In order for prostate cancer to exist, it is necessary that the male sex hormone receptors are activated, at least in the beginning stages of the illness. Interfering with the activation of these receptors is one method which is utilized to control the malignancy.
This abstract from Endocrinology in 1980 shows that the researchers found that tetrahydrocannabinol (THC) and cannabinol (CBN) from cannabis (marijuana) inhibited binding of the male sex hormone (an androgen) to the receptor site, potentially interfering with such processes as those in prostate cancer.
Specifically, the findings showed that CBN, THC, and THC metabolites functioned as androgen antagonists, interfering with the androgen action at the receptor level. This is similar to the approach taken when synthetic chemicals are given in an attempt to disrupt the growth of prostate cancer today.
