A study led by researchers in Madrid was conducted on 45 rats to prove that the active ingredient in cannabis, THC, had destroyed incurable brain tumors in rats. They found that out of the 15 cancerous rats they injected THC, only 3 of them showed ineffective results, while 9 surpassed the time of death of untreated rats and 3 showed complete eradicated tumors. The researchers boast that the United States had previously done a study in 1974 proving the beneficial effects on THC on cancerous tumors, yet research had been immediately shut down shortly after.
For further reading on this study please visit:
http://www.alternet.org/story/9257/