Despite intensive research efforts, it has still not been possible to determine the exact causes of cancer. It is assumed that numerous risk factors have an impact on the development of cancer. In some cases, genetic triggers are hidden behind a cancer disease. However, the lifestyle of affected individuals is also important. The most important risk factors include: 

• a genetic predisposition
• an unhealthy diet, such as eating too much red meat, an increased consumption of alcohol, and a lack of fiber, fruits and vegetables, which increases the risk of cancer in the gastrointestinal region
• tobacco consumption, which may be responsible for the development of lung cancer or cancers of the respiratory tract
• ionizing radiation such as X-rays, radon radiation or radiation accidents
• environmental toxins
• intense UV radiation, which can trigger skin cancer
• certain infections such as HPV infections (human papillomaviruses) or hepatitis B infections 

For cancer patients, the effect of cannabis seems particularly promising: It helps against disease-related complaints and side effects of chemotherapy. Thus, cannabis can promote the quality of life of cancer patients and facilitate the therapy. In addition, there is evidence that cannabinoids even fight cancer cells and inhibit their growth. In the following, we take a closer look at how cannabis can be used in cancer.

All known chemotherapeutic agents damage fast-growing tissues, resulting in the familiar side effects such as hair loss, nausea, damage to blood formation, etc. The cannabinoids tetrahydrocannabinol (THC) and cannabidiol (CBD), the most important ingredients of the cannabis plant, on the other hand, spare healthy cells and act specifically against cancer cells. Although there has been evidence of cancer inhibition by cannabis since the 1990s – cannabis smokers had significantly less lung cancer than would have been expected from the pollutants in the smoke – the potential to fight cancer has only been discovered in recent years. Now it is being intensively researched worldwide.

To date, several studies have been conducted that demonstrate the positive effects of cannabinoids in combating the growth of cancer cells and inducing their death through a process known as apoptosis. A 2009 study showed that THC inhibited the growth of certain brain cancer cells. A 2013 study showed how CBD can also affect these cells. In 2015, cannabinoids were also shown to be effective in inducing cell death from skin cancer. A 2011 study that came to similar conclusions in breast cancer.