An Overview of Grade 2 Astrocytoma
An astrocytoma is a kind of brain tumor or glioma. Grade 2 astrocytoma is also known as low grade astrocytoma. It is not a common tumor, and it occurs only in about 10 to 15 percent of gliomas. It also has a relatively favorable prognosis in comparison to glioblastomas and anaplastic astrocytomas. These low grade tumors have a tendency to grow very slowly and the symptoms may not show up for several years. There are three treatment options available in such situation. The first is to simply monitor the changes or growth of the tumor through scanning until treatment becomes unavoidable. The second option is surgical removal of the tumor. The third option is shrinking the tumor with radiotherapy.
Symptoms and Diagnosis
Signs and symptoms of low grade astrocytoma may reveal only after a number of years. These may include intermittent headaches, unexplained changes in behavior and personality, visual and hearing difficulties, seizures, and slurred speech or neurologic deficit. The initial diagnosis is usually done through Magnetic Resonance Imaging or MRI. If the tumor is located in critical areas of the brain, such as areas that govern speech or movement, more advanced imaging diagnostic techniques may have to be used to evaluate the astrocytoma.
Biopsy of the tissue is a must in almost all the cases. If there is inaccessibility of the tumor for open surgery, it may require stereotactic needle biopsy. At an advance facility the neurosurgeons may make a combined use of various diagnostic tools and equipment in order to create 3-D image fusion. This helps at the time of operating on the patient and more accurate surgery can be performed.
Factors Determining the Choice of Treatment
If the astrocytoma continues to remain benign over a period of time and reveals minimal change, the best approach may be to continue monitoring the tumor but without any treatment. However, a key factor that may determine the choice of treatment is the location of the tumor. If the tumor is found in a critical portion of the brain, surgery may not be advisable because it may result in serious and permanent damage to the brain. However, if it is determined that the tumor can be removed safely, surgery may be the best treatment option.
Radiotherapy may be advised if the tumor is located in a sensitive area of the brain. But again, even radiotherapy must be avoided as long as the patient is not suffering from any serious symptoms such as blurred vision, seizures, hearing loss, or poor coordination and balance. Most doctors do not recommend chemotherapy as a choice of treatment for low-grade astrocytomas. There is ongoing research to evaluate the benefits of chemotherapy for this problem, but it is not considered to be a standard form of care till now.
Incidence of Low Grade Astrocytoma
In the United States, each year about 5.4 cases per 100,000 adults are diagnosed with gliomas or brain tumors. About 10 to 20 percent of these tumors are low grade astrocytomas in adults, and the incidence is about 25 percent in children. A typical property of gliomas is that they have an association with certain types of phakomatoses, particularly NF-1. These low grade tumors are more commonly found in such patients, especially in the chiasm and optic nerve area.
At a global level too, the incidence of this disease has not revealed any marked difference from that in the U.S. It does not seem to be impacted significantly by nationality or race. However, in case of high grade tumors there is some evidence of the incidence being related to nationality or racial origins. The median rate of survival for patients with these low grade tumors is estimated to be in the range of seven to eight years.