Do You know astrocytomas??

DEFINITION...

Astrocytomas are the most common glioma, and can occur in most parts of the brain (and occasionally in the spinal cord). Astrocytomas originate from cells called astrocytes and are most commonly found in the main part of the brain, the cerebrum. People can develop astrocytomas at any age, though they are more common in adults. Astrocytomas in the base of the brain are more common in young people.

GRADE...

 Grade 1

World Health Organization (WHO) grade 1 astrocytomas (pilocytic astrocytomas, pleomorphic xanthoastrocytomas, subependymal giant cell astrocytomas, and subependymomas) are uncommon tumors which can often be cured by surgically removing the tumor (resection). Even if the surgeon is not able to remove the entire tumor, it may remain inactive or be successfully treated with radiation.



Grade II

Grade II tumors are defined as being infiltrative gliomas — the tumor cells penetrate into the surrounding normal brain, making a surgical cure more difficult.



Most patients with grade II glioma (oligodendrogliomas, astrocytomas, mixed oligoastrocytomas) are young people who often present with seizures. The median survival varies with the cell type of the tumor. People with oligodendrogliomas have better a prognosis than those with mixed oligoastrocytomas who have better a prognosis than someone with an astrocytoma. Other factors which influence survival include age (younger the better) and performance status (ability to perform tasks of daily living). Due to the infiltrative nature of these tumors, recurrences are relatively common. Depending on the patient, radiation or chemotherapy after surgery is an option.



Most grade II gliomas eventually evolve into more aggressive tumors (grade III or IV) and cannot be cured by surgery and radiation therapy. A practical approach is to remove as much of the abnormal tissue as possible without causing neurologic injury. Research has shown that beginning radiation therapy immediately after diagnosis delays recurrence compared to beginning radiation when there is evidence of tumor growth.



Anaplastic astrocytoma (grade III)

Patients with anaplastic astrocytoma often present with seizures, neurologic deficits, headaches, or changes in mental status. The standard initial treatment is to remove as much of the tumor as possible without worsening neurologic deficits. Radiation therapy has been shown to prolong survival and is a standard component of treatment. In general, median survival ranges from two to three years. There is no proven benefit to adjuvant chemotherapy (supplementing other treatments) for this kind of tumor. Although temozolomide is effective for treating recurrent anaplastic astrocytoma, its role as an adjuvant to radiation therapy has not tested.



Glioblastoma multiforme (Grade IV)

Glioblastoma multiforme is the most common and most malignant primary brain tumor.

Treatment...

Treatment of gliomas is a team process at Mayo Clinic. Specialists from the brain tumor treatment team work together to provide the high-quality, integrated model of care for which Mayo Clinic is known. A neurologist who has expertise and additional training in neuro-oncology usually serves as the primary physician, who helps to coordinate overall care with a team consisting of neurosurgery, medical oncology, radiation oncology, neuropathology and neuroradiology specialists.

New glioma treatments are developed continually, so several options may be available for patients. The pros and cons of each option are discussed in detail during treatment planning. Mayo Clinic's goal is to improve both the duration and quality of survival. Every effort is made to tailor the treatment program to the needs of each patient and family.

Surgery


Surgery is the initial therapy for nearly all patients with gliomas. It can cure most benign gliomas, as well as meningiomas. The goal of surgery is to remove as much of the glioma as possible while minimizing damage to healthy tissue.
Some gliomas can be removed completely; others can be removed only partially or not at all. Partial removal helps relieve symptoms by reducing pressure on the brain and reducing the size of the glioma to be treated by radiation or chemotherapy.
After the glioma has been removed, Mayo Clinic pathologists immediately evaluate the tissue and report results directly to the surgeon in the operating room. Direct, face-to-face contact with the pathologist during the surgery allows the surgeon to verify that the glioma has been fully removed and may reduce the need for an additional operation.

Radiation Therapy


Radiation Therapy is an essential component of treatment for many patients with gliomas. It can be curative some patients and prolongs survival for most.
The traditional form of radiation therapy, referred to as fractionated radiation, delivers radiation in small doses (fractions). Typically, patients are treated once daily, five times per week, for a total of five to six weeks. Even after the tumor visible on the CT or MRI scan is removed, radiation is often used to treat the margin of brain around the surgical cavity, going after the microscopic tumor cells that have infiltrated the area from the original mass.

External Beam Radiation


This traditional form of radiation therapy delivers radiation from outside the body. The radiation usually involves treatments five days a week. The length of treatment time depends on the type of glioma. External beam radiation is less precise than Fractionalized Stereotactic Radiotherapy, but allows a wider area of tissue around the glioma to be treated.

Chemotherapy


Chemotherapy is an important part of the care of glioma patients. For patients with glioblastoma (Grade 4 astroccytoma), the most rapidly growing and aggressive glioma, the addition of chemotherapy to the radiation has been shown to significantly extend a patient's lifespan. Current research is focused on the development and evaluation of new drugs to use with radiation for a newly diagnosed tumor, as well as for recurrent gliomas.
Mayo Clinic is a research leader in treating brain tumors with chemotherapy, and patients may be offered an opportunity to participate in trials that are appropriate for their situation.

Vaccine and Viral Therapies


Modulation of the patient's immune system to attempt to control the glioma by immunization or induction of immune cells and the use of modified viruses to attack the tumor are other treatment approaches studied at Mayo Clinic. Clinical trials with vaccines and virus therapy are underway.