Is Medical Marijuana The Future Of Breast Cancer Therapy?

Breast cancer awareness

226,000 women in the US will be diagnosed with breast cancer this year.

Statistics show that breast cancer is the most common type of cancer among women and accounts for 22.9% of all cancers in women across the globe. In 2008 alone, over 450,000 affected women succumbed to the ominous disease.

Breast cancer and cannabinoids

The therapeutic potential of cannabinoids – the medical compounds found in marijuana – in the treatment of cancer has only been discovered lately. Numerous preclinical studies have demonstrated the antitumor effects of cannabinoids in a variety of cancers since the late 1990s.

A number of studies have shown that cannabinoid receptors are over-expressed in the tumor cells in certain organs such as liver, lung, prostate and breast cancers. Thus, scholars have been led to assume that the endocannabinoid system may be up-regulated in cancer in an intrinsic biological effort to resist this disease.

The same studies also show that when cannabinoids bind to these receptors after administration, they are able to inhibit cancer cell growth by preventing the proliferation of cancer cells and by inducing cancer cell death (apoptosis). Moreover, these compounds impair both tumor angiogenesis (the increase in localized blood flow induced by tumor cells) and metastasis (the spreading of cancerous cells to other organs).

Breast cancer and cannabinoids

Great medical advancements in breast cancer treatment have been made in recent decades, but certain breast tumors continue to be resistant to conventional chemotherapy. Breast cancer is comprised of tumors that are distinct in their molecular profiles, leading medical professionals to categorize the disease into 3 main subtypes.

Synthetic cannabinoids and phytocannabinoids (mainly THC and CBD) may be useful in treating all 3 subtypes of breast cancer (with the strongest evidence of therapeutic potential pointing to the treatment of HER2-positive and triple-negative breast tumors). The therapeutic capacity of cannabinoids is particularly important for patients with triple-negative breast cancer as there is no standard therapy that is currently in use.

Research also shows that cannabinoids are considerably safer and less toxic than conventional curative treatments. Cannabinoids are non-toxic to healthy cells and produce only mild side-effects such as vertigo and fatigue.
In 2007, Dr.Sean McAllister and his team pioneered an effort which showed that CBD’s cancer-fighting properties could be successfully applied to breast cancer:  “This compound offers the hope of a non-toxic therapy that could achieve the same results without any of the painful side effects,” says Dr. Sean McAllister.

When combined with conventional cancer treatments, cannabinoids are able to induce a synergistic action against cancer cells, suggesting that the combination of conventional and cannabinoid-based treatments may be more powerful than the administration of either treatment alone.

Clinical applications

Scientific research on the effects of cannabinoids on breast cancer has been limited to preclinical trials consisting of cell cultures and animal models. Researchers believe that further preclinical trials are necessary to identify which patients are the most suitable for treatment with cannabinoids and which cannabinoids specifically present the best therapeutic option for patients before trials can continue to the clinical stage.

Until these factors are well-established, it is unlikely that oncologists will be willing to prescribe cannabinoid-based therapy for their patients, despite the fact that research authors continue to assert the need for health professionals to be respective of cannabinoid research results.

In the update of 2013, published in the Oncology Nursing Forum, associate editor Susan Weiss Behrend concluded:
“…cannabinoids have demonstrated anti tumor activity in preclinical breast cancer models. Practicing oncology professionals need to be aware of the clinical potential of these agents…

The good thing is that cannabinoid-based drugs such as marinol and cesamet (oral capsules of synthetic THC) are widely available to cancer patients for the treatment of chemotherapy-induced nausea.
Sativex (a natural-cannabinoid derived mouth spray) has been approved in Canada for the treatment of cancer-associated pain, as well.

As present cannabinoid research flourishes and continues to give strong evidence of the cancer-fighting power of these compounds, patients should remain optimistic about the future of cancer research and the emerging part of marijuana-based treatments which soon may take up the central position in the cancer battlefield.  

Sources:
http://mainecancer.org/
http://news.bbc.co.uk/
http://www.ncbi.nlm.nih.gov