Cures marijuana tumors


From Dr. Manuel Guzman

Cannabinoids, the active components of cannabis, and their derivatives have soothing properties in cancer patients by preventing nausea, vomiting and pain, and by increasing appetite. In addition, these substances inhibit the growth of tumor cells in laboratory animals - mice and rats. However, there is currently no reliable evidence that cannabinoids - natural or synthetic - are effective at curing cancer in patients, despite research in this area.

Comprehensible overviews - including the indication of scientific literature - on cannabinoids and cancer can be found on the website of Cancer Research UK and on the website of the National Cancer Institute of the USA. This information is summarized and discussed below.

What is cancer
Cancer is a broader term used to describe diseases in which cells divide without control and can generally invade other tissues. Cancer is not just one disease, it is many diseases: More than 100 different types of cancer are described by the World Health Organization in terms of their tissue characteristics, and there are probably hundreds, if not thousands, of cancers when viewed in terms of their molecular and genetic profiles.

What are the most common types of cancer?
Most cancers are named for the organ or cell types in which they start. In addition, cancers are generally grouped into the following larger categories:
- Carcinoma: cancer that begins in the skin or tissues that line or cover internal organs.
- Sarcoma: cancer that starts in bones, cartilage, fat, muscles, blood vessels or other connective or supporting tissues.
- Leukemia: cancer that starts in tissues that produce blood, such as bone marrow, and results in the production of large numbers of abnormal blood cells that are then found in the blood.
- Lymphoma and myeloma: cancer that starts in cells of the immune system.
- Central nervous system cancers: cancer that starts in tissues of the brain and spinal cord.

Do cannabinoids inhibit cancer growth?
Almost all research on cannabinoids and cancer cells has so far been carried out with cancer cells grown in the laboratory and on animal models. Many scientific studies have reported that various cannabinoids (both natural and synthetic) have a wide range of growth-inhibiting effects on cancer cells. These include:
- The initiation of cell death by a mechanism called apoptosis.
- The interruption of cell division.
- Preventing the formation of new blood vessels in tumors - the process of new blood vessels forming is called angiogenesis.
- Reducing the ability of cancer cells to form daughter tumors in the body by preventing cells from moving or invading neighboring tissues.
- The acceleration of the cell's internal "waste deposit machine" - a process known as autophagy - which can lead to cell death.

In summary, cannabinoids are effective substances to treat at least some cancers in laboratory animals - mice and rats.

Do cannabinoids inhibit cancer growth? (Anecdotal evidence in humans)
As mentioned above, almost all research to investigate whether cannabinoids can treat cancer has been done in the laboratory. It is therefore important to be very careful when translating these results into patients. These are much more complex than a petri dish or a mouse. Anecdotal findings on cannabis use have historically been helpful in providing clues about biological processes controlled by the endocannabinoid system and the potential therapeutic benefits of cannabinoids. In the specific case of cancer, there are videos and reports on the Internet arguing that cannabis can cure cancer. This anecdotal evidence is - at least so far - extremely weak and unclear.
Here are a few examples that contribute to the lack of clarity:
- We do not know whether the (assumed) effect of cannabis is based on a placebo effect.
- We do not know whether the tumor has stopped growing for natural / endogenous reasons - some tumors disappear spontaneously due to the body's defenses against tumors.
- We do not know how many patients have used cannabis and have received no therapeutic benefit. We therefore do not know the (assumed) effectiveness of a therapy based on cannabis.
- Since most patients presumably received standard therapy before or at the same time as using cannabis, we do not know whether the (assumed) effects of cannabis were in fact based - at least in part - on standard therapy, possibly reinforced by cannabis. But we have no proof.
- We do not know the individual parameters of tumor growth that were monitored and how long the patient was monitored. Many of the potentially beneficial effects of anticancer agents (or, in this case, cannabis) are short-term effects. But what about long-term survival without tumor growth and overall survival?
- Cancer is a very heterogeneous disease of different types and no one has brought together a large enough number of patients with any particular cancer to support the notion that cannabinoids are effective in that specific cancer.

In summary, while it is possible that cannabis preparations may have some anti-cancer activity in some specific cancer patients, the anecdotal evidence to date is very weak and, unfortunately, far from supporting the assumption that cannabinoids are effective cancer drugs for patients.

Do cannabinoids inhibit cancer growth? (Clinical research)
To date, results have only been published from one phase I clinical trial investigating whether cannabinoids can treat cancer in patients. Nine patients with advanced glioblastoma multiforme - an aggressive brain tumor - who had previously not responded to standard therapy, were given highly purified THC directly into their brains via a catheter. Under these conditions, cannabinoid administration was safe and could be achieved without any relevant undesirable effects. While no statistically significant conclusions can be drawn from this small group of patients treated without a control group, it can be said that the results obtained suggest that some patients responded to THC therapy with a reduced rate of tumor growth - at least in part. This could be proven with imaging methods and the analysis of biomarkers. These results have been encouraging and increase interest in the potential uses of cannabinoids in cancer therapy. However, they also highlight the need for further research aimed at optimizing cannabinoid use in terms of patient selection, combination with other cancer drugs, and the use of other routes of ingestion.

Overall, there are many unanswered questions related to the potential of cannabinoids to be used as anticancer agents, and it is necessary and desirable that extensive clinical studies be conducted to determine how cannabinoids, beyond their palliative effects, are used in the treatment of cancer patients can.

About the author
Dr. Manuel Guzman is Professor in the Department of Biochemistry and Molecular Biology at Complutense University of Madrid (Spain). He coordinates the group on cannabinoid signaling.