This is a topic people often call us about. Eating healthily, being physically active and staying a healthy weight is important for general health, but can be especially important for men with prostate cancer.
Staying a healthy weight may also mean your prostate cancer is less likely to spread after surgery or radiotherapy. And if you’re having hormone therapy to treat your prostate cancer, your treatment may be less effective if you’re very overweight.
At the moment, we don’t know if cannabis can help treat prostate cancer. Some studies have looked at the effect of chemicals in cannabis, called cannabinoids, on prostate cancer cells. There are two main cannabinoids that have been investigated – THC (tetrahydrocannabinol) and CBD (cannabidiol). The studies found that cannabinoids may stop prostate cancer cells from growing and dividing, cause prostate cancer cells to die, and stop prostate cancer cells from invading other tissues and spreading.
Q. Can cannabis help cure prostate cancer?
Did you see Bill Turnbull: Staying Alive on Channel 4? It’s a powerful documentary that follows the TV presenter and journalist currently living with advanced prostate cancer as he goes through chemotherapy, tries diets and complementary therapies, and speaks to others with the disease, including Stephen Fry.
Bill Turnbull’s powerful documentary got plenty of people talking about the various treatment options he tried. One of our expert Clinical Nurse Specialists answers some commonly asked questions.
Many of you had questions and comments about the show. Here, one of our Specialist Nurses, Sophie, answers some commonly asked questions.
Why? Well, firstly because there’s strong evidence that being overweight increases the risk of aggressive or advanced prostate cancer.
On the Internet, patients can get a lot of information about the curative effect of cannabis oil on prostate cancer but this information extrapolate the results of pre-clinical work to possible effects in people without any factual evidence. I often see patients in the doctor’s office showing me a website where it has been proven that cannabis oil can cure prostate cancer, which is obviously their own interpretation. In my view this can be a misleading message even though the website does not explicitly provide false information. The website [See figure below] shows information which is based on a study published in the British Journal of Cancer. This is correct, but the website “neglects” to mention that this is a publication of an in vitro study. The patient might not even know what an in vitro study is and is not aware that there are no studies on humans yet to prove this.
Human beings produce their own cannabinoids (endocannabinoids) according to need and are not stored in the body. Like endorphins, the human body produces endocannabinoids in response to activities such as physical exercise (the high of runners might be due to endocannabinoids, not endorphins!).
Medicinal cannabis must be distinguished from recreational cannabis which is used to achieve a psychotomimetic state of ‘high’. Cannabis strains used for recreational purposes contain a higher THC and lower CBD ratio than cannabis for medicinal use. Usually two cannabis plants are used: cannabis sativa which has a higher THC concentration and cannabis indica which has a higher CBD concentrate. The flavonoids are known for their antioxidant and anti-inflammatory effects. The terpenoids are resins (oil) with a strong odour.
– Nausea and vomiting: An initial study in 1975 showed a beneficial effect of THC on nausea induced by chemotherapy. Subsequently, two systematic reviews showed benefits of cannabinoids in nausea and vomiting due to chemotherapy, but most studies were observational or uncontrolled.
Use of cannabis in cancer
In our hospital’s daily practice we notice the popular use of cannabis oil in prostate cancer (PCa) patients. As a nursing specialist for urology, I have even met patients who are so convinced of the curative benefits of cannabis oil in treating prostate cancer that they replace standard treatment with the use of cannabis oil.
– Pain: Cannabinoids have been used for centuries to lessen pain. Historical texts and old pharmacopoeia noted the use of cannabis for menstrual cramps, pain during childbirth, and headaches. Studies have shown that the cannabinoids have no effect on acute pain and post- operative pain. Two placebo-controlled studies with a cannabis extract showed modest benefits when using cannabinoids in addition to opioids and other adjuvant pain-killers in cancer patients with chronic pain. However, the effect of cannabinoids in chronic neuropathic pain was clearly demonstrated in 29 randomized studies.
Cannabinoids (CBD) have been widely used in medicines for centuries to control pain, nausea or vomiting, and to stimulate appetite, especially in cancer patients. Both cannabinoids receptor 1(CB1) and cannabinoids receptor 2 (CB2) were highly expressed in cultured prostate cancer cells compared to normal prostate cell lines. CBD inhibits tumor growth in xenograft model.
Clinicians have been challenged to improve the treatment of biochemically recurrent (BCR) prostate cancer in which prostatic specific antigen (PSA) rises without radiological or clinical progression years after localized treatment (radical prostatectomy or radiation therapy) with or without hormonal treatment. Approximately 50-90% of men with high-risk prostate cancer will experience a BCR. Based on the abovementioned preclinical observations of CBD’s effect on prostate cancer and its safety data in two non-cancer populations, a phase I study of CBD in men with biochemically recurrent prostate cancer will be conducted.