Astrocytoma: Symptoms, Grades, Causes & Treatment Options — Complete Guide
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What Is Astrocytoma?
Astrocytoma is a type of cancer of the brain or spinal cord that begins in star-shaped support cells called astrocytes. It is graded 1 to 4: grade 1 tumors grow slowly and are often cured with surgery alone, while grade 4, called glioblastoma, is the most aggressive. Diagnosis requires MRI plus biopsy, and treatment depends on the tumor. [1]
What the research says
Adding temozolomide to radiation extended survival in glioblastoma. In 573 patients with newly diagnosed glioblastoma, median survival was 14.6 months with radiotherapy plus temozolomide versus 12.1 months with radiotherapy alone (hazard ratio for death 0.63), and two-year survival was 26.5% versus 10.4%. (Stupp et al., N Engl J Med, 2005) [3]
Tumor-Treating Fields added further survival. In 695 patients who had completed standard radiochemotherapy, Tumor-Treating Fields plus maintenance temozolomide gave a median overall survival of 20.9 months versus 16.0 months with temozolomide alone (HR 0.63), and median progression-free survival of 6.7 versus 4.0 months; mild to moderate skin toxicity under the device arrays occurred in 52% of patients. (Stupp et al., JAMA, 2017) [4]
An IDH inhibitor slowed progression in grade 2 IDH-mutant tumors. The randomized, placebo-controlled trial behind the FDA's 2024 approval of vorasidenib for grade 2 IDH-mutant astrocytoma or oligodendroglioma found a hazard ratio of 0.39 (95% CI 0.27–0.56, P<0.0001) for radiographic progression-free survival among 331 patients assessed. (Barbato et al., Clin Cancer Res, 2025) [5]
Astrocytoma at a Glance
What it is: Brain or spinal cord cancer starting in astrocytes — star-shaped cells that support nerve cells.
Family: Part of the glioma group of brain tumors.
Grades: 1 (pilocytic) to 4 (glioblastoma), based on growth speed.
Symptoms: Seizures, headaches, weakness, vision/speech changes, mood and memory shifts — depend on tumor location.
Causes: DNA mutations; most cases appear by chance; no proven lifestyle or environmental link.
Confirmed by: Biopsy with molecular testing (the only way to know type and grade).
Main scan: MRI with contrast; CT used if MRI isn't possible or in emergencies.
Treatment: Surgery, radiation, chemotherapy, targeted therapy, watchful waiting, or clinical trials.
What Is Astrocytoma?
Astrocytoma is a type of cancer that can occur in the brain or spinal cord. It begins in cells called astrocytes that support nerve cells. Some astrocytomas grow very slowly, while others can be aggressive cancers that grow quickly.
Astrocytoma is part of a larger group of brain tumors called gliomas — tumors that start in the cells that help support nerve cells.
Astrocytoma is graded 1 to 4 based on how fast the tumors grow. Grade 4 astrocytoma, also called glioblastoma, grows the fastest and is the most aggressive. Lower grade astrocytomas, grades 1 to 3, usually grow more slowly and often have a better outlook than glioblastoma. Treatment and prognosis depend on the tumor's grade, size, location, and molecular features.
What are the symptoms of astrocytoma?
Astrocytoma symptoms often start out as mild and depend on where the tumor is in the brain or spinal cord. These symptoms can change as the tumor grows. Early symptoms come from local irritation of nearby brain tissue; later symptoms happen as the tumor grows and pressure builds in the brain or spinal canal. Low-grade astrocytomas can grow larger before causing symptoms, while high-grade tumors tend to cause symptoms sooner.
Early Symptoms
New seizures — often the first sign in slow-growing tumors
Subtle changes in thinking, mood, or memory
Mild headaches
Difficulty finding the right words to say
Changes in vision
Clumsiness on one side of the body
Pain in the neck or back that begins slowly
Tingling or numbness that travels into an arm or leg
Later Symptoms as the Tumor Grows
Headaches that get worse, especially in the morning or with coughing or straining
Nausea and vomiting — a result of increased pressure
Increasing weakness
Speech or vision troubles
Cognitive decline — changes in memory, thinking, or concentration
Worsening balance
Bowel or bladder changes
Symptoms by Tumor Location
Back and lower part of brain: Trouble with balance and coordination (stumbling, shaky movements); headache, nausea, and vomiting from pressure in the brain.
