlation between the pre-surgery KPS and the KPS at the last follow-up (P = 0.039). Conclusion: Statistical analysis showed that repeat surgical resection and radiotherapy could be prognostic factors. Furthermore, we were able to show that mortality decreased by 4.5% with each 10 points increase of pre-surgery KPS. This could be a major prognostic factor when deciding treatment modalities. Nevertheless, further standardized clinical studies with a larger patient population should be carried out to extrapolate prognostic factors and improve treatment modalities.