Notably, the MGMT promoter contains 2 glucocorticoid receptor response elements, thus linking TMZ resistance to dexamethasone use.47 Other deleterious effects of dexamethasone on infection risk, lymphopenia, metabolic disturbances, thromboembolism risk, muscle wasting, and diminished performance status may also contribute to diminished survival.48,49 Nevertheless, in this cohort of patients, the deleterious impact of corticosteroid use by multivariate analysis was less than half of the impact of PPI use. This evidence concerns the gene NR3C1 and lymphopenia.