Low-grade Gliomas

What are Low-grade Gliomas?

Low-grade gliomas (LGGs) are slow-growing primary brain tumours that arise from glial cells, which provide structural and functional support to the nervous system. These tumours are typically classified as World Health Organisation (WHO) Grade 2 and are more commonly diagnosed in younger adults compared to high-grade malignant brain tumours. Although low-grade gliomas tend to grow more slowly, they can still significantly impact neurological function and may progress to more aggressive forms over time.

Types of Low-grade Gliomas

The 2 main subtypes of Low Grade Glioma are:

Astrocytomas
Oligodendrogliomas

Symptoms of Low-grade Gliomas

The common symptoms of low-grade gliomas vary depending on tumour size, growth rate, and location within the brain.

Neurological Symptoms:

Persistent headaches
Seizures (often the first presenting symptom)
Cognitive or behavioural changes
Memory difficulties
Speech disturbances
Motor weakness or coordination problems
Visual disturbances

General Symptoms:

Nausea or vomiting
Fatigue
Increased intracranial pressure in advanced cases

Risk Factors of Low-grade Gliomas

Although exact causes are not always clear, contributing factors may include:

Genetic predisposition
Prior radiation exposure
Certain hereditary syndromes
Family history of brain tumours

Diagnosis of Low-grade Gliomas

Diagnosis of low-grade gliomas involves detailed neurological and radiological assessment including:

MRI brain with contrast (gold standard)
Biopsy for histopathological confirmation
Molecular testing (e.g., IDH mutation, 1p/19q codeletion)

Treatment of Low-grade Gliomas

Management of low-grade gliomas depends on tumour type, size, location, and the patient’s health status.

Surgical resection: Preferred initial treatment when feasible
Active surveillance: In select cases of slow-growing, asymptomatic tumour
Targeted therapy: Vorasidenib (IDH inhibitor)
Radiation therapy: For residual or progressive disease
Chemotherapy: Commonly temozolomide or PCV regimen is recommended

Prognosis of Low-grade Gliomas

Low-grade gliomas generally have a better prognosis than high-grade gliomas, but outcomes vary based on molecular profile, age, and extent of the tumour and surgical removal. Long-term follow-up is essential, as recurrence or malignant transformation can occur.