Cannabis and cancer treatment

Over the past few years scientists slowly turned their attention to the medical applications of cannabis. So far, a number of studies have shown beneficial effects of several cannabinoids on cancer and other medical conditions.

Cannabinoids make radiation more effective

Recently a new study was published in the journal 'Molecular Cancer Therapies'. Low doses of both THC (tetrahydrocannabinol) and CBD (cannabidiol ) were found to make brain cancer cells more receptive to radiation.

Mice were infected with glioma, a very aggressive form of brain cancer. Subsequently, different cures were tested. A treatment of cannabinoids without radiation barely had effect. Only in combination a dramatic reduction of tumours occurred: they shrunk to one-tenth the size of those in the control group. A high dose of either THC or CBD had similar effects as a low dose of the two cannabinoids combined.

According to Dr. Wai Liu, oncologist at St. George's University of London and one of the leading authors of the study, the cannabinoids have effect by modifying the faulty signaling pathways inside these cells.

Other medical applications

A year ago the same London based research group found that a combination of six purified cannabinoids (CBD, CBDA, CBG, CBGA, CBGV and CBGVA) kills tumour cells in leukemia, a different type of cancer.

Previous studies have already shown that THC reduces the size of certain cancerous tumours, for example in lung cancer, and stops these cancer cells from spreading. THC was also found to kill brain cancer cells and to stop the spread of HIV.

CBD appeared to have a profound effect on people suffering from seizure disorders and in itself could stop the metastasis in many forms of aggressive cancer.

In an observational study with people suffering from diabetes, recent cannabis use was linked to a better blood sugar control.

Cannabis-derived medicines

So far, a couple of products containing cannabinoids have been licensed for medical use. Sativex, for example, contains an equal mixture of THC and CBD and is commercially available as a mouth spray. It's been prescribed to treat spasticity caused by multiple sclerosis. Other cannabis-derived drugs Dronabinol and Nabilone are licensed for treating cancer-related side effects. Another range of cannabis-derived drugs is still under development.

Is smoking cannabis healthy?

Scientific results like these lead many to believe that smoking or vaporising cannabis is equally healthy. However, this not yet clear at all. When asked by the Huffington Post, oncologist Liu says he considers it unlikely: "Smoking cannabis introduces a number of potential problems. First, the complex makeup of cannabis that contains about 80 bioactive substances means that the desired anticancer effect may be lost because these compounds may interfere with each other.”

A second point he raises is the method of administration: “We see that delivering the drug either by injection or by a tablet would ensure the most effective doses are given. Smoking would be variable, and indeed the heat of the burning may actually destroy the useful nature of the compounds." Additionally, it’s clear that smoking any substance has many adverse effects on the lungs.

Other researchers have pointed out that dosage is critical to outcome in cancer treatment: a wrong dose can sometimes increase tumour growth.

Besides studies that point out the medical benefits of cannabis or cannabinoids, a number of studies has investigated its negative side. Cannabis is for example known to increase the heart rate and may cause birth defects when used during pregnancy. Again, smoking as method of consumption has a range of adverse effects on health.

Much research is still preliminary and (lack of) funding of these kind of studies has often been criticised. Observational studies are equally unclear as cannabis is regularly used in combination with alcohol, tobacco and other substances. Thus the exact health effects (both beneficial and harmful) of cannabis still remain unclear.

Sources:

-"Marijuana Drastically Shrinks Aggressive Form Of Brain Cancer, New Study Finds" Huffington Post

-"New Research Shows How Marijuana Compound Can Reduce Tumor Growth In Cancer Patients" Huffington Post

-"Marijuana Compounds Can Kill Some Cancer Cells: Study" Huffington Post

-"How cannabis was used to shrink one of the most aggressive brain cancers" The Conversation

-"Marijuana tied to better blood sugar control" Reuters

-"10 Pharmaceutical Drugs Based on Cannabis" Medical marijuana Procon

-"Adverse effects of cannabis" NCBI



Written by: Juniper