Chaga - search for the word Brain in the site below - and it talks about chaga being good for brain cancer.
http://www.alohamedicinals.com/chaga-gold-inonotus-obliquus.htm#.U04bVK1dUic
Chaga has Betulinic acid - which is shown to help brain tumors
http://en.wikipedia.org/wiki/Betulinic_acid