There is a high chance of glioma recurring even after successful treatment. Patients initially diagnosed with low grade glioma may survive several years after treatment but may eventually progress to a high-grade glioma.
Few possible reasons for recurrence are:
During surgery, the astrocytes that surrounds and being the support of nerve cells are injured and this promotes the proliferation and migration of tumor.
Due to the complexity of the brain structure, the cancer cells might not be 100% removed, even after surgery, therefore, it could lead to the recurrence of cancer.
Since most of the residual cancer cells are located in the resection margin, it may seem relevant that tumor would occur in this area.