Preventing ovarian cancer with cannabis

By University of Ottawa

Faculty of Health Sciences, Camille Cottais

Research
Faculty of Health Sciences
Research and innovation
Hands holding a drawing of the female reproductive system and the ovarian cancer ribbon
What if cannabis could prevent and treat one of the most feared cancers in women? The legalization of cannabis in Canada in 2018 led to cannabidiol, or CBD, being increasingly used in modern medicine. A molecule found in cannabis, CBD is used, among other things, to relieve chronic pain and alleviate anxiety and insomnia. However, its therapeutic use could also extend to pathologies such as cancers and hormonal disorders.

David Landry is an assistant professor at the Interdisciplinary School of Health Sciences. He is a member of the Pekuakamiulnuatsh First Nation community of Mashteuiatsh, an Acadian from New Brunswick and a member of LIFE Research Institute. In a new research proposal, he looks into the negative effects of cannabis on fertility and human development, but also at how the CBD molecule can be used to treat polycystic ovary syndrome (PCOS) and prevent the development of ovarian fibrosis and ovarian cancers. 

Professor David Landry

CBD and hormone production

Cannabis is composed of two main molecules: tetrahydrocannabinol (THC), which causes psychoactive effects such as euphoria, and cannabidiol (CBD), whose properties are more relaxing and soothing. Landry says that unlike THC, CBD has no psychoactive effects, is not addictive and is very well tolerated in humans.

However, the CBD molecule acts on the intrinsic receptors in the body, notably those involved in women’s fertility. According to Landry, “more than 50% of women of reproductive age have used cannabis in the last 30 days. But cannabis is said to have a harmful effect on sex hormone production in women, and therefore on their fertility.” Frequent cannabis use can therefore contribute to infertility, which, according to Landry, is becoming more prevalent, currently affecting 10% to 15% of Canadian couples, a number that keeps rising.

However, this negative effect can be beneficial in the case of pathologies that cause excess hormones, such as polycystic ovary syndrome, a hormonal disorder that affects 8% to 13% of women, according to the World Health Organization. CBD could help reduce hormone production in women with this syndrome.

“While very common in women of reproductive age, PCOS is a complex and under-recognized condition,” says Landry. “Two of these three symptoms need to be present for a diagnosis to be made: overproduction of male hormones (hyperandrogenism), irregular menstrual periods and more than 10 follicles per ovary. PCOS can cause ovarian cysts, hirsutism, acne, obesity and repeated miscarriages. It is the leading cause of infertility in women, affecting around one in 10.” Given these health challenges, potential new therapeutic solutions, such as CBD and its synthetic derivatives, are worth looking into. 

An unexpected ally in the fight against ovarian cancer

In addition to studying the effect of cannabis on hormone production, Landry is interested in how CBD affects the development and progression of ovarian cancers. This molecule could reduce the proliferation of ovarian cancer cells and even make chemotherapy-resistant cells responsive to chemotherapy drugs. This is called “a chemosensitization process. That is, a cancer cell becomes more responsive to chemotherapy after being treated with CBD,” Landry explains.

Landry says that CBD is now frequently used to alleviate chemotherapy symptoms, to reduce the risk of fainting, for example. However, his study could demonstrate the benefits of CBD in reducing the concentration of chemotherapy drugs or targeting treatment-resistant cancer cells. Indeed, cancer cells that are not killed often fall dormant, “reawakening” a few years later, leading to a relapse.

While trials have not yet been conducted, the preliminary data are promising, according to Landry. They already show that CBD has a positive effect on chemosensitization and reduction of cancer cell proliferation, thus opening up new treatment avenues. This has not yet been proven for ovarian cancer, however. 

Preclinical trials on mice

To test his research hypotheses, Landry plans to carry out in vitro tests with cancer cell lines, and then in vivo tests on mice. After ovarian cancer is simulated in the mice, they will be treated with different doses of CBD and chemotherapy drugs. They will be encouraged to ingest the cannabis orally, which will be mixed with Jell-O.

Professor David Landry doing experiment in a lab

If the results are encouraging, clinical studies can then be conducted on humans. According to Landry, it can be difficult to apply research findings from mice to humans: “Just because something works on mice does not mean that it will work on people. Humans have many genetic variations, whereas mice are all genetically identical.” Just as with the development of any other drug, there is always a risk.

If Landry’s research is conclusive, the findings could represent a significant advance in the fight against ovarian cancer, giving new hope to millions of patients. However, he cautions that therapeutic use of CBD must be done responsibly and under medical supervision.