Delta9-Tetrahydrocannabinol and Cannabidiol as Potential Curative Agents for Cancer: A Critical Examination of the Preclinical Literature

An Internet search with search words cannabis cures cancer produce a wealth of sites claiming that cannabis has this effect. These sites are freely accessible to the general public and thus contribute to public opinion. But do delta(9)-tetrahydrocannabinol (Delta(9)-THC) and cannabidiol (CBD) cure cancer? In the absence of clinical data other than a safety study and case reports, preclinical data should be evaluated in terms of its predictive value. Using a strict approach where only concentrations and/or models relevant to the clinical situation are considered, the current preclinical data do not yet provide robust evidence that systemically administered Delta(9)-THC will be useful for the curative treatment of cancer. There is more support for an intratumoral route of administration of higher doses of Delta(9)-THC. CBD produces effects in relevant concentrations and models, although more data are needed concerning its use in conjunction with other treatment strategies.