Cannabis as part of an integrative approach to treating cancer

 Dr. Joseph Cohen

(start with chapters 2 and 3 Integrative Oncology)

Functional Medicine and Cancer Prevention

Functional Medicine teaches us how to optimize health by finding, then eliminating, triggers of disease.  Pertaining to cancer, there are three levels of prevention- primary, secondary and tertiary.  The goal of primary prevention is to reduce the risk of developing cancer.  This involves food and lifestyle choices, including avoidance of carcinogens in our foods, air, water and chemicals to which we are exposed.  Secondary prevention involves screening and early detection in asymptomatic individuals. Examples of secondary prevention include Pap tests, colonoscopies, radiological procedures and lab tests. Tertiary prevention involves reducing the spread of existing cancers. Functional Medicine, therefore, focuses on reducing the individuals chance of developing cancer- primary prevention. In this chapter, I will discuss what I believe to be the role of cannabis in all three levels of prevention.  The American Institute of Cancer Research estimates that approximately 33% of cancers can be prevented simply by improving our diet, exercising and reducing exposure to toxins.  We should keep in mind that many chronic diseases have similar predisposing factors.  It is incumbent upon us, as practitioners, to educate and convince our patients that many cancers and other chronic diseases are preventable.

 We tend to give too much credence to our genes, therefore feeling as though we’re destined to develop certain types of cancers as well as other chronic disease such as type 2 diabetes, cardio-vascular disease, autoimmune disease and dementia.  Despite our genetic predisposition, most of these diseases are preventable and, as in the case both type 2 diabetes and autoimmune disease, is often reversible. With the advent of more sophisticated DNA testing we can screen patients to see if they have significant risk of certain types of cancer. 

 The American Cancer Society states that we can reduce cancer risk by maintaining a healthy body composition, exercising, eating a healthy diet and limiting alcohol consumption.  Our patients undergo a comprehensive test of their body composition and, when necessary, will have a consultation with our nutritionist and or personal trainer to reduce risk.  In addition to diet and exercise, we must modify our behavior and avoid tobacco, excessive sun exposure and misuse of exogenous hormones.

Consumption of foods high in antioxidants as well as nutritional supplements can reduce free radicals therefore reducing what is known as reactive oxidative stress (ROS).  This combined with chronic inflammation are two primary procarcinogens and are also known to contribute to other chronic conditions such as endothelial (blood vessel wall) dysfunction seen in cardio-vascular disease.  

Cannabis and Cancer: Treating Symptoms

Nausea and vomiting
We have known that cannabis can be effective in treating symptoms imposed by chemotherapy and radiation.  Dronabinol (Marinol) is a synthetic form of THC that has been prescribed since the 1980’s for the treatment of chemotherapy induced nausea and vomiting.  We know that whole plant cannabis is a much better solution.  The entourage- a combination of cannabinoids, terpenoids and flavonoids- provides us with a much greater anti-emetic effect with fewer side effects. 

Anyone who has used cannabis can tell you that it enhances appetite and accentuates the palate.  Anorexia, weight and muscle loss (sarcopenia) is a significant issue with patients with advanced cancer.  Through sophisticated body composition testing we can monitor whether our patients are gaining or losing muscle.  We know that muscle is a critical component to maintain health.  We see sarcopenia as a significant issue in our elderly population.  Those who can maintain muscle via resistance training tend to be healthier.  We know that our endocannabinoid, anandamide, when binding to our CB1 receptor in the hypothalamus may be involved with the reward aspects of eating.  Infants would not feed and thrive without the action of our endocannabinoids.

There a more CB1 receptors in our brain than all other neurotransmitter receptors combined. They are also found in the peripheral nervous system, whereas CB2 receptors are found in the periphery, but have low affinity in the brain.  Our endocannabinoids, anandamide and 2-AG, bind to these receptors. Anandamide has an affinity toward CB1 receptors while 2-AG binds to both CB1 and CB2 receptors.  Additionally, cannabinoids are potent anti-inflammatory agents.

Studies have shown that cannabis can significantly reduce cancer related pain, while concomitantly treating nausea, vomiting and anorexia.  I believe that a 1:1 CBD:THC ratio is most effective.  We have found that CBD has been beneficial in treating neuropathic pain especially with the addition of some THC.  Neuropathy is a common side effect of chemotherapy drugs.

Cannabis is an excellent treatment for insomnia, anxiety and depression- three issues that commonly effect cancer patients.  Indica dominant cultivars can be inhaled an hour before bed to allow the metabolites of THC to form so that one can fall asleep.  Indica edibles, taken before dozing off, will add about another 6 hours of sleep- fall asleep; stay asleep.  CBD is an excellent anti-anxiety medicine while THC and CBD can act as an anti-depressant.

Cannabis and Cancer: Anti-tumor Effects

There are three primary effects of cannabinoids

Apoptosis:  All of our cells have a programmed death known as apoptosis.  We want to enhance apoptosis in cancer cells while not having any negative impact on our normal, healthy cells.  Cannabinoids, particularly THC and CBD,  target apoptosis is cancer cells without effecting our good cells.

Angiogenesis:  Cancer cells grow at a much faster rate than our normal cells, therefore needing an increase in blood flow to feed those cells.  This process is  known as angiogenesis.  CBD and THC decrease angiogenesis in tumor cells, therefore starving them while having no negative impact on our normal cells.
Id-1 gene:  This is a gene that is found affecting a variety cancer types and can promote the spread of these cancers.  Cannabinoids can turn off this gene, therefore decreasing the spread of these tumors.

We always recommend the use of cannabis medicine in conjunction with recommendations by an oncologist, whether that be surgery, chemotherapy or radiation.  Since we do not adequate human trials or double-blind placebo controlled studies, we cannot make claims to our patients that cannabis will “cure” their cancer.