A recent review of the available literature on cannabinoids and cancer in children published by a team of Israeli scientists in The Israel Medical Association Journal concluded cannabinoids like cannabidiol (CBD) are effective in treating cancer. The team of physicians looked at preclinical evidence of cannabinoids' anti-cancer efficacy, clinical evidence of cannabinoids' anti-cancer efficacy, and cannabinoids' efficacy on pediatric tumors. For preclinical trials, researchers highlighted a 1975 study that found cannabinoids reduced tumor growth in in vitro and in vivo experiences. Tetrahydrocannabinol (THC) was effective against lung cancer. More research from the 2000s found cannabinoids had anti-cancer effects on gliomas and various types of tumors, like prostate, breast, leukemia, lymphoma, pancreas, melanoma, thyroid, colorectal, and heptocellular carcinoma, in animal and cultural models. More research into the cannabinoids' therapeutic mechanisms is desired, but what is known is that they induce cell death, inhibit cell growth, and inhibit tumor angiogenesis invasion and metastasis.
There are fewer clinical trials, but researchers were able to identify a human trial involving nine patients that suggested THC treatments effectively decreased tumor growth and slowed tumor progression. There were no clinical trials involving the anti-cancer effects of cannabinoids on pediatric tumors, but in one preclinical trial, CBD effectively reduced the viability and invasiveness of the aggressive pediatric tumor, neuroblastoma. That same study found THC and CBD effectively treated xenograft tumors in mice, with CBD being the more effective of the two. The review urges for more clinical trials to investigate cannabis' anti-cancer effects.