fbpx

Astrocytoma

Updated : April 17, 2024





Background

Primary brain tumors, which include astrocytomas, are a collection of disorders that make up the most frequent solid tumors in children. Astrocytoma is cancer that starts in astrocytes, star-shaped glial cells in the cerebrum.

Gliomas are believed to develop from glial progenitor cells found in the brain and spinal cord. Glial tumors are the most common type of brain tumor, accounting for a 60percent of all cases.

Epidemiology

Glioma incidence was 4.7 per 100,000 person-years when age was considered.

Mortality/Morbidity

The following are typical survival ranges:

  • More than 10 years with WHO grade I (pilocytic astrocytoma)
  • More than 5 years with WHO grade II (low-grade diffuse astrocytoma)
  • Approximately 2 to 5 years for WHO grade III (anaplastic astrocytoma)
  • Glioblastomas (WHO grade IV) – 1 year

Gender

In pilocytic astrocytomas, there is no gender bias. In low-grade astrocytomas, there is a male to female ratio of 1.18:1.

Age

Pilocytic astrocytomas are more common in the first two decades of life. Lowgrade astrocytomas, which account for around one-fourth of adult cases, are more common in the 30-40 age group.

The following shows the distribution of low-grade astrocytomas:

  • 60 percent of the population is between the ages of 20 and 45
  • 30 percent of the population is over 45 years old
  • 10 percent of the population has been alive for less than 20 years
  • The average age of anaplastic astrocytoma is roughly 40 years.

Race

There were just minor racial differences discovered.

Anatomy

Pathophysiology

Multiple pathways contribute to astrocytoma’s profound influence. Direct penetration and oxygen depletion result in hypoxic damage to the normal brain parenchyma.

In addition, reactive oxygen species, neurotransmitters, and inflammatory cytokines all contribute to the disruption of homeostasis. The tumor’s bulk effect is also to blame for the varied clinical indications and symptoms.

Etiology

Most primary brain tumors have no known underlying etiology, with ionizing radiation exposure being the only known risk factor. There is no evidence of a link with other risks such as exposure to electromagnetic elements (cell phones), brain injury, or occupational risk factors.

A small percentage of patients have a history of brain tumors in their families. Children who undergo prophylactic radiation for acute lymphocytic leukemia (ALL) have a 22-fold increased risk of having a central nervous system cancer in the next 5 to 10 years.

Pituitary adenoma radiation therapy has been proven to increase the chance of glioma development by 16 times. Turcot syndrome, p53 mutations (Li – Fraumeni), and NF1 syndrome, for example, have a genetic vulnerability to glioma formation. Approximately 66 percent of low-grade astrocytomas have p53 mutations.

Genetics

Prognostic Factors

Low-grade tumors have a good prognosis, with survival periods of 7 to 8 years after surgery. The goal of treatment for anaplastic astrocytoma is to improve symptoms.

The use of radiotherapy to treat partly resected malignancies improves postoperative survival. After post-surgery radiotherapy, survival rates are approximately double those after merely surgical intervention (5 vs. 2.2 years).

The prognosis of a particular type of tumor is also influenced by genetics. PCV [procarbazine, CCNU (Iomustine), and vincristine] is more effective against oligodendroglioma with Ch 1p 1 9q alterations. Individualized tumor therapy will soon be possible thanks to advances in genetics.

The level of kallikrein is linked to the patient’s prognosis:

  • Poor outcomes are associated with increased KLK6 / KLK7-IR.
  • Immunoreaction with KLK6/9 resulted in a reduction in survival.

Clinical History

Age Group: 

  • Astrocytomas can develop at any age, however some forms may be more common in certain age groups. 
  • Low-grade astrocytomas (Grade I and II) may be more common in younger individuals, including children and young adults. 
  • High-grade astrocytomas (Grade III and IV), such as glioblastomas, are more common in older adults, with the risk increasing with age. 

