http://www.telegraph.co.uk/science/science-news/8709920/Ecstasy-could-be-used-in-cancer-treatment.html
"Researchers from Birmingham University claimed the designer drug [Ecstasy], also known as MDMA, could be used to treat leukaemia, lymphoma and myeloma after making it 100 times more effective at suppressing growth. Ecstasy was already known to be effective against more than half of white blood cell cancers, but previously the large dose required to treat a tumour would also have killed the patient."
Here's a link to the abstract for the research article:
http://www.springerlink.com/content/384k8r14u2kvhv1h/
