This very well controlled study from 2010 explored the effect that certain cannabinoid extracts have on cancer-related pain. The specific aim of this study was to see how these extracts measured up against opioid painkillers, which often result in dependence. Researchers found that a THC:CBD extract was effective in relieving patient's cancer-related pain with only mild to moderate side effects, and suggested that it be given for cancer pain which strong opioids do not completely take away.
In my personal opinion, I'd love to see marijuana and marijuana extracts given as a primary pain reliever, and opioid drugs given only when such endocannabinoid system modulators aren't enough.