Clinical Presentation: 

  • The clinical presentation of astrocytomas can vary based on the tumor’s location, size, and grade. 
  • Common symptoms include headaches, seizures, changes in personality or behavior, cognitive decline, motor deficits, and problems with vision or speech. 
  • The symptoms may develop gradually or suddenly, depending on the tumor’s growth rate. 

Physical Examination

Neurological Examination: 

  • Mental Status: Evaluate the patient’s level of consciousness, orientation, and cognitive function. 
  • Cranial Nerves: Assess each cranial nerve individually, looking for abnormalities in vision, eye movements, facial sensation and movement, hearing, and swallowing. 
  • Motor Function: Evaluate strength, tone, and coordination in all extremities. Assess for any signs of weakness or paralysis. 
  • Reflexes: Check deep tendon reflexes, such as the knee jerk reflex (patellar reflex) and the biceps reflex. 
  • Coordination and Balance: Assess coordination through tasks such as finger-to-nose testing and heel-to-shin testing. 
  • Sensory Function: Test sensation to touch, pain, and temperature in different areas of the body. 

Visual Examination: 

  • Assess visual acuity, visual fields, and eye movements. 
  • Optic disc examination using ophthalmoscopy may reveal signs of increased intracranial pressure. 

Gait and Balance: 

  • Observe the patient’s gait and balance, as abnormalities may indicate cerebellar or brainstem involvement. 

General Examination: 

  • To evaluate general health and find any non-neurological complaints or comorbidities, do a thorough physical examination. 

Vital Signs: 

  • Keep an eye on your vital indicators, such as your temperature, heart rate, breathing rate, and blood pressure. 

Age group

Associated comorbidity

  • There may not be specific comorbidities associated with astrocytomas, but certain genetic or environmental factors could contribute to their development. 
  • Radiation exposure, genetic predisposition (e.g., neurofibromatosis), or a family history of brain tumors may be relevant in some cases. 

Associated activity

Acuity of presentation

  • Low-grade astrocytomas often present with more indolent and slow-growing symptoms. Patients may experience mild, chronic symptoms over an extended period. 
  • High-grade astrocytomas, especially glioblastomas (Grade IV), tend to present more acutely with rapidly progressing symptoms. 
  • Glioblastomas are often associated with a high degree of vascularity, which contributes to their aggressive nature and rapid growth. 

Differential Diagnoses

Metastatic Brain Tumors: Metastases from primary cancers elsewhere in the body, such as lung, breast, or melanoma. 

Infectious Causes: 

  • Brain abscess: A localized collection of pus within the brain tissue, often caused by bacterial or fungal infection. 
  • Neurocysticercosis: Infection of the brain with the larvae of the pork tapeworm, Taenia solium. 
  • Toxoplasmosis: Caused by Toxoplasma gondii, a parasite that may infect the brain, especially in those with weakened immune systems. 

Vascular Lesions: 

  • Arteriovenous malformation (AVM) 
  • Cerebral aneurysm 
  • Cavernous malformation 

Inflammatory and Autoimmune Disorders: 

  • Multiple sclerosis (MS) 
  • Acute disseminated encephalomyelitis (ADEM) 
  • Autoimmune encephalitis 

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

Surgery: 

  • Grade I and II Astrocytomas: Surgical excision is frequently an option for low-grade tumors, with the aim of eliminating the tumor as much as possible while maintaining neurological function. 
  • Grade III and IV Astrocytomas: Surgical resection is usually performed, but complete removal may be challenging for higher-grade tumors due to their infiltrative nature. A biopsy can also be done to take a sample of tissue for a diagnosis. 

Radiation Therapy: 

  • Grade II-IV Astrocytomas: Radiation therapy is commonly used postoperatively, especially for high-grade tumors like glioblastomas (Grade IV). It helps to target any remaining tumor cells and delay recurrence. 
  • In some cases, radiation may be used as the primary treatment for tumors that are not surgically accessible. 

