It is also important that we inform the patient about the possible interactions of cannabis oil with certain regular medications such as Coumarin (this blood thinner interacts with cannabis oil, leading to an increase of the INR and a greater risk of bleeding!). There are different types of cannabis oil available, such as CBD and THC oils with different concentrations which makes it difficult for patients to make a choice.
Cannabis contains more than 400 chemical components 80 of which contain cannabinoid components and 200 non-cannabinoids components. For medical purposes, cannabinoid substances such as THC (Delta-9-tertrahydrocannabinol), CBD (cannabidiol) and non-cannabinoid substances such as terpenoids and flavonoids are relevant.
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.
In vitro studies with THC have shown that cannabinoids affect migration, angiogenesis and apoptosis (programmed cell death) of cancer cells, but each type of cancer appears to respond differently to the effect of exogenous cannabinoids. Many types of cancer cells have a higher concentration of CB1 and CB2 receptors.
In the 1990s, the endocannabinoid system (ESC) of the body was discovered by Raphael Mechoulam, an Israeli professor of medical chemistry. The endocannabinoid system, a central regulatory system, is the body’s largest receptor system and is important to maintain the homeostasis of the body.
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.
These patients include those who have localised prostate cancer where active surveillance is followed, those with biochemical recurrence after treatment, and patients with metastatic PCa. I have always wondered whether cannabis oil could indeed be a cure for prostate cancer. Unfortunately, I do not see in practice the desired beneficial effect and the PSA values continue to rise. To find some answers, I did a search in scientific literature.
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.
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.
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.
If you’re experiencing side effects from prostate cancer treatment, such as weight gain, bone thinning or hot flushes from hormone therapy, bowel problems or urinary problems, making changes to your lifestyle may also help you manage them.
There’s some evidence that cannabis-based medicines can help with long-term pain, including pain caused by cancer. Currently doctors in the UK can only prescribe cannabis-based medicines to treat nausea or vomiting caused by chemotherapy – when other medicines haven’t worked. Cannabis-based medicines aren’t available to treat cancer-related pain unless you’re taking part in a clinical trial. If you’re interested, your doctor should be able to tell you about any clinical trials that might be suitable. You can also search for clinical trials at www.bepartofresearch.nihr.ac.uk