Brainstem: Double vision or other eye movement issues; facial weakness or numbness; difficulty speaking or swallowing; walking and balance difficulty; weakness.
Spinal cord: Back or neck pain that slowly worsens; pain spreading into an arm or leg; numbness and tingling; weakness; poor balance, falls, unsteadiness; bowel or bladder changes (later).
These symptoms aren't specific to astrocytoma and can happen with many types of brain tumors. New or worsening symptoms — a first-time seizure, vision changes, speech trouble, one-sided weakness, or headaches that are worse in the morning — should be checked by a healthcare professional.
Can Swelling Around the Tumor Worsen Symptoms?
Yes. Swelling of brain tissue around the tumor is called peritumoral edema. It can make symptoms worse or cause new ones — headaches, weakness, speech trouble, or vision changes. The swelling increases pressure inside the skull and can stretch or irritate nearby brain pathways. Short courses of steroid medicines may be used to reduce swelling and relieve symptoms. Edema is more common in high-grade astrocytomas and contributes to symptoms even when the tumor itself is not very large.
Children vs. Adults
Pilocytic astrocytomas — grade 1 tumors — are more common in children and teens (rare in adults). Because they grow slowly, symptoms often develop gradually over weeks or months. Children may have:
Headaches, especially in the morning
Balance problems or clumsiness if the tumor is in the cerebellum
Nausea, vomiting, or irritability from pressure in the brain
Vision problems if the tumor affects the optic pathway
In very young children, parents may notice changes in coordination, school performance, or behavior. In adults, astrocytomas more often develop in a different part of the brain, causing new seizures, speech issues, or changes in thinking or personality as early symptoms.
What Causes Astrocytoma?
The exact cause often isn't known. Astrocytoma starts when brain or spinal cord cells called astrocytes begin to grow and divide in an unusual and uncontrolled way.
A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA says to grow and multiply at a set rate and to die at a set time. In tumor cells, changes in the DNA — called mutations — give different instructions. The changed genes make the cells divide when they shouldn't and live longer than they should, causing too many cells to group together and form a tumor. As the tumor grows, it can press on nearby areas of the brain or spinal cord; sometimes the DNA changes turn tumor cells into cancer cells that invade and destroy healthy tissue.
Scientists have found certain gene changes that drive this unhealthy growth:
IDH1 and IDH2: Affect how tumor cells make and use energy; common in many low-grade astrocytomas.
TP53 and ATRX: Affect how cells repair DNA and manage cell growth.
MGMT silencing: Affects how tumor cells repair DNA damage and can affect how well treatment works.
BRAF (in children): Often seen in slow-growing pilocytic astrocytomas; develop inside the tumor and are not usually passed down in families.
In pilocytic astrocytoma, a growth signal in the cell gets stuck "on," so the cells grow slowly in one spot. High-grade astrocytomas develop after many harmful DNA changes build up, making the cells grow quickly and spread into nearby brain tissue.
What Do the IDH Results Mean?
IDH is a gene found in cells, in two forms: IDH1 and IDH2. When a tumor is IDH wild type, the gene looks healthy with no change — glioblastoma is an IDH wild-type tumor. When a tumor is IDH mutant, there is a change in the IDH1 or IDH2 gene; the tumor is then named astrocytoma, IDH mutant and assigned a grade of 2, 3, or 4. IDH testing helps the healthcare team classify the tumor and predict how it may behave.
What are the risk factors for astrocytoma?
Risk factors for astrocytoma include past high-dose radiation to the head or neck, age and certain rare inherited conditions such as neurofibromatosis type 1 (NF1).
High-dose radiation to the head or neck: History of high-dose ionizing radiation therapy for another cancer raises risk — especially if it was near the head or neck and especially during childhood.
Age: Children more often have low-grade (slow-growing) tumors; adults more often have high-grade (aggressive) tumors. Most high-grade astrocytomas are diagnosed after age 40.
Inherited conditions: Certain rare conditions that run in families may increase risk: neurofibromatosis type 1 (NF1), Lynch syndrome, Turcot syndrome, and tuberous sclerosis.
