There are some known risk factors that may predispose a person to an increased risk of developing a brain tumour. However, the contribution of these risk factors to the overall risk can be quite small. Risk factors are grouped into those that are modifiable and those that are not.
Non-modifiable factors
Age (note that the risk of all tumours increases with increasing age)
Family history
There are some known inherited genetic conditions which increase the risk (neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni, Turcot, Gorlin, Cowden)
Modifiable factors
Medical radiation
These may have been used during radiotherapy treatment
The risk from medical scans (eg. CT scans and x-rays) is considered to be very low
Weakened immune system
For example due to medications
Do keep in mind that having any of these risk factors does not actually mean that the person will get the disease. Often, I have found that there were no known prior risk factors in patients who turned out to have brain tumours.
