The effects of oral THC administration has been studied in more than 35 clinical trials for the treatment of chemotherapy induced nausea and vomiting and more than 40 clinical studies have examined the effects of cannabinoids on appetite modulation. Some studies have shown evidence that the active compounds in cannabis may produce palliative effects in cancer patients by preventing nausea, vomiting, and pain while stimulating the appetite.
A recent double blind, randomized, placebo-controlled trial of 360 cancer patients in 14 countries found that pain scores improved significantly when patients consumed the whole cannabis plant extract. Researches reported that the combination of CBD and THC may be an efficacious adjunct treatment for cancer-related pain for patients who do not get adequate relief from other pain-relief methods.
(Source: GW Pharmaceutical. 2009 Phase llb Cancer Pain Trial Data June 22, 2012)