Molecular Characteristic of High Grade Glioma in Relation to 5-ala Fluorescence Intensity

Abstract The intensity of 5-ALA fluorescence used in glioma surgery varies within tumors, and among different patients, several molecular and external factors have been implicated; however, there is no clear evidence analysing the difference in fluorescence according to glioma molecular characteristics. This study aimed to compare the molecular factors of glioma samples with fluorescence intensity to identify potential cofounders and associations with clinically relevant tumor features. Tumor samples from high-grade glioma patients treated with 5-ALA for guided resection were included for comparative analysis of fluorescence intensity and molecular features. The mean fluorescence was compared for each molecular variation. p53, ATRX and Ki67 expression and IDH1 mutation status were assessed via immunohistochemistry. The patients were followed upfor progression-free survival and overall survival. We found that the fluorescence intensity for each specific tumor was independent of the methylation status of the MGMT promoter region, as assessed by pyrosequencing, and that there was no association between fluorescence and p53, ATRX, or IDH1 mutation, as assessed by immunochemistry. Additionally, fluorescence intensity was not related to the duration of tumor recurrence or overall survival. Weargue that many factors are involved in the difference in fluorescence intensity and may be related to the specific metabolic status of the glioma cells analysed, which is likely responsible for the variation in fluorescence.