As you may have already surmised, after a series of diagnostic tests it was confirmed that I had stage IV prostate cancer, with bone metastases to my hips, spine, pelvis and more. Within an hour or so of being admitted into the hospital, these tests showed that my bones were riddled with tumors. My PSA levels, which are supposed to be at 5 or below, were at 5,900! I had never witnessed this elevated level in any patient in my forty three years practicing medicine. I was extremely anemic and required multiple units of blood. To say that I was very ill is an understatement.
Cannabis largely works on the cancer’s cannabinoid receptors. Tumors that have an abundance of receptors will be more likely to respond to cannabis. (Prostate cancers happen to have very densely populated cannabinoid receptors.) So, when cannabinoids activate the receptors on the tumor cells, a number of actions are triggered. These include:
Over the course of the last year, I had endured a lot of pain but I conveniently attributed it to arthritis and/or old back injuries. Then, last summer I began feeling fatigued, but who doesn’t from time to time? By November, I was so terribly weak that it was difficult to even get out of bed. I was short of breath and light-headed, and began having lower abdominal pain. I actually thought I was having an attack of diverticulitis. By the time I finally got to my GI doc and he saw how ill I was, he shipped me off to the emergency room. I was very concerned, to put it mildly.
Prostate cancer is the most common type of cancer in men. Statistics show that 11% of men will develop prostate cancer, and in African Americans the incidence is a bit higher. I was, and am, very lucky. I survived the immediate hospitalization and began treatment.
Being in agreement with recent federal bulletins stating that there is little need or benefit in annual PSA checks (a test for prostate cancer,) I had stopped checking my own PSA levels. In retrospect, I’m quite sure that a certain degree of fear played into the reason I ignored them. Not a wise decision.
– 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.
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.
– 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.
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.
– Pre-clinical studies (in vitro = cells in laboratory and in vivo = in mouse model) have shown the antiproliferative, anti-metastatic, anti-angiogenic and pro-apoptotic effects of cannabinoids in various malignancies (lung, glioma, thyroid, lymphoma, skin, pancreas, endometrium, breast and prostate). Even if an identified substance in vitro / in vivo appears to have a beneficial effect on a disease, it is important to realise that only one in 5,000-500,000 substances obtain a registration and becomes available to the patient (after 10-16 years of different study phases). Cannabis has never been clinically studied as a treatment for malignancy.
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.
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.
Many of you had questions and comments about the show. Here, one of our Specialist Nurses, Sophie, answers some commonly asked questions.
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
Q. Can cannabis help cure prostate cancer?
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.
It’s important to remember that it’s illegal to grow or sell cannabis in the UK. It’s also illegal to have any cannabis-based products, unless a doctor has prescribed them for medicinal use. CBD oil is legal, but only if it contains extremely low levels of THC (less than 0.2%). However, there’s little evidence to suggest CBD oil benefits cancer patients and there are still a lot of unanswered questions.
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.
But these studies have only looked at prostate cancer cells grown in laboratories or in mice. There’s a long way to go in understanding whether there might be similar effects in patients. Cells can behave very differently in humans, so we need clinical trials in humans to see if cannabinoids could be used to treat prostate cancer. We also don’t yet understand the mechanism by which the cannabinoids prevent prostate cancer cells from growing or dividing either.