Brain Tumors and the Risk of Stroke

Can Brain Tumors Cause Stroke?

Brain Tumors and the Risk of Stroke

An uncommon complication of brain cancer is bleeding within the brain (called an intracranial hemorrhage) which can lead to a hemorrhagic stroke. This is a relatively rare situation but one that is more ly to occur in people over 60 who have certain types of brain cancer or who have undergone radiation treatments to the head or neck.

The symptoms of a stroke caused by an intracerebral hemorrhage are different from a typical stroke. This is because most strokes, known as ischemic strokes, occur suddenly when a blood vessel in the brain is blocked.

Since brain tumors grow slowly, stroke symptoms tend to develop over the course of days, weeks, or months rather than hours or minutes. If the rupture of a vessel in the brain leads to a stroke, it is called a hemorrhagic stroke. The most common symptoms of a hemorrhagic stroke include:

  • A severe headache
  • Double vision
  • Weakness on one side of the body
  • Paralysis or numbness on one side of the body
  • Inability to speak
  • Inability to understand spoken language
  • Difficulty writing or reading
  • Changes in vision or vision loss
  • Seizures or convulsions

Both the amount of bleeding and the location of the hemorrhage will determine whether the symptoms are mild or severe.

Studies suggest that people who develop stroke as a result of a brain tumor are highly vulnerable to a second stroke, usually within 2.2 years.

There are two main types of brain tumors, either one of which can develop bleeding:

  • Primary brain tumors originate within brain tissue. Examples include pituitary tumors, gliomas (generally fast-growing), and meningiomas (generally slow-growing and benign).
  • Metastatic brain tumors start in one area of the body (such as the lungs, breast, or kidneys) and spread to another part of the body.

Bleeding from a primary brain tumor is a relatively rare event. A brain tumor's tendency to bleed depends on the tumor's characteristics. For instance, meningiomas (which develop in the membrane surrounding the brain and spinal cord) rarely cause bleeding.

Although brain metastases from lung or breast cancer are less ly to bleed, those associated with melanoma are highly vulnerable to bleeding. Studies suggest that up to 50% of intracranial hemorrhages caused by metastasis are related to melanoma.

By contrast, gliomas (which develops in sticky cells surrounding nerve cells) are more vulnerable to bleeding, in part because they are fast-growing. Pituitary tumors are also prone to bleeding.

According to a 2017 study in the journal Stroke, 72% of strokes caused by a brain tumor are the result of a glioma. Prior radiation to the head and neck is also a major risk factor, occurring in no less than 71% of cases.

Bleeding from a brain tumor cancer can usually be diagnosed with computed tomography (CT). With a CT scan of the brain, the area of bleeding typically appears as a bright white area, in contrast to the grayish appearance of the normal brain tissue. In addition, the blood in the brain is typically surrounded by a darker area, which represents brain swelling.

Most injuries to the brain, including strokes and brain tumors, cause swelling. The shape and size of the swelling help doctors determine whether the bleeding is caused by a brain tumor or another condition (such as head trauma).

If there is any suspicion that a brain tumor is involved, the next test will be to order a magnetic resonance imaging (MRI) scan of the brain along with an injection of a contrast agent known as gadolinium. Gadolinium helps delineate areas of healthy brain tissue, blood, and cancerous tissue.

It is not uncommon for intracranial bleeding caused by a glioma to be misdiagnosed as a hypertensive crisis. Unless an MRI with a contrast agent is ordered, the glioma may be entirely missed and allowed to grow unchecked.

The treatment of intracranial bleeding depends on the symptoms and the volume of blood involved. The standard treatment is to remove the blood and tumor at the same time. However, if the volume of blood is small, and the symptoms are mild, surgery may not be needed.

If it is safe to delay surgery, other tests will be performed to help confirm the location of the brain tumor and whether it is primary or metastatic). An oncologist can then decide what other cancer treatments are needed, such as radiation and chemotherapy.

