Medical Marijuana: The Future of Breast Cancer Therapy

 Breast cancer is a disastrous disease that affects the lives of patients and families in all parts of the world.
Breast cancer remains the most common malignancy among Western women and accounts for 22.9% of all cancers in women across the globe. In 2008, breast cancer was reported as the cause of over 450,000 deaths worldwide.

Cannabinoids and Cancer

Breast cancer was the cause of 458,503 deaths worldwide (2008).

Although the medical properties of marijuana were first documented by human civilization over a thousand years ago, the therapeutic potential of cannabinoids – the medical compounds found in marijuana – in the treatment of cancer has only been discovered recently. Since the late 1990s, numerous preclinical studies have demonstrated the antitumor effects of cannabinoids in a variety of cancers.
Studies show that cannabinoid receptors are over-expressed in the tumor cells of certain cancers, such as cancers of the liver, lung, prostate and breast. Thus, researchers have been led to believe that the endocannabinoid system may be up-regulated in cancer in an innate biological effort to fight off this disease.
Studies also show that when cannabinoids are administered and bind to these receptors, they are able to inhibit cancer cell growth by preventing the proliferation of cancer cells and by inducing cancer cell death (apoptosis). Furthermore, cannabinoids have been found to impair both tumor angiogenesis – the increase in localized blood flow induced by tumor cells – and metastasis – the spreading of cancer to other organs.

Cannabinoids and Breast Cancer

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

Research suggests that 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 treatment of HER2-positive and triple-negative breast tumors. The therapeutic potential of cannabinoids is particularly important for patients with triple-negative breast cancer, as there is no standard therapy that currently exists and prognosis for this group of patients is poor.
In addition to their anti-cancer effects, research also shows that cannabinoids are considerably safer and less toxic than conventional treatments. Cannabinoids are non-toxic to non-tumor cells and are well tolerated by patients – only eliciting relatively mild side-effects such as dizziness and fatigue.

“This compound offers the hope of a non-toxic therapy that could achieve the same results without any of the painful side effects.” – Dr. Sean McAllister

In 2007, Dr. Sean McAllister and his team of researchers were one of the first to discover that CBD’s cancer-fighting properties could be successfully applied to breast cancer.
As it turns out, cannabinoids can provide a variety of other benefits in the treatment of cancer, including the prevention of nausea and vomiting associated with standard chemotherapeutic treatments and reduction of cancer-associated pain. Research also shows that, when combined with conventional cancer treatments, cannabinoids are able to induce a synergistic action against cancer and tumor cells, suggesting that the combination of conventional and cannabinoid-based treatments may more powerful than the administration of either treatment alone.

Clinical Applications: The Current State

Unfortunately, scientific research on the effects of cannabinoids on breast cancer has been limited to preclinical trials involving cell cultures and animal models. Researchers believe that further preclinical trials are necessary to identify which patient population is the most appropriate for cannabinoid treatment and which cannabinoids specifically present the best therapeutic option for patients before trials can advance to the clinical stage.
Until these factors are established, it is unlikely that oncologists will be willing to prescribe cannabinoid-based medicine for the treatment of breast cancer, despite the fact that research authors continue to assert the need for health professionals to be aware of cannabinoid research.
In a recent update (2013) published in the Oncology Nursing Forum, associate editor Susan Weiss Behrend concluded:

“…cannabinoids have demonstrated antitumor activity in preclinical breast cancer models. Practicing oncology professionals need to be aware of the clinical potential of these agents…” – Susan Weiss Behrend, RN

While medical marijuana remains inaccessible for most, cannabinoid-based pharmaceuticals such as Marinol and Cesamet (oral capsules of synthetic THC) are widely available to cancer patients for the treatment of chemotherapy-induced nausea. As well, Sativex (a natural-cannabinoid derived mouth spray) has been approved in Canada for the treatment of cancer-associated pain.
As modern cannabinoid research flourishes and continues to provide strong evidence of the cancer-fighting effects of these compounds, patients should remain optimistic about the future of cancer research and the emerging role of marijuana-based treatments that may one day take center stage in the battle against this devastating disease.