Monthly Archives: September 2016

Green Science: The Role of Medical Marijuana in Cancer Therapy

martin-marijuana-blog-pictureCanada has announced that in 2017 it will make a monumental change to the drug policy relating to the use of marijuana.  The change to the drug policy will pursue the benefits of marijuana while emphasizing shared responsibility, compassion and human rights.  As these changes take place, it is our responsibility to examine the scientific data that support our decisions.  For many people, medical marijuana can help alleviate symptoms of pain, nausea, anxiety, and appetite loss.  Therefore, changes in legislation that ease restrictions will benefit many people living with chronic disorders.  Anecdotal and (some) scientific evidence already suggest there is much to be gained for medical conditions including epilepsy, cerebral palsy, and cancer.  In these cases, medical marijuana can be obtained in many forms including dried buds, oil extracts, and fresh leaves that can be eaten. It is important to remember that while marijuana will undoubtedly provide some benefit, smoking in any form is considered extremely carcinogenic.  That is, the tar and chemicals that our lungs are exposed to during smoking will cause cancer.  Therefore, it is critical to understand the chemicals in marijuana to control administration and eliminate the unwanted side effects of smoking or consuming raw extracts.

One such family of chemicals in marijuana is the cannabinoid family.   These chemicals act on the central nervous system by connecting to receptors found mainly on our neurons.  One cannabinoid, delta-9-tetrahydrocannabinol (THC), is the chemical that causes the major psychoactive effect, or ‘high’, associated with marijuana use.  Many studies show promising health benefits associated with purified THC.  However, while THC is arguably the most famous active chemical in marijuana, clinicians would ultimately prefer to yield a cannabinoid that does not alter a patient’s cognition.  The answer will likely be found in one of the approximate one hundred other cannabinoids that have yet to reveal how they affect the cells of our body.  One type of cannabinoid showing promising results are the cannabidiols (CBD). Because they connect to receptors that are slightly different than THC, CBDs do not elicit the psychoactive effects that are unwanted in everyday life.  Several studies have shown benefits to those living with epilepsy, cerebral palsy, and cancer.  If studies are able to prove the benefits of CBD, it will undoubtedly become a major treatment option for managing daily symptoms.

For cancer, the benefits of CBD may extend far beyond managing symptoms.  Large studies are currently being conducted that hope to harness direct anti-tumor properties.  Several pathways have already been identified that indicate CBD may inhibit the growth and spread of some cancers, including solid and blood-borne cancers.  One study seeks to combine CBD with traditional brain cancer treatments in the hopes of seeing benefits on killing cancer cells (Nabissi et al., Carcinogenesis (2013) 34(1), pp. 48-57).  Other studies are looking at close comparisons between anti-tumor effects on brain cells between THC and CBD in the test tube and mice (McAlister et al., Molecular Cancer Therapeutics (2007) 6(11), 2921-2927). As we uncover more about CBD it could provide the benefits of marijuana while eliminating the unwanted mind altering side effects and heavy stigma associated with smoking marijuana.

Throughout any discussion of the medical and scientific benefits, it is important to remember that marijuana use is currently illegal in Canada.  Anyone that needs marijuana for medical purposes must obtain a letter from their medical practitioner and purchase all products from licensed dispensaries.  On the other hand, our friends to the south, the United States of America, have already implemented some policy changes.  Marijuana has been legalized in several states providing both social and economic benefits.  Perhaps an even more powerful statement illustrating that the US government has recognized the potential of marijuana is the fact that CBD extracts from hemp are legal in all states. This makes it easier for  families pursuing this line of symptom management and provides scientists a far easier path to understanding how CBD works.  As Canada moves forward with marijuana legislation, we will certainly learn more about this provocative substance.

This article was written by Dr. Martin Smith. Dr. Smith completed his PhD at the University of Waterloo studying how proteins can cause cancer. He currently works for the Ontario Brain Institute where he studies brain disease. To learn more about Dr. Smith and his research check out our members page.

The Easiest Place to Hide is in Plain Sight

martin-melanoma-articleIn recent years one type of skin cancer has received particular attention due to one person in particular.  Jimmy Carter, the 39th President of the United States of America, brought melanoma into the public eye when he announced that doctors were treating him for several metastasized “spots on his brain”.  Thankfully, soon after treatment Mr. Carter announced to the world that his cancer was in remission.

What is melanoma? Melanoma is a skin cancer that affects the cells that produce color, also known as melanocytes.  Scientists are showing that overexposure to the sun causes changes in the DNA of melanocytes leading to tumors on the skin.  Some may think that because melanoma is on our skin it would be the easiest of cancers to spot.  However, a melanoma is often hidden amongst the healthy moles on our body,  allowing this menacing mole to go undiagnosed until it spreads to other parts of the body.  Once melanoma has metastasized, treatment options can become limited.

But, let’s return to the successful case of Jimmy Carter.  As described in the media, his treatment was a combination of the three pillars of cancer treatment: radiation, surgery and chemotherapy.  One part of the chemotherapy is the drug called Keytruda, also known as pembrolizumab.  The drug is an example of new immunotherapies, called antibodies, which recognize specific targets in your body.  When they find their target, they turn on immune cells to identify and destroy cancer cells.  It is one example of a growing number of treatments that are based on helping our immune systems recognize cancer.  As the number of antibody treatments increase, successful cases like this one are on the rise.   Mr. Carter’s personal triumph over cancer emphasizes the need for effective diagnosis and aggressive treatment.

In addition to diagnosis and treatment, there are several important things that we can do every day to help prevent melanoma.  We know that melanoma and other skin cancers are caused by exposure to the sun.  The Canadian Cancer Society has recently released guidelines for good sun practice.  In order they are: check UV (stay out of the sun between 11-3 when UV is 3 or higher), seek shade, cover up (clothes, hat, sunglasses), and wear sunscreen (broad spectrum, SPF of 30).  For more information check out this page from the Canadian Cancer Society.  In general, cancer prevention should also include quitting smoking, limiting alcohol intake, moderate exercise and a healthy diet.  Just remember: in the the hot days of summer when we play sports and picnic outdoors, it’s incredibly important to stay safe while enjoying the sun.

This article was written by Dr. Martin Smith. Dr. Smith completed his PhD at the University of Waterloo studying how proteins can cause cancer. He currently works for the Ontario Brain Institute where he studies brain disease. To learn more about Dr. Smith and his research check out our members page.