Generally speaking, the prognosis is poor if a stroke occurs as a result of brain cancer. Although 85% of people can achieve disease-free survival for a year, recurrence will typically occur before the second year. All told, the median survival time is 11.7 months from the time of surgery.

With that said, survival times can increase to five years and even more if the stroke was mild and the cancer is diagnosed in an earlier stage.

If you or a loved one has had a brain hemorrhage caused by a tumor, you will need to follow very closely with a medical team, including an oncologist, a neurologist, and a neurosurgeon. While recovery may be slow and exhausting, both physically and mentally, with strong support from loved ones and your healthcare team, you can get through it.

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  1. Burch JE, Parikh NS, Kamel H, DeAngelis LM, Navi BB. Abstract TMP51: Ischemic Stroke in Patient with Primary Brain Tumors: Mechanisms and Risk of Recurrence. Stroke. 2017;48:ATMP51.

  2. Yoo H, Jung E, Gwak HS, Shin SH, Lee SH. Surgical outcomes of hemorrhagic metastatic brain tumors. Cancer Res Treat. 2011;43(2):102-7. doi:10.4143/crt.2011.43.2.102

  3. Choi G, Park DH, Kang SH, Chung YG. Glioma mimicking a hypertensive intracerebral hemorrhage. J Korean Neurosurg Soc. 2013;54(2):125-7. doi:10.3340/jkns.2013.54.2.125


Unlocking Mysteries Of Brain Cancer, Stroke

Brain Tumors and the Risk of Stroke

New studies at the University of Adelaide will delve into some of the crucial issues surrounding death by brain tumours and stroke.

The research, to be conducted in the joint University of Adelaide/IMVS Centre for Neurological Diseases, will aim to find links between chemical signals in the brain and the reasons why brain tumours or strokes become fatal.

“There are still many mysteries around how the brain works, and this new research will help to unlock key elements we believe are involved in two separate but equally debilitating conditions,” says Professor Robert Vink, Head of the University's School of Medical Sciences and NRF Chair of Neurosurgical Research.

Brain tumours account for approximately 2% of all cancer deaths. However, a much greater problem is the spread of cancer, with secondary tumours developing within the central nervous system. This accounts for almost 10 times as many deaths as primary brain tumours.

For the first time, the Centre for Neurological Diseases will begin studies of brain tumours focusing on two specific research questions. The first is concerned with the oedema (swelling) caused in neural tissue by tumours, which plays a major role in patient mortality.

“We know that the cerebral blood vessels in the vicinity of the tumour become `leaky', and this is what underlies the development of the swelling. However, the mechanism that causes this change in vascular permeability is unknown,” Professor Vink says.

“From our research into traumatic brain injury and stroke, we believe that neuropeptides (chains of amino acids in the neural tissue) may play a key role in changing the permeability of the blood-brain barrier. This could also offer a novel therapeutic approach to managing the oedema caused by tumours, and therefore play an important part in helping to save patients' lives,” he says.

The second research question focuses on how cancerous cells enter the central nervous system, because the blood-brain barrier should normally prevent any cells – including cancer cells – from infiltrating the brain.

“We will examine whether neuropeptides play any role in enabling these cancerous cells to cross the blood-brain barrier and facilitate secondary tumour development,” Professor Vink says.

This year, the Centre for Neurological Diseases has also begun two new research projects investigating the role that a specific neuropeptide – known as substance P – can play in helping to prevent injury and death in victims of stroke. Substance P is a neurotransmitter and modulator that appears to be connected with brain haemorrhage.

“These haemorrhages exacerbate the injury caused by stroke or brain trauma and are known to significantly increase mortality and worsen outcome in survivors. However, the mechanisms associated with how this exacerbation occurs are still unknown,” Professor Vink says.

“Our lab has evidence to suggest that substance P may play a major role in the injury process, and the use of antagonists which act to block substance P may therefore be highly beneficial in improving a patient's outcome.”

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Materials provided by University of Adelaide. Note: Content may be edited for style and length.