No proven lifestyle or environmental link. There's no proven link between astrocytoma and lifestyle factors such as diet, exercise, or smoking. Suspected environmental risks — chemical exposures or cellphone use — have not been shown to cause astrocytoma. Most cases appear by chance, without a clear outside trigger.
How is astrocytoma diagnosed?
Astrocytoma is diagnosed using a neurological exam, imaging scans, and a biopsy, which together confirm the tumor's type, grade, and genetic features [2].
Neurological Exam
The healthcare team asks about your symptoms and tests your vision, hearing, balance, coordination, strength, and reflexes. Trouble in one or more areas may help show the part of the brain affected by the tumor.
Imaging Tests
A brain MRI is often used to diagnose brain tumors. Special types of MRI — functional MRI, perfusion MRI, or MR spectroscopy — may also be used, along with CT and positron emission tomography (PET) scans.
MRI with contrast: The main scan for spotting and studying an astrocytoma — shows brain and spinal cord tissue in much greater detail, and clearly reveals both small slow-growing and aggressive tumors.
CT: Used mainly if MRI isn't possible or in emergencies.
On MRI, a pilocytic astrocytoma looks smoother and more organized — often like a cyst (a round or oval mass with a fluid pocket), with clear borders and less swelling. Higher grade tumors look rougher — uneven, spreading into nearby tissue with blurred edges, swelling around the tumor, and patchy bright areas after contrast from dead cells or unusual new blood vessels.
Biopsy and Molecular Testing
A biopsy takes a sample of tissue from the tumor for testing. After imaging shows a possible tumor, a biopsy is needed to confirm the diagnosis and learn more about the tumor's molecular features. The sample often is taken during surgery to remove the astrocytoma; if the tumor is in a hard-to-reach spot, a needle might be used instead. The tissue goes to a lab for review under a microscope.
A biopsy is the only way to confirm the diagnosis of astrocytoma and find out what type and grade it is.
Molecular testing studies the tumor's genes and molecules:
IDH testing: A change in the IDH1 or IDH2 gene — tumors with this change usually grow more slowly and respond better to treatment.
MGMT promoter methylation: Whether the DNA repair gene is "turned off" — if it is, the tumor may respond better to chemotherapy with temozolomide.
1p/19q codeletion: Missing parts of chromosomes 1 and 19 — helps confirm whether the tumor is an oligodendroglioma, which often responds well to radiation and chemotherapy.
Testing on the biopsy sample helps predict how the tumor will grow and behave, and which treatments are most likely to be effective.
Can Blood Tests or Spinal Taps Detect Astrocytoma?
No — spinal taps and blood tests usually can't detect an astrocytoma. These tumors form inside the brain or spinal cord, and routine blood work or spinal fluid tests don't show clear signs. In rare cases, a healthcare professional may do a spinal tap (lumbar puncture) to check for tumor cells in the cerebrospinal fluid if there's concern the tumor has spread within the brain or spinal canal. Blood tests are mainly used to check general health and how the body is handling treatment.
How is astrocytoma treated based on grade and location?
Treatment depends on the tumor's grade, size, and location. Common treatments include surgery, radiation therapy, and chemotherapy; in some cases, targeted therapy or clinical trials [2].
The Four Main Treatments
Surgery: A neurosurgeon works to remove as much of the astrocytoma as possible, with the goal of removing the whole tumor. If it's in a hard-to-reach spot, full removal may be too risky — but even partial removal can ease symptoms. For some people, surgery is the only treatment needed; for others, more treatments kill remaining tumor cells and lower the risk of return.
Radiation therapy: Powerful energy beams (X-rays, protons, and other sources) kill tumor cells. You lie on a table while a machine moves around you, sending beams to exact points in the brain; each treatment takes only a few minutes. It may follow surgery if the cancer wasn't fully removed or recurrence risk is high, and may pair with chemotherapy for fast-growing cancers — or serve as a main treatment when surgery isn't possible.
Chemotherapy: Strong medicines kill tumor cells; taken as pills, given through a vein, or sometimes placed as a circular wafer in the brain during surgery, where it slowly dissolves and releases the medicine. Often used after surgery to kill remaining cells, and with radiation for fast-growing tumors.
