====== High-grade glioma epidemiology ======

High-grade gliomas (HGGs) constitute the most common and aggressive [[primary brain tumor]]

High-grade gliomas are the most common primary [[malignant]] [[brain tumor]] in adults
((DeAngelis LM. Brain tumors. N Engl J Med. 2001;344(2):114–123.))
((Deorah S, Lynch CF, Sibenaller ZA, Ryken TC. Trends in brain cancer incidence and survival in the United States: Surveillance, Epidemiology, and End Results Program, 1973 to 2001. Neurosurg Focus. 2006;20(4):E1.))
((Surawicz TS, Davis F, Freels S, Laws ER Jr, Menck HR. Brain tumor survival: results from the National Cancer Data Base. J Neurooncol. 1998;40(2):151–160.)).

The top three most common sites for [[high-grade glioma]]s in the [[central nervous system]] involve the [[frontal lobe]] (25.9%), the [[temporal lobe]] (19.8%), and other brain areas (19.4%) 
((Louis DN, Ohgaki H, Wiestler OD, et al.: The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol. 2007, 114:97-109. 10.1007/s00401-007-0243-4)).

----
They represent a widely heterogeneous group of tumors, the most frequent of which is [[glioblastoma]]. 

see [[Glioblastoma epidemiology]].

Its annual incidence has risen over the last decades, particularly amongst elderly people.

Approximately 89,000 new [[primary brain tumor]]s are diagnosed in the [[United States]] each year, for which 27% are [[glioma]]s and 32.8% are [[malignant glioma]]s
((Ostrom QT, Gittleman H, Fulop J, Liu M, Blanda R, Kromer C, Wolinsky Y,
Kruchko C, Barnholtz-Sloan JS. CBTRUS Statistical Report: Primary Brain and
Central Nervous System Tumors Diagnosed in the United States in 2008-2012. Neuro 
Oncol. 2015 Oct;17 Suppl 4:iv1-iv62. doi: 10.1093/neuonc/nov189. Epub 2015 Oct
27. PubMed PMID: 26511214; PubMed Central PMCID: PMC4623240.
)).