Abstract
BACKGROUND
Glioblastoma (GBM) is the most common primary malignant brain tumor and carries a very poor prognosis. Recent data report a negative association between the incidence of GBM and atopic disease. The underlying immunologic mechanisms of protection and the associated potential biomarkers are unclear. The aim of this retrospective study is to assess the relationship of eosinophil count to GBM risk by collecting eosinophil count in GBM patients with and without existing atopic disease.
METHODS
This is a retrospective study of 790 patients diagnosed with GBM from 2009–2019. Of those patients, 140 had laboratory values at least one year prior to diagnosis. Chart review was used to exclude patients with lymphoma, leukemia, other cancers, myelodysplastic syndromes, and unconfirmed drug, food, and adhesive reactions. 14 patients with chart-confirmed allergic rhinitis, asthma, or eczema and 47 controls were found. Wilcoxon rank sum test was used to compare the two groups.
RESULTS
The two groups did not differ in pre-diagnostic eosinophil counts (p=0.426). The two groups also did not differ in pre-diagnostic basophil, lymphocyte, neutrophil, or monocyte counts. Pre-diagnostic eosinophil to lymphocyte, monocyte to lymphocyte, and neutrophil to lymphocyte ratios also did not differ between the two groups. There were no other quantitative differences that would suggest a difference in immune cell profile.
CONCLUSIONS
In our study, the subset of GBM patients with atopic disease did not significantly differ in eosinophil count or other white blood cell subtypes when compared to GBM patients without atopic disease. Given that atopic disease is a known protective factor, and our atopic patients with GBM had normal eosinophil counts, we conclude that underlying immunologic factors such as eosinophilia may be protective from GBM as opposed to simply the presence of atopic disease. Prospective analysis to best understand eosinophil count as a surrogate for GBM risk is warranted.