Marijuana as treatment for prostate cancer

Here’s what doctors know

By Thomas Green, MD, 

Should anyone consider medical marijuana as a prevention or cure of prostate cancer at this time? PEDRO PARDO/AFP/Getty Images

Recently there has been an interest in prostate cancer and treatment with cannabis. I have treated men with prostate cancer for over 35 years. I have personally been treated for prostate cancer.

Therefore any article regarding this disease and any potential treatments are very interesting to me.

At this time we are able to treat local cancer of the prostate with an attempt to cure. Initially, we treat local cancer with radical surgery, external radiation therapy, radiation seeds, cryotherapy or laser therapy. Metastatic cancer cannot be cured, but usually can be controlled for years. This is usually initially treated with hormone deprivation therapy. When this is no longer effective and treatment is still indicated, we resort to chemotherapy.

Nonsurgical cancer therapy requires a treatment specific to the cancer cells, a good delivery system and targeting of the agent to the cancer cells to ensure adequate absorption, a high enough dosage to treat the cancer cells while limiting side effects. Basically, we need to create a smart bomb of a drug to focus on cancer cells without significant collateral damage.

Many medical marijuana authors quote two laboratory studies that showed either inhibition of growth or early programmed cell death of prostate cancer cells with cannabis.

One study used virally induced cells grown in the lab and the other used prostate cancer cells grafted to the skin of mice.

Putting these studies together we see that cannabis may have the ability to slow the growth of cancer or allow us to use less hormonal therapy to control the disease, but neither study shows the ability to prevent or cure prostate cancer.

While these studies show some promise for prostate cancer treatment with cannabis, more significant work is necessary to show adequate treatment levels of the drug in the living prostate gland and clear positive treatment criteria. In metastatic disease, we would have to show improvement in the tests that show metastatic disease in humans.

Should anyone consider medical marijuana as a prevention or cure of prostate cancer at this time?

We do not have sufficient data to support this idea. For me, it is too great a leap of faith from laboratory experiments to consider treating myself or others with medical cannabis for prostate cancer at this time.

In time with more experimental cannabis research, people are hopeful that medical marijuana will find it’s way into the treatment of prostate cancer.