Abstract
The aim of this systematic review is to determine the effects of cannabidiol on breast
cancer cells in pre-clinical studies. A search was conducted in nine databases for preclinical
studies that have examined the effect of CBD on breast cancer. Thirteen studies
were found to have met the inclusion and exclusion criteria. The full texts were then read
and assessed using the inclusion and exclusion criteria. Six studies met the inclusion and
exclusion criteria – these included three in vitro studies and 3 mixed studies. The in vitro
components of the studies were assessed for quality via the modified CONSORT
checklist, and the in vivo (animal) component was assessed via the ARRIVE guidelines.
The majority of articles were poorly reported, specifically regarding the in vivo
components of the mixed studies. Higher quality studies are required with improved
reporting. Unfortunately there have currently been no clinical trials conducted on the
effects of CBD on breast cancer and the related literature is limited. CBD has been shown
to have anti-tumour effects on multiple breast cancer cell lines in in vitro and mixed
studies. More research is needed in this field as CBD may prove to be an anti-cancer
therapy with a low side-effect profile.