Chemotherapy: 

  • Grade III and IV Astrocytomas: Chemotherapy, often with temozolomide, is a standard treatment for high-grade astrocytomas, particularly glioblastomas. It is commonly used in conjunction with radiation therapy. 
  • Chemotherapy may also be considered for some lower-grade tumors, especially if they recur or progress despite surgery and radiation. 

Targeted Therapies: 

  • Emerging targeted therapies may be considered based on specific molecular characteristics of the tumor. Molecular profiling is increasingly used to identify genetic mutations and alterations that may guide treatment decisions. 

Clinical Trials: 

  • Some patients, particularly those with recurring or resistant malignancies, may be able to take part in clinical trials. Experimental therapies and novel treatment approaches are often investigated in clinical trials. 

Supportive Care: 

  • Symptomatic and supportive care is an integral part of managing astrocytomas. This may include medications for pain, anti-seizure medications, and supportive therapies to address side effects of treatment. 

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Use of a non-pharmacological approach for treating Astrocytoma

  • Surgical Interventions: The main treatment option for astrocytomas is surgery, which can be used in several ways to either eliminate or minimize the tumor. Advanced neurosurgical techniques, such as awake craniotomy or intraoperative imaging, can help preserve neurological function during tumor resection. 
  • Radiation Therapy: Advanced radiation therapy techniques, such as stereotactic radiosurgery (SRS) or intensity-modulated radiation therapy (IMRT), can precisely target tumors while sparing surrounding healthy tissue. This can help minimize treatment-related side effects and improve outcomes. 
  • Physical Therapy: It can help maintain or improve physical function, mobility, and strength. It may be particularly beneficial for patients who experience motor deficits or weakness due to the tumor or its treatment. 
  • Occupational Therapy: Its major goal is to increase the patient’s capacity for carrying out everyday tasks and preserving their independence. It can help develop strategies for managing cognitive changes, fine motor skills, and activities of daily living. 
  • Speech Therapy: It may be necessary for patients who experience speech or swallowing difficulties as a result of the tumor or its treatment. Speech therapists can offer exercises and methods to enhance swallowing and speaking abilities. 
  • Cognitive Rehabilitation: Cognitive rehabilitation programs can assist patients in managing cognitive deficits, memory problems, and other cognitive impairments that may arise due to the tumor or its treatment. These programs may include cognitive exercises, memory strategies, and compensatory techniques. 
  • Psychosocial Support: In order to assist individuals and their families deal with the emotional challenges that come with receiving a brain tumor diagnosis, psychosocial therapies such as counseling and support groups might be helpful. Addressing anxiety, depression, and stress can improve overall well-being and quality of life. 
  • Nutritional Support: Patients receiving therapy for astrocytomas must consume a healthy diet. A qualified dietitian may offer advice on how to sustain a healthy diet, control side effects of therapy including nausea and appetite loss, and promote general health and wellbeing. 

Role of Anticonvulsants in the treatment of Astrocytoma

Anticonvulsants play a significant role in the treatment of astrocytomas, primarily in managing seizures, which are a common symptom associated with these brain tumors.Astrocytomas, particularly those located in or near regions of the brain responsible for controlling seizures, can cause epileptic activity. Seizures can significantly impact the patient’s quality of life and may require prompt and effective management. Anticonvulsants help people with astrocytomas avoid seizures or lessen their frequency and intensity. 

