Racial/ethnic disparities in treatment pattern and time to treatment for adults with glioblastoma in the US.

Purpose Race/ethnicity have been previously shown to significantly affect survival after diagnosis with glioblastoma, but the cause of this survival difference is not known. The aim of this study was to examine variation in treatment pattern and time to treatment by race/ethnicity, and the extent to which this affects survival. Methods Data were obtained from the National Cancer Database (NCDB) for adults ≥ 40 with glioblastoma from 2004 to 2016 (N = 68,979). Treatment patterns and time to treatment by race/ethnicity were compared using univariable and multivariable logistic and linear regression models, respectively, and adjusted for known prognostic factors and factors potentially affecting health care access. Results Black non-Hispanics (BNH) and Hispanics were less likely to receive radiation and less likely to receive chemotherapy as compared to White non-Hispanics (WNH). Time to radiation initiation was ~ 2 days longer and time to chemotherapy initiation was ~ 4 days longer in both groups in comparison to WNH. Conclusion Both race/ethnicity and treatment timing significantly affected survival time, and this association remained after adjustment for known prognostic factors. Additional research is necessary to disentangle the specific causal factors, and the mechanism with which they affect survival.