====== Glioma recurrence ======

see also [[Glioblastoma recurrence]]

[[Glioma]] [[recurrence]] is a significant clinical challenge in [[neuro-oncology]]. The [[recurrence]] [[rate]] depends on multiple factors, including the tumor's grade, molecular characteristics, and initial treatment response. Here are some key aspects of glioma recurrence:

===== 1. Risk Factors for Recurrence =====

Tumor Grade: High-grade gliomas (e.g., glioblastoma, WHO grade 4) have a higher recurrence rate than low-grade gliomas.
Extent of Resection: Incomplete surgical removal leads to a higher risk of recurrence.
Molecular Markers:
IDH wild-type gliomas tend to be more aggressive.
MGMT promoter methylation is associated with better response to temozolomide (TMZ).
TERT promoter mutations and EGFR amplification are linked to poor prognosis.
Location: Tumors in eloquent areas may be less resectable, leading to residual disease and recurrence.
Therapeutic Response: Resistance to radiotherapy and chemotherapy contributes to recurrence.
===== 2. Patterns of Recurrence =====

Local recurrence is the most common pattern, occurring within 2 cm of the original tumor site.
Distant recurrence may occur due to migratory tumor cells or treatment-induced changes.
Leptomeningeal spread is rare but seen in aggressive cases.
===== 3. Diagnostic Workup for Recurrence =====

MRI with contrast: T1-weighted imaging with gadolinium contrast is the standard for detecting recurrence.

MR Spectroscopy (MRS): Helps differentiate recurrence from radiation necrosis.

PET Imaging (e.g., FDG-PET, amino acid PET): Can assist in distinguishing viable tumor tissue from treatment effects.

[[Liquid biopsy]] ([[circulating tumor DNA]], cfRNA): Emerging tool for non-invasive monitoring.
===== 4. Treatment Options for Recurrent Gliomas =====

Repeat Surgery: Considered in select cases, particularly if mass effect is present.
Re-irradiation: Stereotactic radiosurgery (SRS) or fractionated radiation may be used cautiously.
Chemotherapy:
Temozolomide (TMZ) rechallenge (if MGMT methylated and prior response was good).
Bevacizumab (Avastin): Anti-VEGF therapy for edema control and symptom relief.
Lomustine (CCNU), procarbazine, vincristine (PCV regimen): Used in some recurrent cases.
Targeted and Experimental Therapies:
TTFields (Tumor Treating Fields): Device-based therapy for recurrent glioblastoma.
Immunotherapy (e.g., checkpoint inhibitors, vaccines): Limited success but ongoing research.
CAR-T therapy and oncolytic viruses: Under investigation.
===== 5. Prognosis and Survival =====

[[Recurrent glioblastoma]] has a poor prognosis, with median survival of 6–9 months after recurrence.
Low-grade gliomas have better outcomes but may transform into higher-grade tumors over time.

----


[[MicroRNA]]s (miRs) act as [[oncogene]]s or tumor-suppressor genes and regulate the [[proliferation]], [[apoptosis]], [[invasion]], differentiation, [[angiogenesis]], and behavior of [[glioma stem cell]]s, which are important in [[glioma]] [[recurrence]] and development.