Genetic Instability in Paediatric and Adult Brain Tumours

Abstract

1.1 Brain tumours in children and adults Primary Central Nervous System (CNS) tumours are considered to be those that originate in the CNS and usually remain there. Primary CNS tumours, despite not leading the cancer frequency rates, rank first among cancer types for the average years of life lost (Burnet et al., 2005). By contrast with other malignancies, where research has lead to the establishment of more successful treatment options, the diagnosis of a CNS tumour, particularly the more malignant histological types, still has devastating effects on the patients and their relatives, not only due to the dismal prognosis of these tumours with extremely high rates of mortality, but also to the great morbidity that actual treatment options cause (Laughton et al., 2008; Mulhern et al., 2004; Silber et al., 1992). The estimated annual worldwide age-standardized incidence of malignant primary CNS tumours is 3.5 per 100,000 people, which represents more than 200,000 cases. The rate is slightly higher in males (3.9 per 100,000 people per year) than in females (3.1 per 100,000 people per year) (Ferlay et al., 2008). The frequency of brain tumours is also higher in more developed countries (5.2 per 100,000 people per year) compared to less developed countries (3.0 per 100,000 people per year), probably due to diagnostic advances, as well as access to adequate health care in the developed regions (Ferlay et al., 2008; Wrensch et al., 2005). Similarly, estimated annual global age-standardized mortality of malignant primary CNS tumours is higher in males (3.0 per 100,000 people) than in females (2.2 per 100,000 people), with higher rates also in more developed countries (3.2 per 100,000 people) than in less developed regions (2.3 per 100,000 people) (Ferlay et al., 2008). The median age of diagnosis for all primary CNS tumours is 57 years, however the histology-specific median age ranges from 9 to 70 years ( Central Brain Tumor Registry of the United States [CBTRUS], 2010).