Prostate cancer is a major cause of death among men worldwide. A large number of research studies have characterized cannabinoids as powerful regulators of cell growth and differentiation and therefore, as effective inhibitors of prostate cancer cells. However, in the clinic, cannabis and cannabinoids are only utilized as palliative treatment to relieve symptoms of cancer and side effects of chemotherapy. To evaluate this understudied potential of cannabis and cannabinoids as the main therapy for prostate cancer, a group of clinical researchers from Australia systematically reviewed and summarized all articles that reported their anti-tumor effects in mouse models of prostate cancer.
Although cannabinoids can be plant-derived (such as THC, CBD) or synthetic (i.e. synthesized in the lab), the majority of the studies reviewed employed synthetic cannabinoids, including WIN55,212-2 and PM49. Data from these studies indicated that WIN55,212-2 reduced cancer cell proliferation in several different strains of prostate cancer mice, with an effectiveness of up to 70% reduction. PM49 was also found to result in a significant inhibition of tumor growth, reducing tumor size by 40% to 90%. The potency of the substances varied across articles depending on the dose and length of treatment used. However, altogether, these studies corroborated one another and highlighted that cannabinoids can decrease the size of prostate cancer tumors in animal models.