[Editor's note: This post is excerpted from this week's forthcoming NORML weekly media advisory. To have NORML's media advisories delivered straight to your in-box, sign up for NORML's free e-zine here.]

The administration of THC reduces the tumor growth of metastatic breast cancer and “might constitute a new therapeutic tool for the treatment” of cancerous tumors, according to preclinical data published online in the journal Molecular Cancer.

Investigators from Complutense University in Madrid assessed the anti-tumor potential of THC and JWH-133, a non-psychotropic CB2 receptor-selective agonist, in the treatment of ErbB2-positive breast tumors – a highly aggressive form of breast cancer that is typically unresponsive to standard therapies.

Researchers reported, “[B]oth Delta-9-tetrahydrocannabinol … and JWH-133 …reduce tumor growth [and] tumor number [in mice]. … [T]hese results provide a strong preclinical evidence for the use of cannabinoid-based therapies for the management of ErbB2-positive breast cancer.”

In 2007, investigators at the California Pacific Medical Center Research Institute reported that the administration of the nonpsychoactive cannabinoid CBD limited breast cancer metastasis in a manner that was superior to comparable synthesized agents.

Previous preclinical studies assessing the anticancer properties of cannabinoids have shown that they inhibit the proliferation of a wide range of cancers, including brain cancer, prostate cancer, oral cancers, lung cancer, skin cancer, pancreatic cancer, biliary tract cancers, and lymphoma.

Full text of the study, “Cannabinoids reduce ErbB2-driven breast cancer progression through Akt inhibition,” is available online here.