  • Phenytoin (Dilantin): Phenytoin is one of the most commonly prescribed anticonvulsants for managing seizures associated with brain tumors, including astrocytomas. It works by stabilizing neuronal membranes and reducing neuronal excitability. 
  • Levetiracetam (Keppra): Levetiracetam is another frequently used anticonvulsant that is well-tolerated and has a broad spectrum of activity. It is often preferred in patients who may have adverse reactions to phenytoin or other anticonvulsants. 
  • Valproic Acid (Depakote): Valproic acid is another anticonvulsant that may be used in the management of seizures associated with astrocytomas. It functions by raising the brain’s concentration of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). 
  • Carbamazepine (Tegretol): Carbamazepine is an anticonvulsant that may be used in the treatment of seizures related to astrocytomas. It works by blocking voltage-gated sodium channels, thereby stabilizing neuronal membranes and reducing neuronal excitability. 

Role of Corticosteroids in the treatment of Astrocytoma

Corticosteroids play a crucial role in the treatment of astrocytomas, particularly in managing symptoms related to tumor-induced brain edema. Astrocytomas, especially high-grade tumors like glioblastomas, can cause the disruption of the blood-brain barrier and lead to edema (fluid accumulation) in the surrounding brain tissue. Corticosteroids, such as dexamethasone, are potent anti-inflammatory agents that can reduce the permeability of blood vessels, resulting in a decrease in edema and associated symptoms. 

Dexamethasone: 

  • Dexamethasone is the most commonly used corticosteroid in the treatment of astrocytomas. It is a potent synthetic glucocorticoid with anti-inflammatory and immunosuppressive properties. 
  • Usually given orally or intravenously, the dose is modified in accordance with each patient’s reaction and the severity of their symptoms. 

Role of Antineoplastic Agent, Alkylating Agent in the treatment of Astrocytoma

Alkylating agents are cytotoxic drugs that form covalent bonds with DNA molecules, leading to DNA cross-linking and strand breaks. By inducing damage to the DNA, alkylating agents disrupt the ability of cancer cells to replicate and undergo mitosis, thereby inhibiting tumor growth. Alkylating agents are often used in combination with other therapeutic modalities, such as surgery and radiation therapy, to target different aspects of the tumor. Astrocytomas, particularly high-grade gliomas such as glioblastomas (Grade IV), are known for their aggressive and infiltrative nature. Alkylating agents can be effective in targeting rapidly dividing tumor cells and reducing tumor burden. 

  • Temozolomide: Temozolomide is an oral alkylating agent commonly used in the treatment of astrocytomas, especially glioblastomas. It has the benefit of being able to pass across the blood-brain barrier and get to the tumor cells located in the brain’s central nervous system.Temozolomide is often administered concomitantly with radiation therapy in the initial treatment of glioblastomas and may be continued as maintenance therapy. The drug is well-tolerated, and its use is associated with improvements in overall survival and progression-free survival in certain cases. 
  • Carmustine (BCNU): Carmustine is an alkylating agent that can be used for the treatment of astrocytomas. It is often administered intravenously or implanted directly into the tumor site using biodegradable wafers during surgery. BCNU is sometimes used in combination with other chemotherapy agents or radiation therapy in the management of gliomas. 
  • Lomustine (CCNU): Lomustine is another alkylating agent that can be used in the treatment of astrocytomas. It is an oral medication and is often employed in combination regimens for high-grade gliomas. 

Use of Intervention with a procedure in treating Astrocytoma

Stereotactic Biopsy: 

  • A minimally invasive technique called stereotactic biopsy is used to remove tissue samples from brain tumors that are deep-seated or difficult to approach, such as astrocytomas. 
  • This procedure involves using imaging guidance (such as MRI or CT scans) and specialized instruments to precisely target and extract tissue samples for pathological analysis. 
  • Stereotactic biopsy may be performed when surgical resection is not feasible or safe due to the tumor’s location or the patient’s overall health, providing valuable diagnostic information for treatment planning. 

Stereotactic Radiosurgery (SRS): 

  • A minimally invasive technique called stereotactic biopsy is used to remove tissue samples from brain tumors that are deep-seated or difficult to approach, such as astrocytomas. 
  • Small-to moderate-sized astrocytomas are frequently treated non-invasively with SRS, especially when surgical resection is not an option or when the tumors are recurring. 
  • Targeting remaining tumor cells after surgical excision, it can be used as a complement therapy or as the main mode of treatment. 

