Causes of Brain Cancer
It is not known what causes brain cancer and it appears to occur randomly. For the vast majority of people with a brain tumour, no outside cause can be clearly identified.
What Causes Brain Cancer?
A brain tumour is any abnormal mass of cells in the brain, which can be either benign (non-cancerous) or malignant (cancerous). Brain cancer specifically refers only to malignant tumours, fast-growing cells that invade surrounding tissue. Despite decades of research, the exact cause of brain cancers mostly remains unknown. While certain risk factors may increase the likelihood of developing a tumour, in most cases, no clear cause is identified.
What We Know — and Don’t Know
While researchers have identified a few factors that may influence brain tumour development, no single cause explains all cases. Genetics, previous exposure to ionising radiation, and rare hereditary conditions are among the few known contributors. Many suspected environmental or lifestyle causes, such as diet, stress, or mobile phone use, have not been proven to increase brain tumour risk.
Known Risk Factors for Brain Tumours
Some types of brain tumours are more common at certain ages. Most brain tumours arise from genetic changes that occur over time in a single cell, rather than inherited mutations, although rare inherited syndromes can increase risk. Mutations in certain genes that control how cells grow and divide can increase the risk of developing brain cancer. In healthy cells, these genes act like safety switches, telling cells when to stop growing. If this control system is disrupted, cells may continue to divide when they should not.
Problems in genes responsible for repairing DNA can also raise cancer risk. When DNA damage is not properly repaired, errors can accumulate over time, increasing the chance that cells will grow abnormally. A single change is usually not enough on its own, and tumours typically develop after multiple genetic changes build up over time.
In adults, the chance of acquiring genetic changes tends to increase with age, partly because cells have had more time to accumulate DNA damage. Additionally, cells experience more DNA damage from normal processes inside the body and from environmental exposures. Importantly, having these genetic changes does not mean a person will develop brain cancer, but it may increase susceptibility in some individuals.
Exposure of parents to certain substances known to damage DNA has been studied as a possible risk factor for some childhood cancers, including brain tumours. These exposures may affect sperm or eggs and, in rare cases, could contribute to genetic changes, which, in rare cases can be passed on to children and may increase susceptibility to cancer later in life.
It is important to note that these exposures do not mean a child will develop cancer. Childhood brain tumours remain rare, and in most cases no single cause can be identified.
Exposure to high doses of radiation, particularly during childhood, has been linked to a higher chance of developing brain tumours later in life. Ordinary medical imaging such as X-rays or CT scans carries minimal risk.
Syndromes like neurofibromatosis type 1, Li-Fraumeni or Turcot syndrome are extremely rare but can increase the likelihood of developing brain tumours. Seizures are a common symptom of brain tumours, and some patients may experience seizures or epilepsy months or years before a brain tumour is formally diagnosed.
As people age, natural immune surveillance can become less efficient, which may contribute to cancer risk later in life. Some tumours can also affect immune function by releasing substances that dampen the body’s immune response, making it harder for the immune system to recognise and control abnormal cells. In certain settings, such as severe immunosuppression, this can increase vulnerability to specific brain tumours, although for most brain tumours the role of immune status remains unclear.
What Does Not Cause Brain Cancer (Common Myths)
Many myths about brain cancer persist. Extensive research has not found evidence that mobile phones, Wi-Fi, stress, or sugar cause brain tumours. These factors have been studied, but no consistent link to brain cancer risk has been shown. Understanding what does not cause brain cancer is important to focus on evidence-based risk factors that are supported by scientific evidence.
Can Brain Cancer Be Prevented?
Currently, there is no proven way to prevent brain cancer. Maintaining general health and following medical advice may help your overall well-being, but it does not prevent the formation of most brain cancers.
When to See a Doctor
If you notice persistent headaches, nausea with vomiting, vision changes, seizures, or other unusual neurological symptoms, seek medical advice promptly. Early diagnosis and treatment can improve outcomes, even though the cause of the tumour may remain unknown.
Find out more about common signs and symptoms of brain cancer.
Frequently Asked Questions About Brain Cancer Causes
Does stress cause brain cancer?
Current research shows no direct link between stress and brain tumour development. While stress affects overall health, it is not considered a cause of brain cancer.
Can mobile phones or Wi-Fi cause brain cancer?
Scientific studies have found no evidence that mobile phones, Wi-Fi, or similar devices increase the risk of brain cancer.
Is brain cancer hereditary?
Most brain cancers are not inherited. A small proportion of tumours occur in people with rare genetic syndromes or family histories, but heredity accounts for very few cases. However, some people may inherit changes in genes that normally help control how cells grow and divide. When these genes do not work as effectively as they should, it can increase the risk of developing a brain tumour.
Can brain cancer be prevented?
There is currently no proven way to prevent brain cancer. Maintaining general health is important, but it does not eliminate risk.
What are the main risk factors for brain cancer?
Known risk factors include age, exposure to high-dose ionising radiation, and rare inherited genetic syndromes. A family history of certain brain tumours or cancer syndromes may increase risk in a small number of cases. For most people, no clear risk factor is identified.
Does diet or sugar cause brain cancer?
Current research has explored associations between diet and brain tumour risk, but findings are inconsistent and do not establish that specific foods or dietary patterns directly cause or prevent brain tumours.
References
Baldwin, R.T. and Preston-Martin, S. (2004) ‘Epidemiology of brain tumors in childhood – a review’, Toxicology and Applied Pharmacology, 199(2), pp. 118–131.
Bunin, G. (2000). What Causes Childhood Brain Tumors? Limited Knowledge, Many Clues. Pediatric Neurosurgery, 32(6), 321-326. https://doi.org/10.1159/000028961
Feychting M, Schüz J, Toledano MB, Vermeulen R, Auvinen A, Harbo Poulsen A, Deltour I, Smith RB, Heller J, Kromhout H, Huss A, Johansen C, Tettamanti G, Elliott P. Mobile phone use and brain tumour risk – COSMOS, a prospective cohort study. Environ Int. 2024 Mar;185:108552. doi: 10.1016/j.envint.2024.108552. Epub 2024 Mar 2. PMID: 38458118.
Ostrom, Q.T., Bauchet, L., Davis, F.G., et al. (2014) ‘The epidemiology of glioma in adults: a “state of the science” review’, Neuro-Oncology, 16(7), pp. 896–913.
Shu L, Yu D, Jin F. Healthy dietary patterns, foods, and risk of glioma: A systematic review and meta-analysis of observational studies. Front Nutr. 2023 Jan 4;9:1077452. doi: 10.3389/fnut.2022.1077452. PMID: 36687697; PMCID: PMC9845718.
Wiemels, J., Wrensch, M. and Claus, E.B. (2010) ‘Epidemiology and etiology of glioma’, Journal of Neuro-Oncology, 96(1), pp. 1–14.
Wrensch, M., Minn, Y., Chew, T., Bondy, M., & Berger, M. S. (2002). Epidemiology of primary brain tumors: Current concepts and review of the literature. Neuro-Oncology, 4(4), 278-299. https://doi.org/10.1093/neuonc/4.4.278