Targeted Genomic Sequencing Reveals Different Evolutionary Patterns Between Locally and Distally Recurrent Glioblastomas.

Background/Aim: Glioblastoma is the most malignant form of astrocytoma. The purpose of this study was to analyze the genetic characteristics of primary and recurrent glioblastomas using targeted sequencing and investigate the differences in mutational profiles between the locations of tumor recurrence. Materials and Methods: Fourteen glioblastoma patients who developed local (n=10) or distal (n=4) recurrence were included in the study. Targeted sequencing analysis was performed using the primary (n=14) and corresponding recurrent (n=14) tumor tissue samples. Results: The local and distal recurrence groups showed different genetic evolutionary patterns. Most of the locally recurrent glioblastomas demonstrated concordant mutational profiles between the primary and recurrent tumors, suggesting a linear evolution. In contrast, all cases of distally recurrent glioblastomas showed changes in mutational profiles with newly acquired mutations when compared to the corresponding primary tumors, suggesting a branching evolution. Conclusion: Locally and distally recurrent glioblastomas exhibit different evolutionary patterns.