Medical cannabis and breast cancer – what does the evidence say?

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Increasing numbers of breast cancer patients are using medical cannabis to help manage their symptoms and side-effects of treatment, but is the evidence there to back it up?

According to the NHS, breast cancer is the most common form of cancer in the UK, affecting as many as one in eight women in their lifetime.

If caught early, it has a good chance of recovery, although treatment, like for any cancer, can be gruelling.

In recent years, scientists have begun researching if cannabis can have any benefit in treating cancer, or relieving symptoms caused by the disease or treatment for it.

While there are plenty of anecdotal reports, in which patients say cannabis has helped their symptoms or even stopped their cancer progressing, it is worth noting that to date there is no robust clinical evidence of the effectiveness of any cannabinoids in the treatment of cancer.

That said, some companies have been working on developing products which they suggest could help.

Two studies have been carried out by UK-based Apollon Formularies, which said in May that its medical cannabis formulations had been found to be effective at killing cells commonly found in breast cancer.

A combined treatment of medical cannabis and medicinal mushrooms was found to work by killing HER2+ breast cancer cells, which are the cause of around 20 per cent of all breast cancer cases.

The cannabis formulations were developed by the Jamaican subsidiary of Apollon Formularies, in partnership with Canadian firm Aion Therapeutic Inc. 

Testing showed that Apollon Jamaica’s medical cannabis was “particularly effective” in killing the living HER2+ cancer cells directly, while Aion’s medicinal mushroom formulations were most effective in stimulating the immune system’s T-cell production to attack and kill HER2+ cancer cells.

When the two formulations were combined, nearly 100 per cent of HER2+ breast cancer cells in 3D cell cultures were killed.

The next month, in June, Apollon also revealed that its proprietary medical cannabis formulations were successful in killing triple-negative breast cancer (TNBC) cells in 3D cell cultures, according to third party independent lab testing.

Metastatic TNBC is an aggressive form of breast cancer, with limited treatment options

It is thought to be up to 20 per cent of diagnosed breast cancers and accounts for approximately 200,000 cases each year around the world.

TNBC is more likely to affect younger people, those of African descent, Hispanics, and/or people with a BRCA1 gene mutation and is associated with a worse prognosis than other forms of breast cancer.

The testing results showed that medical cannabis formulations, developed by Apollon Formularies Jamaica, were effective in killing living TNBC cells directly, killing nearly 100 percent of the TNBC cells in 3D cell cultures.

Following the findings, Apollon began treating cancer patients with its proprietary medical cannabis products at the end of last year.

However, it’s important to note that these findings did not come from a peer-reviewed journal and more research is needed before cannabis widely available as a treatment.

Cannabis for symptom management

Where there is more promise is in the use of cannabis and even CBD, to help with symptom management and to ease the side effects of treatment.

Research has found that many breast cancer patients use CBD alongside their treatment – although they may not share this information with their medical teams.

Treatment for breast cancer includes options such as surgery, radiotherapy, chemotherapy and hormone therapy, many of which are accompanied by adverse effects such as pain, fatigue, nausea, insomnia and anxiety.

CBD works by interacting with the body’s natural endocannabinoid system, which is a complex network of receptors that regulates the daily body functions, such as inflammation, mood, and sleep.

Now, research has discovered that up to half of US adults with breast cancer use cannabis, alongside their cancer treatment, to manage their symptoms.

The study, which was published in the American Cancer Society journal, Cancer, last year, also found that many patients do not discuss their cannabis consumption with their doctors.

Researchers conducted an anonymous online survey to examine cannabis use among adults who had been diagnosed with breast cancer. 

The results revealed that out of the 612 participants, 42 per cent reported using cannabis to relieve symptoms such as pain, insomnia, anxiety, stress and nausea. Among those, 75 per cent said it was extremely helpful at relieving their symptoms while 79 per cent said they used it during treatment such as systemic therapies, radiation and surgery.

Almost half of the participants who consumed cannabis believed that it could be used to treat cancer itself, despite its effectiveness being unclear. Most participants also believed that cannabis products are safe.

Always speak to your doctor before making any changes to your medical care.