Brain metastases arise when individual cells from other cancers in the body settle in the brain. They are often an expression of late disease and can no longer be treated for healing. Most patients die after a few months. Brain metastases cause similar symptoms as brain tumors. Here you can read all important information about brain metastases.
Brain metastases: overview
About 30 percent of the tumors in the brain are brain metastases. This makes them the most common neoplasms in the central nervous system. Brain metastases are secondary tumors of an already existing cancerous tumor in the body. This is called primary tumor or primarius. More than a quarter of patients with a malignant tumor in the body develop subcultures in the brain. Mostly, brain metastases indicate end-stage or at least a very advanced stage of cancer.
But not every solid tumor in the body is scattered in the brain. Why some types of cancer spread in the brain and others do not, has not yet been fully explored. The risk of brain metastases is decreasing in the following tumors:
- Black skin cancer (malignant melanoma)
- Lung cancer (bronchial carcinoma)
- Breast cancer (breast cancer)
- Renal cell carcinoma (kidney cancer)
- Malignant tumors in the digestive tract
- Malignant tumors in the urinary tract
Since many people suffer from lung cancer, it accounts for about half of all brain metastases diagnosed. The second most common cancer identified as a cause of brain metastasis is breast cancer, accounting for about 20 percent, followed by malignant tumors in the digestive tract, black skin cancer, and cancers of the urinary tract and genitals. Sometimes, brain metastases also exist without the primary tumor being found. Then one speaks of a primarius of unknown origin (Cancer of Unknown Primary, CUP syndrome).
How do you develop brain metastases?
From the primary tumor in the body, individual cells or cell groups can detach and pass through the blood vessels or lymph channels to another body region. In the worst case, they can also attach themselves to the brain and grow there – brain metastases arise. Bone cancer and tumors in the ear, nose and throat can also spread directly into the brain (without the blood and lymph).
Brain metastases: solitary, singular, multiple
If the primary tumor has been scattered only once, it is called a solitary metastasis. If there are additional tumor deposits in other organs, the brain metastasis is referred to as singular. In more than half of the patients with brain metastases, only one brain tumor is diagnosed. Multiple brain metastases are present when tumor cells have settled in several places in the brain.
Once cancer cells have reached the central nervous system, they can spread throughout the nervous fluid (cerebrospinal fluid). The cerebrospinal fluid circulates around the brain, individual chambers in the brain and the spinal cord. It usually protects the brain against shocks and injuries. If the cancerous cells spread via the cerebrospinal fluid to the meninges, this is called a meningitis carcinomatosa.
Brain metastases: symptoms
Since retarded tumor cells can grow in different places in the brain, the brain metastasis symptoms are also different. Often headaches, nausea, vomiting or an epileptic seizure are the first signs. In principle, however, all the symptoms that a primary brain tumor can cause can occur.
Brain Tumor – Symptoms
For more information, see the article Brain Tumor Symptoms.
In meningitis carcinomatosa often clog the CSF pathways. This aggravates the danger that the intracranial pressure increases.
In about one in ten cancer patients, according to the German Cancer Society cause brain metastases symptoms before the primary tumor is known. With them, therefore, there are already cases of brain dislocation in the first diagnosis of the cancer.
Brain metastases: treatment
In principle, brain metastases are treated in a similar way as primary brain tumors. With a large diameter of several centimeters, they should be surgically removed. If there are more than three brain metastases, they are usually irradiated. In patients with advanced disease and reduced health, whole-brain radiation is an important form of therapy. In addition, chemotherapy may be used. This medication is used, with which also the Primarius is treated.
You can read more about the individual treatment options in the article Brain Tumor.
Brain metastases: life expectancy
Mostly, brain metastases do not develop until a late stage of cancer. Life expectancy and disease course therefore also depend on the underlying disease. If the causative cancer is treatable well, those affected usually survive longer. In addition, it is considered a good sign if brain metastases occur long after the cancer diagnosis. Younger patients and those with a relatively good overall condition usually also have a longer life expectancy. For multiple brain metastases, the prognosis is usually worse than for a single tumor.
Overall, life expectancy for patients with brain metastases is only three to six months. About ten percent of those affected survive the first twelve months after diagnosis, with only a few patients still living with their disease for several years. With a Meningeosis carcinomatosa the prognosis is even worse. Even therapy can only increase median survival from a few weeks to a few months.
About half of all patients die from their primary tumor disease and not necessarily from the Brain metastases.