Cancer Trends 28 - Primary brain cancer

The latest trends report (number 28) from the Registry on primary brain cancer has been published. Data shows that on average, 289 malignant primary tumours of the brain are diagnosed in Ireland every year, representing just under 2% of all invasive cancers. They are more commonly diagnosed in men than in women (by approximately 40%) and the median age at diagnosis is 60.

Astrocytic tumours, notably high grade glioblastomas make up the majority of all malignant brain cancers but almost 20% are not classified to subtype, largely a result of some patients, particularly the elderly, not undergoing biopsy or surgery and diagnosed through imaging or clinical assessment only. However there has been an increase in the proportion of patients pathologically diagnosed over time.

Incidence rates for primary brain cancers overall have remained more or less unchanged over the twenty year period 1994-2013 but a significant increase in the incidence of oligodendroglioma in particular has been observed. This was accompanied by a decline in the proportion of unspecified tumours over time.

Radiotherapy and surgery, either alone or in combination represents the main treatment for primary brain cancer. The use of chemotherapy to treat primary brain cancer has increased over time and Temozolomide currently represents the most common chemotherapy drug administered to patients.

Survival rates remain poor and for all primary brain tumours 5 year net survival remains unchanged at 19%, similar to figures in the UK. Glioblastoma and other high grade astrocytic tumours have the poorest survival with just 4% of glioblastoma patients surviving 5 years post diagnosis. The best survival was found for patients with ependymoma and embryonal tumours.

Incidence and mortality rates in Ireland are similar to those reported for the European Union overall.