​​How medical cannabis may be of benefit to breast cancer patients

Breast cancer awareness

Breast Cancer Awareness Month is an international health campaign which takes place every October. Since its launch in 1985, it has aimed to raise awareness of breast screening, early diagnosis and prevention. 

There are many different ways you can get involved with the campaign, such as by wearing pink on 18th October to raise funds for Breast Cancer Now, or taking on an exercise-based challenge for Breast Cancer UK.

How common is breast cancer?

Breast cancer is the most common form of cancer diagnosed in women globally, affecting around two million women every year. It can occur in every country of the world at any age after puberty, but, the risk of developing breast cancer increases later in life. According to the World Health Organization, approximately 0.5–1% of breast cancers occur in men.

In the UK, breast cancer is the most common form of cancer, with 56,800 new cases diagnosed every year. Since the early 1990s, breast cancer incidence rates have increased by around 18%. However, in the last 50 years, survival rates have doubled. 

Today, Cancer Research estimates that almost 8 in 10 women diagnosed with breast cancer are predicted to survive for at least 10 years.

Types of breast cancer 

There are several different types of breast cancer. Most types are ‘invasive’, which means they may spread to other areas of the body. Non-invasive breast cancer has not yet developed the ability to spread.

Some of the more common types of breast cancer include:

• Ductal carcinoma in situ (DCIS)
• Invasive breast cancer no special type (NST)
• Invasive lobular breast cancer 
• Inflammatory breast cancer 
• Paget’s disease of the breast

Secondary breast cancer 

This year, the Breast Cancer Awareness Month is focused on raising awareness of secondary (or metastatic) breast cancer, which affects around 61,000 people in the UK. This term is used when the cancer has spread to another part of the body, such as the liver, lungs, brain, or bones.

Breast cancer symptoms

As well as being aware of the symptoms of breast cancer, women should also carry out regular self-examinations to get to know what is normal for their breasts. This ensures any changes or abnormalities can be detected at the earliest stages.

According to the NHS, symptoms of breast cancer in women may include:

• a lump or swelling in your breast, chest, or armpit
• a change in the skin of your breast, such as dimpling or redness (which may be harder to see on black or brown skin)
• a change in size or shape of breasts
• nipple discharge (if you are not pregnant or breastfeeding), which may have blood in it
• a change in the shape or look of your nipple, such as it turning inwards or a rash on it (which may look like eczema)
• pain in your breast or armpit which does not go away – breast pain that comes and goes is usually not a symptom of breast cancer

Symptoms of secondary breast cancer depend on where in the body the cancer has spread to, but they are often similar to those of other conditions such as: 

• Feeling constantly tired
• Constant nausea (feeling sick)
• Unexplained weight loss and loss of appetite

Breast Cancer Now recommends speaking to your GP or breast nurse if you have any symptoms which are new, don’t have an obvious cause, and don’t go away.

Breast cancer care

The main treatments for breast cancer include surgery, chemotherapy, radiotherapy and hormone therapy. A patient’s medical team will decide on the best treatment based on a variety of factors, such as how big it is, whether it has spread, whether the cancer cells have certain proteins (receptors), and general health. 

Being diagnosed and undergoing treatment for breast cancer can be a worrying time. Alongside medical treatment there are places you can go to find support, including charities such as Breast Cancer Now, Macmillan Cancer Support, Cancer Research UK and Marie Curie.

Medical cannabis and cancer

There is a lot of misinformation out there when it comes to cannabis and cancer, which can be confusing and overwhelming at a difficult time. Many patients have shared how cannabis has helped them during their cancer journey. However, it is important to note that to date there is no robust clinical evidence of the effectiveness of cannabis in the treatment of breast cancer. 

In the UK, medical cannabis may be prescribed as part of your wider treatment plan when conventional methods have proven to be ineffective at managing specific symptoms such as pain and anxiety. 

Some people also find it helpful for mitigating the side-effects of first-line treatments such as chemotherapy and radiotherapy, which can be aggressive. Nabilone is a licensed cannabis-based medicine which is prescribed through the NHS for chemotherapy-induced nausea and vomiting, but other cannabis-based options are available at Releaf. 

What does the research say?

In 2022, Cancer Research UK updated its guidance on cannabis and cancer treatment, stating that studies have delivered “intriguing results from lab experiments looking at a number of different cancers, including glioblastoma brain tumours, prostate, breast, lung, and pancreatic cancers.”

But while some promising early studies are investigating the role of medical cannabis in can cancer, more research is required to understand the role of different cannabinoids in different cancer types. 

There is more substantive evidence for the use of cannabis in mitigating the side-effects of conventional treatments, particularly chemotherapy-induced nausea and vomiting (CVN) and chemotherapy-induced peripheral neuropathy (CIPN).

One clinical trial investigating cannabis in the treatment of CVN found that both cannabis and a placebo produced similar results, with the vast majority (83%) of people surveyed preferring cannabis. Elsewhere, analysis found a significant difference in CIPN between cannabis-exposed patients (15.3%)  and controls (27.9%).

The results of a multi-centre registry study, published in 2023 also suggested that when used as a complementary cancer therapy, medical cannabis could safely relieve pain, while curbing the consumption of opioids and other pharmaceuticals, and improving sleep. And a comprehensive assessment of the benefits of medical cannabis for cancer-related pain found that most patients surveyed experienced significantly less discomfort while using medical cannabis, as well as a decrease in other cancer-related symptoms.

What the experts say

We also spoke to our very own Dr Sue Clenton, Releaf’s Medical Director, and an Oncologist with over 20 years of experience. Dr Clenton said: 

“Like many cancer types, breast cancer and its associated symptoms, as well as the conventional approaches used to treat it, can significantly disrupt a person’s day-to-day life. Chronic pain, sleep disturbances, appetite changes, and low moods can all contribute to a decline in overall wellbeing and quality of life. 

While medical cannabis is in no way a cure for breast cancer, it has shown promising results in helping to manage these symptoms, and as an Oncologist - I’ve seen first-hand how regaining control over these symptoms can make a remarkable difference in a patient’s life.”

Is cannabis safe for cancer patients?

There is not enough evidence to say for sure how safe and/or effective cannabis is in the treatment of cancer because of the large amount of variables involved in each individuals' health, and, due to the variety of cannabis-based medicines available. 

It is always important to have an open discussion with qualified health professionals when considering a new treatment option before making any changes or incorporating medical cannabis into your treatment plan, and Releaf’s clinical team is here to help. 

Medical cannabis is a very personalised treatment, affecting everyone differently, so Releaf’s doctors tailor their treatment plans to the individual to ensure it is suitable for your needs.