Interstitial Brachytherapy: 

  • Radiation sources are inserted immediately into the tumor or its cavity after surgical excision in an approach known as interstitial brachytherapy. 
  • This procedure allows for the delivery of high-dose radiation to the tumor bed while minimizing exposure to surrounding healthy tissue. 
  • Interstitial brachytherapy may be used in the management of recurrent or residual astrocytomas, particularly in cases where external beam radiation therapy (EBRT) is not feasible or has been previously administered. 

Chemotherapy Infusion: 

  • Intracavitary or intratumoral chemotherapy infusion involves the direct administration of chemotherapy agents into the tumor cavity or the tumor site following surgical resection. 
  • This technique allows for the delivery of high concentrations of chemotherapy agents to the tumor while minimizing systemic toxicity. 
  • Chemotherapy infusion may be employed as a localized treatment option for astrocytomas, particularly in cases of recurrent or progressive disease. 

Percutaneous Radiofrequency Ablation (RFA): 

  • Percutaneous RFA involves the insertion of a radiofrequency probe into the tumor under imaging guidance to deliver thermal energy, resulting in tumor destruction. 
  • This minimally invasive technique may be used in selected cases of small or accessible astrocytomas, particularly in recurrent tumors or as a palliative treatment option to alleviate symptoms. 

Implantable Chemotherapy Devices: 

  • Implantable chemotherapy devices, such as biodegradable wafers containing chemotherapy agents, can be placed directly into the tumor cavity following surgical resection. 
  • These devices allow for the sustained release of chemotherapy agents at the tumor site, providing localized treatment while minimizing systemic side effects. 

Use of phases in managing Astrocytoma

Diagnostic Phase: 

  • This phase involves the initial evaluation and diagnosis of the astrocytoma. 
  • To see the tumor and determine its features, imaging tests like CT or MRI scans are included. 
  • A biopsy may be performed to obtain tissue samples for precise diagnosis and grading of the tumor. 

Staging Phase: 

  • Once the diagnosis is confirmed, the tumor is staged based on its size, location, and extent of spread within the brain. 
  • Staging helps determine the appropriate treatment approach and prognosis. 

Treatment Planning Phase: 

  • During this stage, a multidisciplinary group of experts creates a customized treatment program based on the features of the tumor and the general health of the patient. 
  • Options for treatment might include chemotherapy, radiation therapy, surgery, or a mix of these. 

Surgical Phase: 

  • In order to eliminate the tumor as much as possible while maintaining neurological function, surgical excision of the tumor is frequently attempted when it is practical. 
  • The surgical phase may also include biopsies for histological analysis to guide further treatment decisions. 

Adjuvant Therapy Phase: 

  • Adjuvant treatments, such as chemotherapy and radiation therapy, may be used after surgery to target any cancer cells that may still be present and lower the chance of a tumor recurrence. 
  • The timing and duration of adjuvant therapy depend on factors such as tumor grade and extent of resection. 

Monitoring and Surveillance Phase: 

  • After completing treatment, patients enter a phase of ongoing monitoring and surveillance to detect any signs of tumor recurrence or progression. 
  • Regular imaging studies and clinical evaluations are conducted to assess treatment response and overall health status. 

Supportive Care Phase: 

  • Throughout the treatment journey, supportive care measures are implemented to manage symptoms, alleviate side effects of treatment, and optimize quality of life. 
  • This phase includes supportive therapies such as pain management, nutritional support, and psychosocial interventions. 

Palliative Care Phase: 

  • In cases where the astrocytoma is advanced or recurrent, palliative care becomes a central component of management. 
  • Controlling symptoms, managing pain, and attending to patients’ and their families’ spiritual and emotional needs are the main goals of palliative care. 

Medication

Media Gallary