Skull base surgery for malignant tumors: The 2nd international collaborative study (1995-2015)

Background: The current study presents the effort of a global collaborative group to review the management and outcomes of malignant tumors of the skull base worldwide. Patients and methods: A total of 28 institutions contributed data on 3061 patients. Analysis evaluated clinical variables, survival outcomes, and multivariable factors associated with outcomes. Results: The median age was 56 years (IQR 44-67). The open surgical approach was used in 55% (n = 1680) of cases, endoscopic resection was performed in 36% (n = 1087), and the combined approach in 9.6% (n = 294). With a median follow-up of 7.1 years, the 5-year OS DSS and RFS were 65%, 71.7% and 53%, respectively. On multivariable analysis, older age, comorbidities, histology, dural/intracranial involvement, positive margins, advanced stage, and primary site were independent prognostic factors for OS, DSS, and RFS. Adjuvant RT was a protective prognostic factor. Conclusion: The progress across various disciplines may have contributed to improved OS and DSS in this study compared to previous reports.