Grading & Prognosis
Astrocytomas are graded as follows:
- Grade 1 astrocytomas (slow growing)
- Grade 2 astrocytoma (moderately fast growing)
- Grade 3 anaplastic astrocytoma
- Grade 4 astrocytoma, also called glioblastoma multiforme or GMB (very fast growing).
Brain tumor prognosis (outlook) depends on many factors including tumor location, how easily it can be surgically removed, patient age, responsiveness to radiotherapy/ chemotherapy and tumor grade. Glioblastoma is the least responsive to treatment and has the worst prognosis. Low grade astrocytomas (grade 1 or 2) can often be completely removed surgically and have a better outlook.
Recent statistics on brain tumor survival rate show that around 65% of patients with low grade astrocytoma live for at least 5 years and have no tumor growth during that time. However, these low grade cancers may come back or transform into high grade tumors at a later stage. In grade 3 astrocytomas (anaplastic astrocytoma brain tumor) about 27% of patients survive for at least 5 years. The most aggressive grade 4 astrocytoma (GMB) has an average life expectancy of under a year, with less than 4% of patients being alive 5 years after diagnosis.
Symptoms, Diagnosis and Treatment of Anaplastic Astrocytoma
Symptoms of a brain tumor include altered mental state, cognitive impairment, seizures, headaches, impaired vision and motor skills. Symptoms depend on the location of the tumor in the CNS.
Diagnosis is generally by clinical and radiographic examination (CT scan or MRI). However this must be confirmed by histology. Despite advances in brain tumor imaging, a definite diagnosis requires microscopic examination of tumor tissue. Anaplastic astrocytoma is a distinct histological classification, being characterized by abundant pleomorphic astrocytes with evidence of mitosis.
Brain tumor treatment is usually surgical resection, followed by radiotherapy and chemotherapy. Despite treatment, nearly all high-grade astrocytomas show tumor recurrence or progression within a few years. Recurrent tumors are less responsive to treatment.
No specific causes/risk factors for anaplastic astrocytoma brain tumor have been identified to date. The poor success rate in treatment is attributed to the high molecular variability of these tumors. Also, because of the location in the CNS, it can be difficult to deliver treatment to the tumor site. It is hoped that increased knowledge of how these tumors behave at the molecular level will lead to improved treatment and outcome for these patients.
Organizations and Support
Samantha Dickson Brain Tumour Trust is a UK charity providing information and support to people living with brain tumors and providing funds for scientific research. https://braintumourtrust.co.uk
National Brain Tumor Society is a US organization that provides a resource to patients, families, researchers and health care professionals, as well as funding research into brain cancer. www.braintumor.org/
Diagnosis and treatment of high-grade astrocytoma. S.Sathornsumetee, J.Rich, D.Reardon. Neurol Clin. 2007; Vol 25, P1111-39
Cancer Research UK www.cancerhelp.org.uk
Anaplastic astrocytoma: diagnosis, prognosis and management. S.See & M.Gilbert. Seminars in Oncology, 2004, Vol 31, P618-34.