1. What is a brain tumor, what are the characteristics of benign and malignant brain tumors?
We call any kind of tumor that develops in the cranial cavity and settles in the brain, multiplies abnormally, and exerts pressure on the brain. These tumors can be benign or malignant. Benign brain tumors do not contain cancerous cells, usually grow slowly and insidiously, and do not invade the surrounding tissues. However, they can cause serious health problems by pressing on sensitive areas of the brain. Benign tumors can sometimes be life-threatening, depending on their location. In very rare cases, a benign brain tumor can turn into a malignant tumor. Malignant tumors contain cancerous cells. More seriously and often, they threaten life, grow rapidly and invade the surrounding healthy brain tissue. Malignant tumors can originate from the brain itself, or it can be the result of the spread of cancerous cells from distant organs to the brain. Cancer that has spread to the brain is called metastasis.
2. What are primary (primary) and secondary (secondary) brain tumors?
Primary brain tumors are tumors originating from the brain itself. They are named according to their cell types and locations. The most common primary brain tumor is gliomas. These start from the cells we call glial cells and there are many types. For example, ‘astrocytomas’ proliferate from cells called astrocytes. They occur in the brain in adults, and often in the brain stem and cerebellum in children. We grade these tumors according to their type. As low grade grade1 and 2, high grade as grade 3 and 4. It is known as grade 3 anaplastic grade 4 glioblastoma multiforme. Another type of tumor is what we call ependymoma. These tumors are more common in the cerebellum and spinal cord. It is common in children and young adults. Another type of tumor is oligodendrogliomas. These usually settle in the brain. It is most common in middle-aged adults. There are also tumors that do not originate from glial cells. Medulloblastoma usually arises in the cerebellum and is the most common brain tumor in children. Another type of tumor is meningiomas. These are benign tumors, they usually grow slowly. Another type of tumor called schwannoma arises from the auditory nerve, another name is acoustic neuroma, it occurs with balance and hearing problems in adults. There are also pituitary adenomas, craniopharyngiomas, germ cell tumors, pineal region tumors, depending on the location and type.
Secondary brain tumors spread to the brain from elsewhere in the body. In particular, we see the spread of lung and breast cancers to the brain frequently.
3. What is the incidence of brain tumors?
The incidence of brain tumors is between 4 and 5 per 100 thousand people. Primary brain tumors account for 3 percent of cancer-related deaths. However, in disorders caused by the involvement of the nervous system by other types of cancer, approximately 10 times this rate of death occurs. It is more common in men than women. About 24000 primary brain tumors are diagnosed each year in a population of 300 million in the USA. It is said to be parallel to this in our country. After leukemia and lymphoma, primary brain tumors are the most common primary brain tumors in children. Brain tumors constitute 20-25 percent of malignant tumors in childhood. The most common primary brain tumors are gliomas, followed by meningiomas.
4. Who is at risk for a brain tumor?
The exact cause of brain tumors is unknown. However, risk factors come to the fore in some people. Being a man, race, age, family history, radiation, formaldehyde, vinyl chloride, acrylonitrile are among these. It is more common especially in men than in women. However, benign meningiomas are more common in women. It is more common in the white race. It is most common in the age of 60-70 years, it is the second most common type of cancer in children. Although it is not known exactly, it is more likely to occur in those with a family history of brain tumors. Some tumors are embryonal and congenital. The risk is high in radiation and industrial workers. The risk of people exposed to some chemicals is high. The risk is high, especially due to vinyl chloride used in plastic production and acrylonitrile used in textile production. The relationship between mobile phone and brain tumor is still being investigated. No clear results were obtained in the studies. Again, the relationship is not clear in people who have had head trauma.
5. What are the symptoms of a brain tumor?
Symptoms of a brain tumor vary according to the size, location, and type of tumor. The most common general symptoms in a tumor that suppresses the brain are headache, nausea and vomiting, changes in speech, vision and hearing, gait disturbance, instability, personality and ability changes, concentration disorder, mood disorder, problems with memory, seizures and convulsions, arm and twitching, numbness and weakness in the legs. Headache is the most common and earliest symptom, it is usually severe. It can be continuous, and rarely comes in seizures in the initial phase. In some people, it progresses in the form of mild seizures that become more and more severe. It is usually earlier and more severe in cerebellum tumors than in other regions. Symptoms in these tumors usually begin with a sudden and very severe headache. Vomiting due to increased intracranial pressure is not related to meals; Nausea is not seen, it is in the form of spitting. Dizziness is seen in cerebellum and auditory nerve tumors stimulated by head movements. Complaints such as temporary unconsciousness, fainting and sudden worsening observed in tumors of other regions may be mistakenly defined as dizziness by the patient.
6.How are brain tumors diagnosed?
First of all, a good physical and neurological examination should be done for the patient who applies to the doctor with a certain complaint. In the neurological examination, the patient’s muscle strength, coordination, reflexes, nerve and sensory examinations should be performed. After these examinations, imaging methods are applied. Some tumors can be seen on a normal x-ray. However, today, with the technological developments, diagnostic methods have also increased. With CT (computerized brain tomography), information is obtained about the size of the tumor, especially by administering medication. Another diagnostic method is MRI (magnetic resonance imaging). With MRI, information can be obtained about the location of the tumor, its nature, peripheral edema, whether it is benign or not. In some tumors, angiography can also be performed to see the relationship with the vessels and for differential diagnosis. A biopsy of a suspected brain tumor is performed to examine the tissue sample and the diagnosis can be confirmed. The tissue sample taken should be in sufficient quantity and suitable for reaching the diagnosis. The pathologist examines the material under the microscope. Biopsy is the most accurate method of diagnosing brain tumors. A biopsy is the removal of a millimeter-sized piece by inserting a needle through a hole in the skull. Various methods have been developed for performing a biopsy. Stereotactic biopsy is performed with an imaging device accompanied by CT MRI.
