What causes a brain tumour?
No single, definitive cause has yet been identified for primary brain tumours, meaning those that originate in the brain rather than metastasising from another form of cancer such as breast, lung or melanoma.
Some risk factors have been identified, but due to the complex and unique health history for each patient, scientists are still unable to answer this fundamental question of why a brain tumour has appeared. Like all tumours and cancers, mutations in the DNA of a cell leads to abnormal growth (uncontrolled division), and as further mutations accumulate so the tumour can invade surrounding brain, but what causes these mutations is likely to vary between individuals.
What are the risk factors that might lead to a brain tumour?
We’ve collated extensive information in order to bring you the latest thinking on what environmental and lifestyle risks might be increasing the risk of being diagnosed with a brain tumour. We will be updating this page regularly so please do keep coming back for the latest information
Can radiation cause a brain tumour?
The most well known environmental risk factor for the development of brain tumours is exposure to radiation, especially where this has been used for previous cancer treatment in the same site.
Do mobile phones cause brain tumours?
Some scientists still strongly contest this and some studies suggest there is a connection between mobile phone use, glioma and acoustic neuroma (a form of schwannoma brain tumour).
We would recommend everyone follow the guidelines promoted by the The World Health Organization (WHO) – limiting mobile phone usage and using hands-free kits or the phone’s speakers. People should also be wary of keeping their mobile phones in their pockets close to their bodies for long periods of time, even if not in use.
Does the risk of getting a brain tumour increase with age?
As humans age, the higher the risk of developing a wide range of health conditions. For example, glioblastoma multiforme (GBM) brain tumour is most common amongst 75 to 84-year-olds
Can the risk of a brain tumour be inherited?
There is evidence that, in a very small number of cases, inherited genetic factors or conditions have contributed to the development of a brain tumour. These conditions include 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 tumours within some families without a link to these known hereditary conditions. Studies are underway to try to understand more.
Can pesticides and farming cause brain tumours?
There is some evidence of a connection between pesticide exposure (including some pesticides approved for domestic/home use), farming and an increased risk of developing a brain tumour.
This applies both to the development of brain tumours in adults (due to personal exposure to toxins) and to the development of paediatric brain tumours (due to personal childhood or parental occupational exposure to toxins, particularly for mothers during pregnancy but also for fathers pre-conceptually).
Unfortunately, the type of pesticides and specific brain tumours related to their exposure were not recorded in most of the studies that formed the basis of these reviews.
Certain chemicals have been shown to cause brain tumours in animal studies, but these results cannot be extrapolated to prove such a direct effect in humans.
Can chemicals cause brain tumours?
There are studies that suggest a connection between being a painter, working in the printing industry, being a hairdresser, personal hair dye use and an increased risk of developing a brain tumour.
No specific products or chemicals have been identified as being a direct cause of brain tumours, and any connection is hard to clarify due to the complexity of the wide variety of chemicals used in these industries, the variation in dosage and exposure time of individual people, and the interplay between chemicals and individual genetics and metabolism.
Scientists have also reviewed the association between a range of solvents, occupational exposure and glioma risk, but the results were inconsistent and the conclusions were that no firm causal relationship could be established.
Can what we eat cause a brain tumour?
High levels of blood glucose (blood sugar) is related to poorer survival rates in glioblastoma (GBM) brain tumours, but has not been identified as a risk factor. Neither has obesity, diabetes mellitus type 2, nor high cholesterol.
There is some evidence however of a connection between the consumption of cured meats containing nitrates (used as a food preservative) during pregnancy and an increased risk of the development of a glioma brain tumour in the child. However this is specific only to those who have a genetic predisposition related to nitrates and the potentially carcinogenic compounds formed from them during digestion. No risk for the occurrence of primary brain tumours in the general population has otherwise been established in relation to cured meats.
Can viruses cause a brain tumour?
The Epstein-Barr virus (EBV) has been indicated as a possible contributory factor to the development of gliomas, but it is not clear what role the virus may play, if any.
The Epstein-Barr virus is a member of the gamma herpes simplex family of DNA viruses and has been shown to cause infectious mononucleosis (glandular fever). It is strongly linked with the development of several cancers, including B-cell lymphomas, nasopharyngeal, and gastric carcinomas, which is why it has also been investigated in the context of brain tumours.
What drugs might cause a brain tumour?
A drug called Cyproterone Acetate or CPA acts on testosterone and is used in a number of medical conditions in low doses with no connection to the development of brain tumours. However when used in very high doses, for example to control aggressive sexual disorders or support transgender women, it has been shown to induce meningioma.
If the CPA is stopped, these meningioma tumours usually shrink and there is no need for any further treatment. It is therefore very important that you disclose to your medical team if you are taking CPA and have been diagnosed with a meningioma.
Would you like to participate in research that aims to discover more about risk factors for brain tumours?
There are websites where people can register their details so that researchers can get in touch if they begin a suitable study. Brain Tumour Research has a dedicated page with information about how to participate in research.
What causes a brain tumour?