Risk Factors for Brain and Spinal Cord Tumors in Children

Brain Tumors and the Risk of Stroke

A risk factor is anything that affects a person’s chance of getting a disease such as a brain or spinal cord tumor. Different types of cancer have different risk factors.

Lifestyle-related risk factors such as diet, body weight, physical activity, and tobacco use play a major role in many adult cancers. But these factors usually take many years to influence cancer risk, and they are not thought to play much of a role in childhood cancers, including brain tumors.

Very few risk factors have been found for brain and spinal cord tumors. There is no clear cause for most of these tumors.

Radiation exposure

The only well-established environmental risk factor for brain tumors is radiation exposure to the head, which most often comes from the treatment of other conditions.

For example, before the risks of radiation were well known (more than 50 years ago), children with ringworm of the scalp (a fungal infection) often received low-dose radiation therapy. This was later found to increase their risk of some types of brain tumors as they got older.

Today, most radiation-induced brain tumors are caused by radiation given to the head to treat other cancers, such as leukemia. These brain tumors usually develop around 10 to 15 years after getting radiation therapy.

Radiation-induced tumors are still fairly rare, but because of the increased risk (as well as the other possible side effects), radiation therapy is only given to the head after carefully weighing the possible benefits and risks. For most patients with cancer in or near the brain, the benefits of getting radiation therapy as part of their treatment far outweigh the small risk of developing a brain tumor years later.

The possible risk from fetal or childhood exposure to imaging tests that use radiation, such as x-rays or CT scans, is not known for sure.

These tests use much lower levels of radiation than those used in radiation treatments, so if there is any increase in risk, it is ly to be very small.

But to be safe, most doctors recommend that pregnant women and children not get these tests unless they are absolutely needed.

Inherited and genetic conditions

Rarely, children have inherited abnormal genes from a parent that put them at increased risk for certain types of brain tumors. In other cases, these abnormal genes are not inherited but occur as a result of changes (mutations) in the gene before birth.

People with inherited tumor syndromes often have many tumors that start when they are young. Some of the better known syndromes include:

Neurofibromatosis type 1 (von Recklinghausen disease)

This is the most common syndrome linked to brain or spinal cord tumors. It is often inherited from a parent, but it can also start in some children whose parents don’t have it.

Children with this syndrome may have optic gliomas or other gliomas of the brain or spinal cord, or neurofibromas (benign tumors of peripheral nerves).

Changes in the NF1 gene cause this disorder.

Neurofibromatosis type 2

This condition is less common than von Recklinghausen disease. It can also either be inherited or may start in children without a family history.

It is associated with cranial or spinal nerve schwannomas, especially vestibular schwannomas (acoustic neuromas), which almost always occur on both sides of the head.

It is also linked to an increased risk of meningiomas, as well as spinal cord gliomas or ependymomas. Changes in the NF2 gene are nearly always responsible for neurofibromatosis type 2.

Tuberous sclerosis

Children with this condition may develop subependymal giant cell astrocytomas (SEGAs), as well as other benign tumors of the brain, skin, heart, kidneys, or other organs. This condition is caused by changes in either the TSC1 or the TSC2 gene.

Von Hippel-Lindau disease

Children with this disease tend to develop blood vessel tumors (hemangioblastomas) of the cerebellum, spinal cord, or retina, as well as tumors in the kidney, pancreas, and some other parts of the body. It is caused by changes in the VHL gene.

Li-Fraumeni syndrome

People with this syndrome have an increased risk of gliomas, as well as breast cancer, soft tissue sarcomas, leukemia, and some other types of cancer. It is caused by changes in the TP53 gene.

Other syndromes

Other inherited conditions linked with increased risks of certain types of brain and spinal cord tumors include:

  • Gorlin syndrome (basal cell nevus syndrome)
  • Turcot syndrome
  • Cowden syndrome
  • Hereditary retinoblastoma
  • Rubinstein-Taybi syndrome

Some families may have genetic disorders that are not well recognized or that could even be unique to a particular family.

