The clinical impact of EGFR alterations in elderly glioblastoma patients: results from a real-life cohort.

Abstract

The incidence of glioblastoma in the elderly population is increasing as the worldwide population ages. The differential and poorer survival in the elderly population compared to younger patients is partially explained. The present study aimed to investigate the clinical impact of epidermal growth factor receptor EGFR-altered glioblastoma in a real-life elderly glioblastoma population. A bicentric and retrospective study was conducted. Patients were 70years or older and suffering from histomolecularly confirmed glioblastoma. Single nucleotide variants (SNV), amplification, or chromosome 7 polysomy were sought. The primary endpoint was the comparison of overall survival (OS) in patients with or without EGFR alteration. Secondary objectives were to determine other clinical parameters correlated with EGFR alteration status. Seventy-three patients were analyzed: 41.1% had at least one EGFR alteration. The presence of EGFR alteration did not impact overall survival: HR 0.97 [0.6-1.57], p = 0.9; the median overall survival was 6.5months [5.3-9.3] in the EGFR-altered group versus 7months [4.5-10] in the EGFR wild-type group, p = 0.75. In multivariate analysis, tumor resection was associated with a significant overall survival improvement: the median OS in the resected group (n = 20) was 11months [95% CI 7.8-22] versus a median OS of 5.5months [4.6-7.8] in the unresected group (n = 53), without correlation to EGFR alteration status. In the modern era of molecular characterization and improved treatment modalities, the presence of at least one EGFR alteration did not influence survival outcomes in an elderly population of glioblastoma patients.