Supportive (palliative) care: A team of specialists helps manage pain and other symptoms of a serious illness — given alongside surgery, chemotherapy, or radiation, and often beginning when treatment starts, without waiting for complications to appear.
Treatment by Grade
Grade 1: Surgery is often the only treatment needed. Slow-growing and well defined, so often removable completely; if the entire tumor is taken out, people often need no further treatment.
Grade 2: Surgery, often followed by radiation therapy, chemotherapy, or both. These tumors spread into nearby tissue, making complete removal hard; added treatments kill remaining cells and lower recurrence risk.
Grades 3 and 4: Often a combination of surgery, radiation therapy, and the chemotherapy medicine temozolomide — a more aggressive approach for faster-growing tumors. Targeted therapies such as IDH inhibitors or clinical trials also may be considered.
Watchful Waiting
Watchful waiting (active surveillance) can be safe for some small, slow-growing, low-grade tumors when the risks of surgery outweigh the benefits — but close monitoring is essential, and treatment should begin at the first sign of change. It may be considered when:
The tumor is small and symptom-free — found by chance, doesn't affect brain function; the team monitors closely with MRI scans.
Surgery would carry high risk — the tumor sits in a deep or critical brain area where surgery could harm important functions.
The diagnosis is uncertain — imaging suggests a low-grade tumor but a biopsy would be risky.
Treatment for Spinal Cord and Brainstem Tumors
Spinal cord: Surgery to remove as much tumor as is safely possible, with radiation or chemotherapy if the tumor can't be fully removed or is high grade. The tumor grows inside the spinal cord, so surgeons must protect nerve pathways that control feeling and movement.
Brainstem: Often biopsy only or very limited surgery, if safe; radiation is the main treatment, and chemotherapy may be added, especially in children. The brainstem controls breathing, heart rate, and swallowing, so surgery is often too risky.
Clinical Trials and Emerging Treatments
Researchers are testing new treatments through clinical trials — especially for people whose tumor returns or stops responding to standard treatments:
Targeted therapy — medicines designed to act on certain proteins or genes in tumor cells, such as IDH inhibitors, which may help slow tumor growth in tumors with the IDH gene change.
Immunotherapy — helps your body's defense system fight the tumor, including vaccines, chimeric antigen receptor (CAR)-T cell therapy, and viral therapies that target tumor cells directly.
Tumor-Treating Fields (TTFields) — low-intensity electrical fields that disrupt how cancer cells grow and divide; already approved for glioblastoma, with studies showing longer survival when used with standard treatments.
Better uses of temozolomide — researchers are studying ways to make it work even better, such as changing how it's given or combining it with new treatments.
Because these treatments are still being studied, their risks and benefits may not yet be fully known. Your healthcare team can help you decide if a clinical trial is right for you.
How should you prepare for an astrocytoma appointment?
If your healthcare professional suspects astrocytoma, you'll likely be referred to a specialist — a cancer doctor called an oncologist and/or a brain surgeon called a neurosurgeon. Because appointments may be quick, come prepared.
What You Can Do
Ask ahead of time if there's anything you need to do before the appointment, such as not eating before a specific test
List your symptoms, even ones that don't seem related
List key personal information, including major stresses, recent life changes, and family medical history
List all medicines, vitamins, or supplements you take, including doses
List questions you'd like to ask
Take a trusted family member or friend along, if possible, to help remember the information you're given
Questions to Ask Your Doctor
Do I have cancer?
If the tumor isn't cancerous, do I still need to have it removed?
Do I need more tests?
What are my treatment options?
What are the potential risks or side effects of these treatment options?
Will any of these treatments cure my cancer?
Can I have a copy of my pathology report?
How much time can I take to consider my treatment options?
Are there brochures or other printed materials I can take with me? What websites do you recommend?
What would happen if I decide not to have treatment?
Questions the Doctor Will Likely Ask
When did your symptoms begin?
Do your symptoms come and go, or are they constant?
How severe are your symptoms?
What, if anything, seems to improve your symptoms?
What, if anything, appears to worsen your symptoms?
FAQ: Astrocytoma Questions People Also Ask
What is an astrocytoma?
