Prepared by staff in Prevention and Cancer Control. Citation: Cancer Care Ontario. Cancer Fact: Information on benign brain tumours being collected to better understand their impact. Oct. 2015. Available at http://www.cancercare.on.ca/ cancerfacts. Prepared by staff in Prevention and Cancer Control. Information on benign brain tumours being collected to better understand their impact (Oct. 2015) Registration of benign brain tumours in the Ontario Cancer Registry began in 2010 so that their impact could be better understood. Benign brain tumours are more common than malignant brain tumours and can be as life-threatening as malignant tumours. After several years of data collection, it will be possible to examine new trends, such as survival, in benign brain tumours. The Ontario Cancer Registry began tracking benign brain and central nervous system (CNS) tumours in 2010 to better capture their impact on the Ontario population and the healthcare system. Although benign (non-cancerous) brain tumours normally do not spread to surrounding tissue like malignant (cancerous) brain tumours, benign tumours can still be life-threatening because they compress and damage normal parts of the brain. Each year, more benign brain and CNS tumours are diagnosed than malignant tumours. In 2010–2012, an average of 1,766 benign brain tumours were diagnosed in Ontario annually, compared to 1,180 malignant tumours. Traditionally, cancer registries have only included information about malignant tumours, but because of the morbidity and mortality associated with benign brain tumours, information on all brain tumours is now being collected by provincial, territorial and state registries in North America. The new data gathered by these registries will allow researchers to study the entire spectrum of these diseases and better help people who suffer from them. In the future, when more years of incidence data become available, it will be possible to examine survival and time trends in benign brain and CNS tumours. Meningiomas are the most common type of benign brain tumour, accounting for 60 per cent of them. They develop from the meninges, which are the layers of tissue covering the brain and spinal cord. Although these tumours are twice as likely to occur in women as in men, all other benign brain and CNS tumours are found almost equally in men and women. Incidence of benign and malignant brain and CNS tumours increases with age. Malignant brain tumours are more common in childhood and benign tumours are more common at all other ages, with rates rising sharply after age 75. Starting at age 30, the number of new cases of benign brain and CNS tumours is higher in women than in men due to a higher incidence of meningiomas. There are a variety of known risk factors for brain tumours, benign or malignant, including radiation exposure, inherited conditions, family history, personal history of childhood cancer and a weakened immune system (see http://cancer.ca/en/cancer-information/cancer-type/brain-spinal/risks/?region=on). Although some studies have linked cellphone use with benign and malignant brain tumours, more research is needed to further investigate this association.