Background
Molecular factors influence relapse patterns in glioblastoma. The hotspot mutation located at position 289 of the extracellular domain of the epidermal growth factor receptor (EGFRA289mut) is associated with a more infiltrative phenotype. The primary
Conclusion
We highlighted a link between the EGFRA289 mutation and the relapse pattern in glioblastoma. The independent role of EGFRA289mut and its clinical implication should now be explored in further studies.
Methods
An ancillary study from a prospective cohort of patients suffering from glioblastoma was conducted. All patients received radiotherapy and concomitant temozolomide. The population was divided into two groups according to EGFRA289 status (mutated versus wild-type). The primary endpoint was the overlap score (varying from 0 to 1) between the initial irradiated tumor volume (Vinit) and the relapse volume (Vr). Secondary endpoints explored the impact of EGFRA289mut on survival.
Results
One hundred twenty-eight patients were included and analyzed: 11% had EGFRA289mut glioblastoma (n = 14/128). EGFRA289mut glioblastomas had a relapse pattern that was more marginal than EGFRA289wt glioblastomas: a median overlap score Vinit/Vr of 0.96 was observed in the EGFRA289mut group versus 1 in the EGFRA289wt group (P = 0.05). Half of the population with EGFRA289mut tumor (n = 7/14) had a marginal relapse (i.e. overlap scoreVr/Vinit ≤ 0.95) compared to 23.7% (n = 27/114) in the EGFRA289wt group, P = 0.035. EGFRA289mut did not influence survival.