Published in the International Journal of Cancer Research and Treatment, a study on 119 cancer patients over a four-year period found that CBD may effectively treat several forms of cancer.
Treated with a pharmaceutical-grade synthetic form of cannabidiol, researchers found a clinical response in 92% of patients. Several forms of cancer were treated such as breast, brain, prostate, and colorectal cancers. CBD has been tested on cancer in previous studies, generally showing effectiveness in pain relief and the ability to kill cancer cells, especially in breast cancer and brain tumors.
UK Study Finds CBD May Help Treat Cancer
A recent study by researchers in the UK has found cannabidiol (CBD) may treat various cancers.
All of the 119 patients had advanced, metastatic cancer, and most of them had exhausted their other treatment options.
While most patients were not taking CBD as their only treatment (28 of the 119 were given CBD as their only treatment), the results showed 92% of patients achieved a clinical response with CBD.
Twelve patients were tumor free, 45 had stable disease (the tumor is neither growing nor shrinking, and it has not metastasized further), 43 extended the median survival, and eight saw their cancer progression slow.
Researchers gave patients an average dose of 10 mg of CBD twice a day, and patients took CBD on a three-days-on, three-days-off pattern. Some patients who were given CBD on a daily basis did not do as well as those on the on-off treatment.
Interestingly, there was a “complete absence of side effects” from using CBD.
The study also noted a couple of “impressive” cases that demonstrated CBD’s efficacy.
In one case, a young boy had anaplastic ependymoma, a rare, rapidly progressing tumor in the brain and spinal cord.
The boy had gone through several treatments including surgery, chemotherapy, and radiotherapy with no success.
When he had run out of options, he was given CBD in February 2016. By December 2016, the tumor had decreased by nearly 60% because of CBD.
Researchers concluded synthetic CBD was a candidate for treating breast cancer and glioma.
How CBD Treats Cancer
Cancer is a proliferation of damaged cells that infiltrate healthy tissue and spreads.
Effective anti-cancer agents must help control the proliferation of these cells and kill the existing cancer cells.
In a 2014 review of scientific literature by researchers at the Sanjay Gandhi Post Graduate Institute of Medical Sciences and The Ohio State University, evidence was found that CBD may have both antiproliferative and apoptotic (capable of inducing programmed cell death) abilities.
CBD’s Antiproliferative Effects
CBD interacts with a part of the body called the endocannabinoid system (ECS), which helps maintain balance in the body, or homeostasis.
The ECS is known to regulate several functions, including the life cycles of cells.
Thus, when cancer is present, the ECS is unable to function properly; fortunately, however, CBD can help restore the function of the ECS.
CBD is also able to prevent proliferation by interacting with several receptors and cell signaling pathways, which are locations on the membranes of cells that transfer messages from outside of the cell into the cell.
Inflammation also plays a role in the proliferation of cancer cells.
As the immune system attempts to destroy cancer cells, it initiates an inflammatory response that often does more damage than good by raising the risk of proliferation and metastasis.
CBD is a potent anti-inflammatory known for inhibiting the proliferation of cytokines (inflammatory proteins produced by the immune system) and preventing their production.
In turn, this helps prevent cancer cells from spreading.
CBD’s Apoptotic Effects
CBD can induce the deaths of cancer cells through a variety of mechanisms.
One such mechanism is through activation of special enzymes called caspases. These enzymes essentially tell a cell to start a process that causes the cell to die.
Another way CBD helps kill cancer cells is by inducing oxidative stress, which is interesting since CBD is also a powerful antioxidant.
Oxidative stress is caused by an imbalance of reactive oxygen species (ROS), also known as free radicals (unstable molecules with an unpaired electron), and antioxidants.
These free radicals can cause other cells to become unstable if not enough antioxidants are present, creating a chain reaction.
While oxidative stress can cause damage to healthy tissue, it can also be helpful in destabilizing cancer cells and causing their death.
Additionally, CBD can interact with some receptors to help induce apoptosis.
CBD’s Palliative Effects
CBD has other cancer benefits as well, including playing a role in pain relief.
CBD can help relieve inflammatory pain by inhibiting the inflammatory response of the immune system, which as mentioned, may also reduce the risk of metastasis and proliferation.
A study by UK researchers at the Severn Hospice also found that CBD helped provide pain relief in conjunction with tetrahydrocannabinol (THC), the psychoactive compound in marijuana.
The study tested Sativex, a cannabis medication with a 1:1 ratio of CBD to THC, on patients with advanced cancer pain who found no help with opioid pain relievers.
The researchers also gave other groups of patients a medication with only THC and a placebo.
The entire study population included 177 patients.
About 43% of patients taking Sativex saw a 30% or greater reduction in their pain scores, which was nearly double the number of patients who saw the same effect in both the THC-only and placebo groups.
Since the Sativex medication outperformed both the placebo and THC-only treatments, researchers believe that “CBD may enhance the analgesic potential of THC.”
Other Studies On CBD For Cancer
Several studies have been conducted on CBD for cancer, but most studies have focused on the cannabinoid’s effects on breast cancer and brain tumors.
CBD And Breast Cancer
In 2011, researchers from the Beth Israel Deaconess Medical Center in Boston discovered the effects of CBD on breast cancer cells.
In breast cancer, the disease increases the expression of fatty acid amide hydrolase (FAAH), an enzyme that breaks down an important endocannabinoid called anandamide.
Anandamide regulates cell proliferation and cell apoptosis; thus, with the increase of FAAH, anandamide is decreased in the body and cannot fight the cancerous cells.
CBD is known to inhibit the function of FAAH and therefore enhance anandamide levels in the body, allowing the endocannabinoid to help kill cancer cells and prevent their production.
Also, CBD inhibits the signaling of specific pathways (AKT and mTOR) in cells that decreases proliferation in breast cancer.
Finally, CBD killed cancerous cells by inducing two types of processes: apoptosis and autophagy, both of which are natural, programmed ways to cause the death of cells.
CBD And Brain Tumors
A study by researchers at the University of Camerino in Italy found different mechanisms by which CBD could fight brain tumors.
CBD induced the death of glioma cells by activating caspases (special enzymes designed to cause cell death) and reactive oxygen species (free radicals).
CBD also seemed to activate the TRPV2 ion channel that allows the cannabinoid to work with other anti-cancer agents in the body to cause further apoptosis of glioma cells.
These are likely the mechanisms CBD used to significantly reduce the size of the tumor in the case of the young boy with anaplastic ependymoma in the Dove Clinic study.
Is Treatment With CBD Alone Enough?
While existing research is encouraging, scientists do not recommend using CBD as the only treatment against cancer unless all other standard treatments have failed.
“We would not expect any significant anti-cancer activity using continuous CBD alone,” states researchers in the Dove Clinic study. “Cannabinoids have an accepted useful role in the management of cancer symptoms… but not as part of primary treatment.”
However, according to researchers, the improvement CBD demonstrated in the study’s patients warrants more attention.
“The fact that we have been able to document improvement in cancer in few [sic] patients strongly supports further studies of CBD-based products in cancer patients who have exhausted standard treatments,” concluded researchers.