7. What are the treatment methods in brain tumors?
Today, there are various treatment options for brain tumors. Depending on the type and stage of the tumor, patients can be treated with surgery, radiotherapy or chemotherapy. In some patients, all of these treatments are done together. Treatment is also needed at any stage of the disease to alleviate the side effects of treatment, reduce emotional problems, and control cancer pain and other symptoms. This type of treatment is called supportive therapy or palliative care. Brain tumors must be treated by consulting more than one doctor and department. In this approach, which we call the multidisciplinary approach, neurosurgeons, medical oncologists, radiation oncologists, pathologists, and radiology physicians should consider the patient as a whole. Today, oncology councils are formed for this disease group and different opinions are combined and the most appropriate decision is made for the patient. However, all treatment attempts applied to date in malignant gliomas have been inconclusive and they are considered fatal.
Surgery: The aim of this treatment method is to remove the tumor. Surgery is performed under general anaesthesia. With the method we call microsurgery, we perform these surgeries with a special microscope device, using the bone removal method according to the location of the tumor, which we call craniotomy. The aim of the microsurgical method is to damage the normal brain tissue as little as possible and to remove the tumor as much as possible. Although sometimes it is not possible to remove all of the tumor depending on the location and type of the tumor, removing a part of the tumor also facilitates additional treatments and minimizes its recurrence. Especially in brain tumors that are difficult to reach and not fully diagnosed, the neuronavigation process can detect the location of the tumor without damaging the surrounding brain tissue, and can be removed and a pathological diagnosis can be made. Today, surgery can be performed on any region, including the brain stem. However, surgical intervention may not be possible depending on the location of some tumor types. Radiotherapy and chemotherapy come into play when it is necessary not to damage the normal brain tissue and pose a life-threatening risk.
Radiotherapy (radiation therapy): The aim is to kill tumor cells by giving high doses of radiation. Radiation uses x rays, gamma rays or protons. Giving high doses of radiation without permanently damaging the healthy brain tissue is a very difficult technical problem today. According to our current knowledge, the radiation resistance of the nervous tissue is unsuitable for the application method by increasing the total dose in parts. One of the possible options that can be applied under these conditions is irradiation with hyperbaric oxygen therapy, and the other is the administration of radiation desensitizing agents together with radiation. Radiation therapy can be done after surgical treatment or can be done directly in patients who cannot have surgery. Radiotherapy varies according to the size of the tumor and the age of the patient. Necessary measures to prevent damage to healthy brain tissue are fractionation, hyperfraction stereotactic radiotherapy, three-dimensional conformal radiotherapy, proton beam radiation therapy.
Chemotherapy: It is the use of drugs to kill cancerous cells. Medications can be given orally or by injection. A hospital stay is rarely required during chemotherapy. Chemotherapy may be required after surgery and radiotherapy in adults.
Supportive care therapy: At any stage of the disease, patients with brain tumors receive supportive care therapy to reduce their problems, live comfortably and increase their quality of life. Some of these are steroids as drugs, seizure convulsion drugs, which we call anticonvulsants. Also, since some tumors can cause paralysis, physiotherapists try to restore patients’ strength and balance. Speech therapists, occupational therapists help meet the needs of the patient.
8.What are the side effects of the treatment?
Undesirable side effects may occur, since damage may occur in healthy tissues after surgery. These side effects vary according to the location of the tumor and its type. Side effects may not be the same for every person. Eliminating the resulting side effects also requires a separate treatment. The most common condition is headache. It may take a few days. It is controlled with medication. Fatigue can be fatigue. Steroid drugs are given to reduce edema in the brain after surgery. Convulsions may develop. These conditions are also controlled with medication. Signs of infection may occur. It is also possible to treat with medication. Sometimes, inability to speak and weakness may develop after surgery. In this case, physical therapy, speech therapy or occupational therapy may be required. Nausea, weakness, fatigue, temporary hair loss, skin dryness and spots may occur most frequently after radiotherapy. In these cases, necessary drug treatments are given. If given together with chemotherapy, the side effects may be worse. Especially in children, radiation can damage the pituitary gland and other areas of the brain. Therefore, chemotherapy is used more than radiotherapy in children.
9. What is the post-treatment process in patients with brain tumors?
Regular follow-up is important in patients with brain tumors. Regular neurological examination should be performed and CT and MRI checks should be performed at regular intervals. Living with this disease is not easy. Some patients need support in coping with the emotionality of their illness. Patient families should be made aware and sharing should be increased. Although the prognosis of brain tumors is often poor and ends in death, the expected life expectancy is not always clear. In malignant gliomas, despite the advances in surgery and radiotherapy, the use of new chemotherapeutic drugs and combined treatments, the end of the process is bad; these cases end in death within two years at the latest. Surgical treatment alone provides a life expectancy of 3-6 months, the addition of radiation therapy prolongs the period for another 3-4 months; Triple therapy with the addition of drug therapy to these two treatments can prolong life expectancy by 12 months or more. In cases of malignant glioma, only 20 percent of patients at the end of the first year; At the end of the 24th month, only 10 percent survive. It is hoped that better results will be obtained by finding new methods and/or improving existing ones in the future.