Cell phone use

Cell phones give off radiofrequency (RF) rays, a form of electromagnetic energy on the spectrum between FM radio waves and those used in microwave ovens, radar, and satellite stations.

Cell phones do not give off ionizing radiation, the type that can cause cancer by damaging the DNA inside cells.

Still, there have been concerns that the phones, whose antennae are built-in and therefore are placed close to the head when being used, might somehow raise the risk of brain tumors.

Some studies have suggested a possible increased risk of brain tumors or of vestibular schwannomas (acoustic neuromas) in adults with cell phone use, but most of the larger studies done so far have not found an increased risk, either overall or among specific types of tumors.

Still, there are very few studies of long-term use (10 years or more), and cell phones haven’t been around long enough to determine the possible risks of lifetime use. The same is true of any possible higher risks in children, who are increasingly using cell phones.

Cell phone technology also continues to change, and it’s not clear how this might affect any risk.

These risks are being studied, but it will ly be many years before firm conclusions can be made. In the meantime, for people concerned about the possible risks, there are ways to lower their (and their children’s) exposure, such as using the phone's speaker or an earpiece to move the phone itself away from the head when used. For more information, see Cellular Phones.

Other factors

Exposure to aspartame (a sugar substitute), exposure to electromagnetic fields from power lines and other sources, and infection with certain viruses have been suggested as possible risk factors, but most researchers agree that there is no convincing evidence to link these factors to brain tumors. Research on these and other potential risk factors continues.


Radiotherapy Exposure in Cancer Patients and Subsequent Risk of Stroke: A Systematic Review and Meta-Analysis

Brain Tumors and the Risk of Stroke

World-wide arterial disease (including stroke) and cancer are the leading causes of death [see World Health Organization website: (1–4)].

Concerns regarding the risk of subsequent stroke after radiotherapy for cancer is rising as evidence grows regarding how ionizing radiation from radiotherapy damages the heart and cerebral vessels (5).

However, it remains unclear whether radiotherapy increases subsequent stroke risk in cancer patients compared to cancer patients given other or no specific treatment. Some studies have indicated an increased stroke rate with radiotherapy (6) and others have not (7, 8).

Possible reasons why the previous studies have varied with respect to stroke risk with radiotherapy include confounding factors. For instance, radiation dose and age at first exposure may affect stroke risk.

Stroke risk may be different according to countries or region or may vary according to different cancer types. Therefore, we conducted a meta-analysis of subsequent stroke rate in cancer patients according to whether or not they received radiotherapy.

Further, we performed meta-analyses according to cancer type, baseline patient age and region where the radiotherapy was given.


This was a meta-analysis of radiotherapy cancer patients vs. non-radiotherapy cancer patients and by subgroups according cancer type, baseline patient age, and region where the treatment was given.

Literatures published from January 1990 to November 2017 were considered. Stroke incidence was compared between cancer patients given any radiotherapy exposure and those not given any radiotherapy exposure. Baseline patient age was divided into 4 ranges, 60 years.

We also collected information on radiotherapy dose in each eligible study.

Inclusion Criteria

Studies were included in the meta-analysis if they: evaluated radiotherapy-treated cancer patients, including any type of cancer patients; included a control group who received non-radiotherapy treatments such as surgery or chemotherapy; utilized any dose and radiation type involving radionuclide decay (e.g., gamma rays) or machine-produced beams (e.g.

, X-rays and electron beams); the exposure of interest was radiotherapy for cancer patients, the outcome was stroke, and the studies reported relative risk (RR) or hazards ratio (HR) values with 95% CIs. RR is a measurement of relative differences. An average annual rate of cancer in radiotherapy and non-radiotherapy patients was also calculated.

We included case-control, cohort studies, and randomized trials. Only English language studies were included. We included studies with any definition of stroke, including due to cerebral ischemia or hemorrhage, with or without systematic brain imaging and no matter the duration of the neurological deficit (< or >24 h).

