Comprehensive Analysis Reveals Epithelial Growth Factor Receptor as a Potential Diagnostic Biomarker in Glioblastoma Multiforme.

Glioblastoma multiforme (GBM), a highly aggressive tumor of the central nervous system, is the most common malignant brain tumor and poses a significant risk to life. GBM patients have a low survival rate owing to their aggressive nature, poor prognosis, genomic variations among patients, and histopathological differences. In this study, we used several bioinformatics platforms, namely Tumor Immune Estimation Resource (TIMER), Gene Expression Profiling Interactive Analysis (GEPIA), University of Alabama at Birmingham Cancer Data Analysis Portal (UALCAN) databases, Kaplan-Meier plotter, and cBioPortal, to conduct a comprehensive analysis to highlight the expression of epithelial growth factor receptor (EGFR) in patients with GBM. Our study highlights EGFR as a potential diagnostic and prognostic marker. According to the TIMER database, EGFR was upregulated in five cancers, including GBM, head and neck squamous cell carcinoma, kidney renal cell carcinoma, kidney renal cell papillary cell carcinoma, and lung squamous cell carcinoma, whereas it was downregulated in breast invasive carcinoma, colon adenocarcinoma, pheochromocytoma and paraganglioma, prostate adenocarcinoma, rectum adenocarcinoma, and uterine corpus endometrial carcinoma. Our investigation highlighted the expression of EGFR in various clinicopathological parameters, which include age, sex, gender, and TP53 mutation status in patients with GBM. We found that EGFR was upregulated in middle-aged and older adults compared to normal tissues, while it was not significantly downregulated in young adults and older adults. EGFR was upregulated in Caucasians compared to normal tissue, whereas it was downregulated in Asian and African American populations, but this was not statistically significant. In terms of gender, EGFR was upregulated in the male population compared to the female population. Furthermore, EGFR was upregulated in patients with TP53 mutations compared to normal tissues. We also examined the correlation between EGFR gene expression and immune cell infiltration in GBM patients and the impact of EGFR mutations on patient prognosis. Our results revealed a significant positive correlation between EGFR, B cells, and macrophages, but this was not significant for other cell types. This study signified that upregulation of EGFR was associated with a poor prognosis in patients with GBM validated by the GEPIA and UALCAN databases.