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breast cancer

What Science Says About Cannabis And Breast Cancer, The Most Common Cancer Among Women

The most common type of cancer among Canadian women is breast cancer. Ongoing research has attempted to show how cannabis compounds interact with cancer cells, and determine if certain cannabis derivatives are an effective treatment option for some breast cancer patients. 

CBD, the non-psychoactive cannabinoid in cannabis, is already being used to help control inflammation and modulate cancer progression. Medical cannabis is also recognized by the National Cancer Institute for its ability to provide relief from several symptoms often associated with cancer. These include, anxiety, pain, loss of appetite, nausea and vomiting. However, some controversy exists over the use of cannabis to help treat breast cancer, due in part to its unknown interaction with different cancer models. 

In cannabis, over 600 phytochemicals are known to be present. Phytochemicals are plant-produced compounds, with THC and CBD being the most active and most studied in cannabis. The way that THC and CBD fully affect the human body is not yet thoroughly understood, however current research indicates that cannabis may be used as additional anti-tumour therapy for breast cancer patients that are HER2 positive. There is also some evidence to suggest that whole flower phytochemicals create a stronger anti-tumour response than pure THC alone. 

CBD Shows Promise as a Supplementary Breast Cancer Treatment

Inflammation is thought to play a critical role in tumour progression. CBDA (the precursor to CBD) is thought to help control inflammation and prevent the migration of breast cancer cells. This could be why CBD is thought to possess anti-tumoural properties. Just last year in 2020, a study was published in the International Journal of Molecular Sciences demonstrating how CBD may be useful for cancer therapy. It reported that malignant cells that were exposed to CBD became more sensitive to standard cancer treatment, making the treatment more effective overall, while providing the therapeutic benefits of CBD in the process. 

However, even though CBD has been shown to have therapeutic benefits for cancer patients, some researchers would like to see more clinical evidence in support of using cannabis to treat cancer directly. It is important to note that cannabis compounds are still fairly understudied in terms of their molecular and pharmacological characteristics. In other words, there is much left to be discovered and understood, and the full benefits and pathways of using CBD to help treat breast cancer are still largely unknown. 

THC Exposure May Help, or Hinder

Just like CBD, medical THC is continuing to benefit from continued cannabis research. THC may provide strong anti-tumoural properties in some models of breast cancer, but in others it may actually increase their growth. In tumours that have little to no cannabinoid receptors, THC could increase growth by hampering the body’s anti-tumour immune system response. THC treatments also come with the potential for known side effects, such as increased anxiety and tachycardia, or speeding up of the heartrate. These vary in occurrence and severity between patients.

breast cancer
Stress fibres and microtubules in human breast cancer cells. Photo courtesy the National Health Institute.

However, THC does show promise at being able to help treat some models of breast cancer and many patient symptoms. It appears to be able to selectively target cancer cells, a necessary part of any cancer treatment. As mentioned earlier, it is also shown to have potential as a supplementary anti-tumour therapy for patients that are HER2 positive (cancer that tests positive for a protein called human epidermal growth factor receptor 2). 

While THC may provide strong anti-tumour properties in some cases, more research is required to accurately administer THC as a safe treatment for all types of breast cancer. In terms of hormone receptor-positive breast cancer patients, caution is advised regarding cannabis use, since their interaction is complex and understudied

Should I Take THC, CBD, or Both?

If you are a breast cancer patient, speak to your doctor and/or oncologist to ask if cannabis products are a possible treatment option, before attempting to self medicate. While shown to be helpful with uncomfortable side-effects such as nausea and pain, more research is needed before the full potential of CBD and THC can be uncovered, and it can be safely administered to the right patients for its anti-tumour properties. In the meantime, research has shown a promising direction for the use of cannabis products as a supplemental cancer treatment. It also shows significant promise in its ability to prevent the growth and spread of breast cancer tumours in some scenarios.