Only the first stroke/patient after radiotherapy was used in the analyses.

Exclusion Criteria

Studies were excluded from the meta-analysis if they did not involve a cohort of cancer patients or did not discuss radiotherapy treatments. Publication types comprising letters, correspondence articles, case reports, and conference abstracts were also excluded.

Search Strategy

Two independent staff members searched academic databases for records dating from January 1990 to November 2017. Electronic databases were used: PubMed, SpringerLink, Embase, Cochrane Library, Elsevier/ScienceDirect, Medline, Orbis, and Web of Science.

The following search terms were used: (“stroke” [MeSH Terms] OR “stroke” [All Fields]) AND (“neoplasms” [MeSH Terms] OR “neoplasms” [All Fields] OR “cancer” [All Fields]) AND (“cohort studies” [MeSH Terms] OR (“cohort” [All Fields] AND “studies” [All Fields]) OR (“cohort studies” [All Fields] OR “cohort” [All Fields]) OR (“ionizing” [All Fields]) OR (“radiation” [All Fields]) OR “radiotherapy” [All Fields]). Article references were examined for additional studies that may have been missed in the initial search.

Data Collection

Two independent staff members collected the relevant data from each study, including: first author name, year of publication, publication country, cohort follow-up duration, number of participants, baseline age, number of stroke cases, range of radiation dose (highest, lowest, fractional, and median and/or average total dose), adjusted and unadjusted RR (95% CI) for stroke and confounders. Adjusted RR was used in the analyses when available. Unadjusted RR was used in the analyses only when adjusted RR was not published. When a RR for a particular cancer subtype was not published, we used the RR from the whole sample of cancer patients that included patients with that particular cancer subtype, according to whether or not they were given radiotherapy. Study eligibility was confirmed when both reviewers reached consensus on inclusion (Table 1). If any required information was not available in the published article, the authors were contacted (at the email address provided in the article) for additional information.

Table 1. Characteristics of included studies.

RR (95% CI) was the comparator for this meta-analysis and HR (95% CI) was considered equivalent to RR. STATA (version 12.0) was used to conduct the meta-analysis (see online available:

Subgroup meta-analyses were done according to a particular variable (such as cancer type) when there were at least two studies published which provided compatible data with respect to that variable. Statistical heterogeneity was calculated using the I2 test, and the extent of inconsistency was assessed using the I2 statistic.

In general, an I2 value ≥50% was considered as evidence of heterogeneity, and a random-effects model was selected for the meta-analysis. An I2 value


Cranial Irradiation Increases Risk of Stroke in Pediatric Brain Tumor Survivors

Brain Tumors and the Risk of Stroke

The purposes of this study were to determine the incidence of neurovascular events as late complications in pediatric patients with brain tumor and to evaluate radiation as a risk factor.


Patients were ascertained using the tumor database of a pediatric tertiary care center.

Included patients had a primary brain tumor, age birth to 21 years, initial treatment January 1, 1993, to December 31, 2002, and at least 2 visits with neuro-oncology.

Radiation exposure included: whole brain, whole brain plus a focal boost, or focal brain. The primary outcome was stroke or transient ischemic attack.


Of 431 subjects, 14 had 19 events of stroke or transient ischemic attack over a median follow-up of 6.3 years. The incidence rate was 548/100 000 person-years. Overall, 61.5% of subjects received radiation, including 13 of 14 subjects with events.

Median time from first radiation to first event was 4.9 years. The stroke/transient ischemic attack hazard ratio for any brain irradiation was 8.0 (95% CI, 1.05–62; P=0.045); for the circle of Willis, radiation was 9.0 (95% CI, 1.2–70; P=0.

035); and for focal noncircle of Willis, radiation was 3.4 (95% CI, 0.21–55; P=0.38).


The incidence of neurovascular events in this population is 100-fold higher than in the general pediatric population and cranial irradiation is an important risk factor. By defining the incidence of this late effect, physicians are better able to counsel parents regarding treatment, monitor patients at risk, and target a population for primary stroke prevention in future studies.

