Cancer and cannabis

A large body of preclinical research suggests that specific cannabinoids, such as CBD, can have anti-cancer and anti-tumor properties.

But how does this research in vitro is it reflected in the human body, an infinitely more complex and dynamic environment?

A study from October 2020 by a team of Bulgarian researchers summarized the anti-cancer effects of CBD and presented a tentative map of how CBD could enhance or support conventional cancer treatments.

Their study looks at the effects of cannabidiol on different cancer cells and explains how, when combined with conventional anti-cancer drugs, CBD can promote a special kind of synergy that improves cancer treatment outcomes.

How does CBD target cancer?

Both endocannabinoids, or cannabinoids produced by the body, and cannabinoids from the cannabis plant play a role in regulating pathways that affect cancer, including the growth, migration and spread of cancer cells.

The clinical use of THC is often controversial due to its intoxicating psychoactive effects. CBD, on the other hand, is not intoxicating, is well tolerated and has a good safety profile. It has been demonstrated that CBD reduces tumor growth and progression in cancers as diverse as breast, lung and colon.

Researchers have now begun to investigate how CBD might work synergistically with current chemotherapy treatments, and how this powerful cannabinoid can be transferred out of the laboratory and into the treatment room.

The effects of CBD on different types of cancer

In the 2020 Bulgarian study mentioned above, the research team explored the evidence supporting the use of CBD in the treatment of various types of cancer. Here are their findings on the three most common forms of the disease.

Breast cancer

CBD has an inhibitory effect on breast tumor cells, particularly the MCF-7 cell line, which is frequently used in cancer treatment drug research. The researchers discovered that CBD exerts a more powerful action in stopping the spread of breast cancer cells than other cannabinoids.

Lung cancer

Research conducted in 2012 revealed that CBD exerts a mechanism that prevents the spread of lung cancer tumors. The same research team also reported that CBD promotes cancer cell death in primary lung tumor cells.

Prostate cancer

Test-tube experiments on various prostate cell lines have shown that the shown that CBD decreases the expression of androgen receptors, which strongly influence the development and progression of prostate cancer. Inhibiting the activity of these receptors can delay the progression of prostate cancer.

CBD inhibits the growth and spread of tumors

One of the most problematic features of cancer is the spread of cancerous tumors throughout the body. Unlike ordinary healthy cells, cancer cells express a number of mutations that prevent cell death. These mutated cells can then spread and colonize other parts of the body.

Cancer research often focuses on where cancer originates, not on the secondary sites where it has spread. Fascinatingly, investigations into cannabinoids like CBD often focus on its ability to inhibit the progression of cancer cells that have already migrated and begun to form new tumors.

According to the Bulgarian study, CBD acts on a number of pathways in the body to encourage tumor suppression. One of the most important ways CBD slows tumor progression is through its modulation of the PI3K pathway, a major pathway that modulates cell growth, metabolism, survival and spread, and thus represents a target for cancer treatment.

How CBD can be combined with cancer therapies

According to the Bulgarian study, a number of reports advocate combination therapy approaches. Combining CBD with specific anti-cancer drugs has already been shown to make certain cancer cells more vulnerable to the effects of anti-cancer drugs.

In patients with pancreatic cancer, other landmark research has shown that CBD combined with chemotherapy can yield promising results, a type of cancer notorious for its resistance to treatment. Mice with pancreatic cancer lived almost three times longer when a conventional anti-cancer treatment, gemcitabine, was combined with CBD. In addition to prolonging life, CBD could also improve quality of life.

Another study has shown that CBD and conventional temozolomide treatment can be combined to more effectively treat gliomas - tumors of the brain and spinal cord.

CBD for the side effects of cancer therapy

Much research also supports CBD as an adjunct medication that prevents and reduces the side effects of cancer therapies. One of the most unpleasant effects of powerful anti-cancer drugs is peripheral neuropathy, which causes weakness, numbness and pain in the hands and feet. Up to 75% of patients may experience this following certain chemotherapy regimens.

CBD may help prevent the development of this sensitivity. According to a study 2014 in mice, doses of CBD administered prior to paclitaxel, a form of chemotherapy, prevented the development of nerve sensitivity in mice. Most importantly, the mice's nervous systems were not damaged, and the efficacy of the chemotherapy was not compromised by the treatment.

Another survey has shown that CBD can support the kidneys and reduce renal toxicity induced by cisplatin, a chemotherapy agent linked to kidney damage.

Does the future of cancer treatment include CBD?

Like many nascent areas of Cannabis science, data exploring CBD and cancer treatments is currently limited. What the Bulgarian journal 2020 exposes, however, is a body of evidence indicating the various ways in which CBD can support cancer treatments, and the need for more comprehensive clinical investigations to test its efficacy.