Astrocytoma: Types, Symptoms, Causes And Treatment
“You have a tumor.” This is probably one of the phrases we most fear hearing when we go to the doctor for a check-up or undergo tests for a problem for which we do not know the cause. And it is that Cancer is one of the most feared diseases worldwide, being one of the best known and main causes of death worldwide and one of the main challenges in medicine along with AIDS and dementia.
Among the many locations in which it can appear, the brain is one of the most dangerous, since even a benign, non-cancerous tumor can cause serious effects and even death. Among the different types of existing brain tumors, one of the most common are astrocytomas which we are going to talk about in this article.
We call astrocytoma any neoplasia or tumor formed mainly by astrocytes, one of the main types of glial cells that feed and support neurons. This tumor is therefore a mass of astrocytes that occurs due to abnormal, pathological and uncontrolled growth and proliferation of one of the types of glial tissue present in the nervous system, being one of the main types of brain tumor.
Astrocytomas are tumors whose symptoms can vary enormously depending on the location or locations in which they appear, whether they compress other brain areas, their proliferative capacity or whether they infiltrate other tissues or are self-limiting. However, at a general level it is common to find the existence of headaches, nausea and vomiting, drowsiness and fatigue, altered consciousness and confusion. It is also relatively common for personality and behavioral alterations to appear. Fever and dizziness are also common, as well as unexplained weight changes, perception and language problems and loss of sensitivity and mobility, and even seizures. It is also possible, especially when they occur in children, that they generate malformations and that the craniofacial anatomy is altered, both intracranial and extracranial
This type of tumor can occur, as occurs with other tumors, limited to a specific region or structure or diffusely, with the former having a much better prognosis than the latter. In general, they do not tend to produce metastases to other areas of the body beyond the nervous system, although they do expand within said system.
The diagnosis of these tumors is complex, requiring various procedures to be performed. First of all it is necessary to perform a biopsy of the tumor, which will allow us to take a sample of the brain tumor, currently being performed using stereotaxy. Subsequently, it will be necessary to perform a phenotypic and histological analysis to verify the type of tissue we are talking about, as well as its behavior. Finally, it will be necessary to assess the proliferative capacity, in order to be able to determine its degree and infiltration capacity.
Causes
As with other brain tumors, the causes of astrocytomas are mostly unknown. However, some hereditary disorders can facilitate its appearance, such as neurofibromatosis. Also infection with the Epstein-Barr virus or previous application of radiotherapy due to another tumor seem to be risk factors for developing them.
Classification according to grades
The term astrocytoma, as we have already indicated previously, groups together the set of tumors or neuplasias made up mainly of astrocytes. But Within astrocytomas we can find various classifications and divisions, depending among other criteria on its degree of malignancy and proliferation. In this sense, we can observe the existence of four degrees of severity
Grade I
Grade one astrocytomas are considered all those tumors whose main characteristic is their benignity. The weight of this can cause serious problems and even be fatal or cause disability depending on whether they grow and cause parts of the brain to crush against the skull. These are rare tumors, predominantly childhood, that They have the advantage of having a very high degree of survival and be relatively easy to treat. In many cases, surgical resection is sufficient. An example of tumors of this grade is found in pilocytic astrocytoma.
Grade II
Unlike grade I astrocytomas, grade II astrocytomas are actually cancer, being malignant tumors. Aggressive grade two astrocytomas, much more complex to treat and considered malignant and expansive. They tend to cause epileptic seizures, observing diffuse lesions. Generally this group includes diffuse astrocytomas, among which the most common are fibrillar, gemistocytic and protoplasmic astrocytomas. They are the most common type of low-grade astrocytoma.
Grade III
Grade three astrocytomas result a type of malignant tumor that has a high capacity for proliferation and infiltration to other structures. The best known is anaplastic astrocytoma. It is common that it is the evolution of one of the previous tumors and even evolves into a grade four tumor.
Astrocytomas that are more invasive, aggressive and infiltrative, rapidly expanding to other areas of the brain, are considered grade four. The most typical and well-known astrocytoma with this degree of malignancy is glioblastoma multiforme, being in fact the most common type of brain neoplasm. The prognosis is usually fatal and life expectancy is greatly reduced.
The two most frequent
Below are some of the most common characteristics of some of the two most common and well-known types of astrocytoma.
Glioblastoma multiforme
The most common of all astrocytomas and one of the most common brain tumors (about a quarter of diagnosed brain tumors are glioblastomas) is also the most aggressive and has the worst prognosis. It is a tumor in which the cells are poorly differentiated, which reproduces at high speed and proliferates at the vascular level. generating death and degeneration of other structures due to necrosis Life expectancy does not usually exceed one year and three months. It can be primary, appearing on its own, but generally it is an evolution of one of the lower grade tumors.
Anaplastic astrocytoma
The second of the most well-known and malignant types, we are dealing with a grade III astrocytoma that tends to infiltrate the surrounding tissue without completely destroying it, causing a thickening of the tissue. It usually generates edema around the affected area, although it does not usually generate necrosis. Survival is greater than in glioblastoma, although only around 20% survive more than five years. It has been debated whether there is a hereditary genetic predisposition in some subjects because some hereditary syndromes predispose its appearance.
Treatments
The treatment of a brain tumor such as astrocytomas is something that must be carefully planned, taking into account that we are facing an intervention that can generate alterations in different brain regions beyond that directly affected by the tumor. However, even if secondary alterations occur, the priority must be the integrity
Surgery to perform tumor resection is one of the main treatment modalities for astrocytomas, being the initial treatment to be applied in practically everything and after which other therapies will be applied to eliminate the remains of the tumor. or prevent its expansion. However, Sometimes complete resection will not be possible as occurs in cases in which the tumor is located in the brain stem (since its resection could cause the death of the subject by controlling this area’s vital functions).
This resection is carried out in both low-grade and high-grade tumors, although in the latter it is common for recurrences and infiltrations in other brain areas to occur. This is because even in these cases resection can improve the patient’s mental abilities that were diminished by the pressure of the tumor. Once the maximum possible amount of tumor has been removed, they are usually used radiotherapy and chemotherapy to combat the remains of cancer cells
In the case of radiotherapy, we are dealing with the application of high doses of radiation on cancerous tissues in order to destroy cells and reduce or complete elimination of tumors, and it has been found to be very effective in tumors of a high degree of malignancy. It must be taken into account the need to focus the radiation only on the cancerous area, since if it were used widely, a large number of healthy cells would be excessively destroyed.
Chemotherapy is the application of powerful chemicals and drugs used to combat the tumor, generally through the inhibition of tumor proliferation by applying substances that prevent cell division and DNA repair Among these substances we can find temozolomide, ifosfamide, etoposide, carboplatin or lomustine.
At a psychological level, intervention is also recommended, especially when symptoms and alterations of anxiety and mood occur. Psychoeducation is essential, especially in those cases in which the only possible treatment is only palliative and/or are in a terminal phase. It is also essential to have a safe and reliable space in which to resolve doubts and express feelings and fears without fear of being judged, something common in this type of illness. Likewise, there are therapies such as adjuvant psychological therapy, creative innovation therapy or visualization therapy that can be applied in order to help the subject have a greater perception of control over their illness.