Radiotherapy, an effective therapeutic modality for the treatment of many pediatric brain tumors, poses significant risks, particularly to the developing brain.

1–3 Cranial irradiation causes late toxicities including neuroendocrine perturbations,4 cognitive deficits,1,2 cavernous malformations,5 small-vessel occlusive disease,1,6–8 vasculopathy, and stroke.

6,9–11 The population at risk for these complications continues to grow, because brain tumors are the most common solid tumor of childhood and length of survival is increasing (5-year survival of 72%).12 With improved long-term survival, understanding the late effects of these treatments becomes paramount.

Cranial irradiation-induced late vasculopathy is well documented in the literature with 47 case reports10,13–19 over the past 30 years and 6 case series/cohort studies.6,20–24 Few studies have determined the incidence, interval to symptoms, or risk factors compared with a control group.

The largest cohort study, from Bowers et al,21 estimated the incidence and relative risk of stroke compared with sibling control subjects in brain tumor survivors (rate, 267.6/100 000; relative risk, 29).

Although this was a landmark study, it did not differentiate between perioperative and late stroke and relied on self-report of stroke.

Brain tumor survivors are at risk for stroke mimics (including migraine, seizure, postictal paralysis, acute demyelinating encephalomyelitis, radiation necrosis, etc)25; thus, estimates self-reports may inaccurately estimate incidence in this group.

In contrast, Ullrich et al22 used MRI to investigate vasculopathy incidence in children with primary brain tumors treated with radiation. Because all subjects received radiation, it was not possible to investigate radiation as a risk factor. Two cohort studies reported the physician-confirmed stroke incidence in both irradiated and nonirradiated brain tumor survivors.

23,24 Defining the true incidence of stroke in these cohorts may have been hampered by a short follow-up duration (mean, 4.

6 years), the inclusion of subjects withneurofibromatosis type 1 who have a known increased risk of spontaneous and radiation-induced neurovascular disease and stroke, and using both ischemic and hemorrhagic strokes as outcome measures despite their distinctive pathogeneses.

The primary aim of this study was to determine the incidence of physician-diagnosed stroke or transient ischemic attack (TIA) as a late complication in pediatric patients with brain tumor at a tertiary care center.

The secondary aim was to evaluate cranial irradiation as a risk factor for stroke or TIA; we hypothesized that children receiving brain radiation have a higher risk of neurovascular events than nonirradiated patients with brain tumor and that radiation to the circle of Willis confers the highest risk.

Brain Tumor – Risk Factors

Brain Tumors and the Risk of Stroke

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ON THIS PAGE: You will find out more about the factors that increase the chance of developing a brain tumor. Use the menu to see other pages.

A risk factor is anything that increases a person’s chance of developing a brain tumor. Although risk factors often influence the development of a brain tumor, most do not directly cause a brain tumor.

Some people with several risk factors never develop a brain tumor, while others with no known risk factors do. Knowing your risk factors and talking about them with your doctor may help you make more informed decisions.

But, at this time, there are no known ways to prevent a brain tumor through lifestyle changes.

Most of the time, the cause of a brain tumor is unknown, but the following factors may raise a person’s risk of developing a brain tumor:

