Here ya go hun,
http://jpet.aspetjournals.org/content/308/3/838.abstract (look down and the side for more studies)
Guzmán M, Duarte MJ, Blázquez C, et al.: A pilot clinical study of Delta9-tetrahydrocannabinol in patients with recurrent glioblastoma multiforme. Br J Cancer 95 (2): 197-203, 2006.
[PUBMED Abstract]
Velasco G, Sánchez C, Guzmán M: Towards the use of cannabinoids as antitumour agents. Nat Rev Cancer 12 (6): 436-44, 2012.
[PUBMED Abstract]
http://www.gwpharm.com/oncology.aspx#glioma
We have Sativex trials in the US right now. Here's the info on it. They have already done other studies.
http://clinicaltrials.gov/show/NCT01812616
The problem for your Matt is the fact he doesn't have a pathology confirmation. It's also important to remember that Cannabis seems to work best with Glioblastoma Multiforme, not Astrocytoma or the others. Could they do a stereotactic biopsy? Even if they had to go in transphenoidally this could possibly help him gain access to the Sativex study.
Anyway I don't have enough specific information about him so I can't really give any type of opinion. Just suggest he discuss his options regarding this with his surgeon.
Good luck and bless you for backing your friend like this,
Annie