Astrocytomas - symptoms, treatment, prognosis. The most important information

Astrocytomas are one of the most common tumors located within the nervous system. What exactly are astrocytomas? Astrocytomas, also known as astrocytic tumors, are a group of tumors that develop in the endbrain from astrocytes that build up the glial tissue. Depending on the type, they can develop in areas around the optic nerves, brainstem, spinal cord, and hemispheres of the brain.

Astrocytomas — diagnosis

The basic tests that allow to identify astrocytoma are imaging tests — computed tomography and magnetic resonance imaging. The obtained image makes it possible to recognize not only the location of the astrocytoma tumor, but also its nature, influence on the surrounding tissues and degree of malignancy.

The World Health Organization (WHO) classification of astrocytomas from 2016

Astrocytomas are a heterogeneous group — they can be characterized by a varied histological picture and genetic profile. This is of particular importance in terms of diagnostics. Therefore, in 2016, the World Health Organization introduced changes to the current method of classifying tumors of the central nervous system (World Health Organization Classification of Tumors of the Central Nervous System).

Astrocytoma tumors were divided into four tumor grades. The following astrocytoma grades include:

• GI: Astrocytoma pilocyticum
• GII: Astrocytoma fibrillare, Astrocytoma diffusum, Astrocytoma gemistociticum
• GIII: Astrocytoma anaplasticum
• GIV: Glioblastoma

GI group tumors have the best prognosis. On the other side of the spectrum are GIV neoplasms that have the worst prognosis.

Astrocytomas — types

Astrocytoma pilocyticum — otherwise also known as a spongoma, most often occurs around the optic nerve and within the cerebellar hemispheres. It is a benign astrocytoma (GI grade) — infiltration is extremely rare in this case, and the tumor itself is well-delimited.

Astrocytoma fibrillare — most often occurs in the brain stem, spinal cord and hemispheres of the brain. It is a grade II (GII) malignancy and is characterized by slow growth. It usually occurs in adults.

Aastrocytoma gemistociticum — it is a grade II malignancy. It is believed to have the ability to progress more rapidly to a higher grade cancer than diffuse astrocytoma. It is associated with a worse prognosis.

Astrocytoma diffusum — it is a grade II malignancy. It usually occurs in people around 40 years old and is most common among men. The structure of diffuse astrocytomas consists of highly differentiated cells, which means that its growth is slow. Despite their slow growth rate, these tumors can invade surrounding structures as well as develop into higher-grade tumors.

Astrocytoma anaplasticum — it is a grade III malignancy It usually occurs around age 40 and is most common in men. Survival rate is influenced by such factors as age and genetic mutations in a tumor. The median survival is approximately 3-5 years. Their characteristic feature is cellular atypia and the rapid pace of progression to grade IV — gliomas.

Astrocytomas — treatment

In the case of mild astrocytomas — grade I, complete removal is possible and is usually performed by surgery. The occurrence of grade II astrocytoma tumors is also associated with a high chance of qualifying for the procedure. Although, its infiltrate and diffuse nature may be a contraindication. Regardless of the degree of malignancy, tumor removal is most often associated with the need for postoperative radiotherapy. The aim of performing it is to minimize the risk of cancer recurrence. As part of the treatment of grade III and IV astrocytomas, both surgery and radiotherapy as well as chemotherapy are used. In operative cases, the goal is to remove as much of the tumor as possible in order to reduce the neurological deficit and extend survival time.

Astrocytomas — prognosis

The prognosis for astrocytomas varies depending on their nature and location. When the cancer has entered the brainstem, the survival time is shorter. However, it is longer when the tumor infiltrates the white matter of the hemispheres, the hypothalamus, or the cerebellum. The age of the patient also influences the survival rate — a younger age extends the survival rate. In addition, relapse is associated with the risk of developing the more malignant type of tumor.

More about brain tumors in the article: Brain tumor — causes, symptoms, tests.