Breast cancer is one of the most common cancers, affecting approximately 1 in 10 women at some points in their lives. Although the rates of mortality have declined since the late 1990s, certain breast tumors remain resistant to these conventional therapies like chemotherapy and surgery. In addition, many of these treatments have side effects that substantially impair patients’ quality of life. Therefore, new strategies with low adverse effects continue to be sought after.
Experimental evidence accumulated over the last decade supports that cannabinoids such as THC and CBD, the active components of cannabis and their derivatives, possess antitumor activity against a wide range of cancers. They exert such effects through binding to and activating cannabinoid receptors, CB1 and CB2, on the surface of cancerous cells. In the case of breast cancer, THC, CBD and their analogs have been found to inhibit proliferation, induce cell death and curb cell migration of different breast cancer cell lines in culture. More encouragingly, studies using mouse models of breast cancer have also proved cannabinoids to hamper tumor growth, angiogenesis (generation of blood vessels that nurture the tumor) and metastasis in animals. In addition, while potent against cancerous cells, cannabinoids are not toxic to non-tumorous cells. Last but not least, cannabinoid-based medicines have been proven very safe in thousands of patients enrolled in multiple clinical trials. For all of these reasons, many scientists are optimistic that medicinal cannabinoids can be incorporated into current standard treatment regimens for breast cancer to improve patients outcomes.