  • Age. Brain tumors are more common in children and older adults, although people of any age can develop a brain tumor.
  • Gender. In general, men are more ly than women to develop a brain tumor. However, some specific types of brain tumors, such as meningioma, are more common in women.
  • Home and work exposures. Exposure to solvents, pesticides, oil products, rubber, or vinyl chloride may increase the risk of developing a brain tumor. However, there is not yet scientific evidence that supports this possible link.
  • Family history. About 5% of brain tumors may be linked to hereditary genetic factors or conditions, including Li-Fraumeni syndrome, neurofibromatosis, nevoid basal cell carcinoma syndrome, tuberous sclerosis, Turcot syndrome, and von Hippel-Lindau disease. Scientists have also found “clusters” of brain tumors within some families without a link to these known hereditary conditions. Studies are underway to try to find a cause for these clusters.
  • Exposure to infections, viruses, and allergens. Infection with the EpsteinBarr virus (EBV) increases the risk of CNS lymphoma. EBV is more commonly known as the virus that causes mononucleosis or “mono”. In other research, high levels of a common virus called cytomegalovirus (CMV) have been found in brain tumor tissue. The meaning of this finding is being researched. Several types of other viruses have been shown to cause brain tumors in research on animals. More data are needed to find out if exposure to infections, other viruses, or allergens increase the risk of a brain tumor in people. Of note, studies have shown that patients with a history of allergies or skin conditions have a lower risk of glioma.
  • Electromagnetic fields. Most studies evaluating the role of electromagnetic fields, such as energy from power lines or from cell phone use, show no link to an increased risk of developing a brain tumor in adults. Because of conflicting information regarding risk in children, the World Health Organization (WHO) recommends limiting cell phone use and promotes the use of a handsfree headset for both adults and children.
  • Race andethnicity. In the United States, white people are more ly to develop gliomas but less ly to develop meningioma than black people. Also, people from northern Europe are more than twice as ly to develop a brain tumor as people in Japan.
  • Ionizing radiation. Previous treatment to the brain or head with ionizing radiation, including xrays, has been shown to be a risk factor for a brain tumor.
  • Head injury and seizures. Serious head trauma has long been studied for its relationship to brain tumors. Some studies have shown a link between head trauma and meningioma, but not between head trauma and glioma. A history of seizures has also been linked with brain tumors, but because a brain tumor can cause seizures, it is not known if seizures increase the risk of brain tumors, if seizures occur because of the tumor, or if anti-seizure medication increases the risk.
  • N-nitroso compounds. Some studies of diet and vitamin supplementation seem to indicate that dietary N-nitroso compounds may raise the risk of both childhood and adult brain tumors. Dietary N-nitroso compounds are formed in the body from nitrites or nitrates found in some cured meats, cigarette smoke, and cosmetics. However, additional research is necessary before a definitive link can be established.

The next section in this guide is Symptoms and Signs. It explains what body changes or medical problems a brain tumor can cause. Use the menu to choose a different section to read in this guide.


Risk Factors for Brain and Spinal Cord Tumors

Brain Tumors and the Risk of Stroke

A risk factor is anything that affects your chance of getting a disease such as a brain or spinal cord tumor. Different types of cancer have different risk factors. Some risk factors, smoking, you can change. Others, your age or family history, can’t be changed.

But having a risk factor, or even several, does not always mean that a person will get the disease, and many people get tumors without having any known risk factors.

Most brain tumors are not linked with any known risk factors and have no obvious cause. But there are a few factors that can raise the risk of brain tumors.

Family history

Most people with brain tumors do not have a family history of the disease, but in rare cases brain and spinal cord cancers run in families. In general, patients with familial cancer syndromes tend to have many tumors that first occur when they are young. Some of these families have well-defined disorders, such as:

Neurofibromatosis type 1 (NF1)

This genetic disorder, also known as von Recklinghausen disease, is the most common syndrome linked to brain or spinal cord tumors.

People with this condition have higher risks of schwannomas, meningiomas, and certain types of gliomas, as well as neurofibromas (benign tumors of peripheral nerves). Changes in the NF1 gene cause this disorder.

These changes are inherited from a parent in about half of all cases. In the other half, the NF1 gene changes occur before birth in people whose parents did not have this condition.

Neurofibromatosis type 2 (NF2)

This condition, which is much less common than NF1, is associated with vestibular schwannomas (acoustic neuromas), which almost always occur on both sides of the head.

It is also linked with an increased risk of meningiomas or spinal cord ependymomas. Changes in the NF2 gene are usually responsible for neurofibromatosis type 2. NF1, the gene changes are inherited in about half of cases.

In the other half, they occur before birth in children without a family history.

