Risk Factors Impacting Operative Mortality and Overall Survival in Adults Treated for Skull Base Chordoma and Chondrosarcoma

Purpose/Objective(s): To evaluate the impact of type of treatment center and access to care on mortality and survival in patients treated for skull base chordoma and chondrosarcoma.

Materials/Methods: We queried the National Cancer Database (NCDB) for patients over the age of 18 years with chondrosarcoma or chordoma of the skull base as defined by ICD-O-3 codes for histology and primary disease site. Of 1,241 skull base chordoma and chondrosarcoma patients, 1102 had available follow-up data (chordoma, 488; chondrosarcoma, 614 patients). Facilities were also stratified by volume into low-, medium-, and high-volume centers based on <10 cases, 10–20, and >20 cases, over the period of 2004 to 2014.

Results: Overall 30-day and 90-day mortality rates for the 925 patients who had surgery and available mortality data were 0.9 and 1.5%, respectively. On univariate analysis, only lower levels of education were associated with an increased risk of operative mortality. With a median follow-up 52 months (0.03–152 months), log-rank analysis demonstrated the following factors were associated with higher survival: metro size (p = 0.0294), academic center (p < 0.0001), age < median (p < 0.001), and having private insurance (p < 0.0001). Comparing across high-, medium-, and low-volume centers respectively: High-volume centers were most likely to be academic (63% vs. 57% and 41%), deliver radiotherapy (54% vs. 45% and 43%), escalate dose over 70Gy (37% vs. 10% and 7%), and utilize proton radiotherapy (29% vs. 8% and 4%).

Conclusion: While level of education was the only socioeconomic factor significant in univariate analysis of 30- or 90-day operative mortality for skull-base chordoma and chondrosarcoma, treatment and access to an academic facility, high-volume center including being from a metro area, younger age, and private insurance were associated with a statistically significant increase in overall survival.