Brain tumor

Incidence

Incidence

  • Brain tumors represent 85% to 90% of all primary tumors of the central nervous system.
  • The mortality rate is 4.22 deaths per 100,000 people a year.
  • Around 250,000 new cases are diagnosed per year worldwide.
  • There is a higher incidence among Caucasians.  The mortality rate is higher in men than in women.
  • Causes: 
    • Although the causes of these tumors are not known exactly, exposure to vinyl chloride seems to predispose to the development of gliomas. Gliomas (anaplastic astrocytoma and glioblastoma multiforme) represent 38% of primary brain tumors. Meningiomas and other tumors account for approximately 27% of primary brain tumors in adults. 
    • Primary lymphoma of the brain seems to be related to persons infected with the Epstein-Barr virus, having undergone a transplant or suffering from AIDS.  These persons could experience a higher incidence rate of primary lymphoma of the central nervous system. 
    • Tumors with a lower incidence rate are: oligodendrogliomas, astrocytomas, low-grade lymphomas, medulloblastomas, ependymomas, schwannomas or pituitary. 


The most common malignancy in the central nervous system is brain metastases.  It exceeds a ratio of 10/1 compared to primary tumors. Between 20% and 40% of malignant tumors produce brain metastases.  This figure may increase because patients are currently living longer as a result of the positive response to current cancer treatments. 

Some tumors more than others produce brain metastases during their evolution.  They include lung cancer include (50%), breast cancer (15-20%), cancer of unknown primary origin (10-15%), melanoma (10%) and colon cancer (5%).