Having a weakened immune system

People with weakened immune systems have an increased risk of developing lymphomas of the brain or spinal cord (known as primary CNS lymphomas). Lymphomas are cancers of lymphocytes, a type of white blood cell that fights disease. Primary CNS lymphoma is less common than lymphoma that develops outside the brain.

A weakened immune system can be congenital (present at birth), or it can be caused by treatments for other cancers, treatment to prevent rejection of transplanted organs, or diseases such as acquired immunodeficiency syndrome (AIDS).

If a Brain Tumor is Not Cancerous, Why Do Anything About It?

Brain Tumors and the Risk of Stroke

Malignant and benign (non-cancerous) brain tumors have similar symptoms. They can cause seizures or cause neurologic problems, such as paralysis and speech difficulties. The difference between the two is that malignant tumors are cancerous and can spread rapidly into other parts of the brain, sending cancerous cells into surrounding tissue. Benign tumors can grow but do not spread.

There is no way to tell from symptoms alone if a tumor is benign or malignant. Often an MRI scan can reveal the tumor type, but in many cases, a biopsy is required.

If you are diagnosed with a benign brain tumor, you’re not alone. About 700,000 Americans are living with a brain tumor, and 80% of primary brain tumors — tumors that began in the brain and did not spread from somewhere else in the body — are benign. But if a tumor is not cancerous, do you have to do anything about it?

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“Even a benign tumor that’s growing inside the head is potentially dangerous,” says Robert Fenstermaker, MD, Chair of Neurosurgery at Roswell Park Comprehensive Cancer Center.

“There’s only so much room inside the skull, and the brain occupies most of it.

Even if a brain tumor is benign and growing slowly, eventually the brain won’t be able to tolerate that, and symptoms will develop, which can be life-threatening.”

Most benign tumors are treated with surgery, focused radiation or a combination of the two. “Increasingly, we’re finding that a combination is better than either one by itself. If a tumor is large, it’s hard to treat it with just radiation therapy. Surgery will help reduce the tumor's size,” says Dr. Fenstermaker.

“At the same time, it may not be safe to remove the entire tumor.

It could be touching or encasing blood vessels or other critical structures, such as nerves, and trying to remove the entire tumor could damage those structures.

What we’re doing is reducing the size of those tumors with surgery and then treating them with focused radiation, such as Gamma Knife radiotherapy, to control what’s left.”

What to Expect with Gamma Knife Radiosurgery

Gamma Knife patient, Keith Cordaro shares his experience receiving radiosurgery treatment at Roswell Park.

Read Keith's Story

In some cases, treatment may not even be necessary. Every patient is different. Each case depends on the size of the tumor and the age of the patient and whether symptoms have appeared.

“If a patient is older and the tumor is small, we may simply monitor the patient with MRIs on a yearly basis to confirm that the tumor is not growing.

So you may not need to treat them, as long as long as you follow them carefully,” Dr. Fenstermaker explains.

He stresses that if treatment is needed, it's still important that patients seek treatment at a National Cancer Institute-designated comprehensive cancer center Roswell Park, even for benign tumors.

“We treat brain cancer, but we also treat benign brain tumors. The same skill set is involved in each treatment. The question to ask your neurosurgeon is not necessarily, 'How many of this particular type of tumor have you removed?' but 'How many tumors have you removed or treated?'

“Also, as a patient, it’s important that you have exposure to a range of treatment options. These include surgery, radiation therapy and, in some cases, chemotherapy — all things that are offered at a comprehensive cancer center Roswell Park.”

There's always the risk of complications during surgery, and patients may be at risk of stroke during the removal of a brain tumor. In addition, temporary swelling of the brain may occur following surgery or focused radiation therapy.

Most patients see an improvement in their symptoms shortly after treatment of their benign tumors.

“The vast majority of people who have their brain tumors removed function better after treatment than before,” says Dr. Fenstermaker.

“There are risks to vital neurologic functions that can’t be reduced to zero, but the modern treatment of brain tumors is a great advance, and it greatly benefits most patients.”