Astrocytoma is a type of cancer that can occur in the brain or spinal cord. It begins in cells called astrocytes — star-shaped cells that support nerve cells — and is part of a larger group of brain tumors called gliomas.
What are the grades of astrocytoma?
Astrocytomas are graded 1 to 4 based on how fast the tumor cells grow. Grade 1 (pilocytic astrocytoma) grows slowly with clear edges and is often cured with surgery alone. Grades 2 and 3 grow into nearby tissue at increasing speeds. Grade 4, called glioblastoma, is the most aggressive and most common in adults.
What are the first symptoms of astrocytoma?
Early symptoms often include new seizures, subtle changes in thinking, mood, or memory, mild headaches, difficulty finding the right words, changes in vision, clumsiness on one side of the body, and slowly developing neck or back pain.
What causes astrocytoma?
Astrocytoma starts when astrocytes develop DNA changes called mutations that make cells divide when they shouldn't and live longer than they should. Key gene changes include IDH1 and IDH2, TP53, ATRX, MGMT, and BRAF. Most cases appear by chance — there's no proven link to diet, smoking, or cellphone use.
How is astrocytoma diagnosed?
Diagnosis uses a neurological exam, imaging scans (mainly MRI with contrast), and a biopsy with molecular testing. A biopsy is the only way to confirm the diagnosis and determine the tumor's type and grade; blood tests and spinal taps usually can't detect astrocytoma.
How is astrocytoma treated?
Treatment depends on the tumor's grade, size, and location, and commonly combines surgery, radiation therapy, and chemotherapy such as temozolomide. Grade 1 tumors often need surgery alone, small low-grade tumors may be monitored with watchful waiting, and clinical trials offer emerging options like IDH inhibitors and Tumor-Treating Fields.
Can an astrocytoma be cured?
Grade 1 pilocytic astrocytomas are often treated successfully with surgery alone, and most people are cured and live a typical lifespan. Higher grade tumors require more aggressive treatment, and while they may respond well, they have a greater chance of returning.
Conclusion
By now, you understand the essentials of this complex but increasingly well-understood condition:
Grade drives everything. An astrocytoma's behavior — from slow-growing and often curable to fast-growing glioblastoma — is captured in its 1-to-4 grade, and treatment follows from it.
Location shapes the symptoms. The same tumor behaves differently in the back of the brain, the brainstem, or the spinal cord — so watch for new seizures, morning headaches, one-sided weakness, and speech or vision changes.
The biopsy tells the real story. Imaging finds the tumor, but only molecular testing of a biopsy sample reveals its genes (IDH, MGMT, and others) — and those results increasingly steer modern, targeted treatment.
This guide has walked you through the symptoms by location and grade, the DNA mechanics behind the disease, the diagnosis pathway, and the full treatment landscape from surgery to clinical trials.
The information in this article is for general educational purposes only and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your individual condition.
References
Mayo Clinic Staff. Astrocytoma - Symptoms and causes. Mayo Clinic. November 7, 2025. https://www.mayoclinic.org/diseases-conditions/astrocytoma/symptoms-causes/syc-20576675
Mayo Clinic Staff. Astrocytoma - Diagnosis and treatment. Mayo Clinic. November 7, 2025. https://www.mayoclinic.org/diseases-conditions/astrocytoma/diagnosis-treatment/drc-20576715
Stupp R, Mason WP, van den Bent MJ, et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N Engl J Med. 2005;352(10):987-996. PMID: 15758009. DOI: 10.1056/NEJMoa043330.
Stupp R, Taillibert S, Kanner A, et al. Effect of Tumor-Treating Fields Plus Maintenance Temozolomide vs Maintenance Temozolomide Alone on Survival in Patients With Glioblastoma: A Randomized Clinical Trial. JAMA. 2017;318(23):2306-2316. PMID: 29260225. DOI: 10.1001/jama.2017.18718.
Barbato MI, Barone AK, Aungst SL, et al. FDA Approval Summary: Vorasidenib for IDH-Mutant Grade 2 Astrocytoma or Oligodendroglioma Following Surgery. Clin Cancer Res. 2025;31(21):4412-4418. PMID: 40911439. DOI: 10.1158/1078-0432.CCR-25-1333.
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