Marijuana (Latin Cannabis) is a common name for several related plant species, which differ among others in the content of biological agents, called cannabinoids. Certain varieties of đ these substances have been used in medicine for many millennia, others for making textiles. The first records go back to the Chinese Emperor Chen Nun, who reigned 5,000 years ago! The therapeutic effect is primarily related to the central nervous system, where the receptors for both main forms are cannabinoids, i.e. tetrahydrocabaninol (THC) and cannabidiol (CBD) are most abundant. In addition to influencing nerve cells, they also affect the immune system and various types of cancer cells that also express more receptors than normal cells.

For more than a decade, the Department of Genetic Toxicology and Cancer Biology has been studying brain tumours - glioblastoma, one of the most aggressive cancer of the central nervous system with an average patients’ survival of about a year and a half. It is therefore not surprising that this cancer is most studied among cancer types regarding the effect of cannabinoids, and mostly in animal models in vivo. However, in vitro, mechanisms of action and possible treatment modalities of this tumor is investigated in the primary cells cultures from from patients’ tumours. Preliminary results show extraordinary effects, depending though on the nature of the tumor itself, that we may be able to reveal at the end of this study. The purpose of this research, financed by a private pharmaceutical company SigmaPlus Ltd is to achieve a personalized approach in the cannabinoids treatment of individual subtypes of cancers/patients.

A recent review of glioblastoma treatment by cannabinoids, published in Journal if Neuro-oncology (by Likmar and Nagler, 2018) indicates a decrease in tumours from 50 to 95% or even a complete macroscopic disappearance of the tumor mass. This is a good basis for the initiation of clinical studies, which are scarce and thus Slovenian oncologists would be hesitant to initiate one such study on cannabinoid adjuvant treatment. Unfortunately, I can only say that at present, there is only one larger on-going registered international study, indicating an extension ofan clinics in respect to collaboration.

Recently, Slovenian oncologist dr. Josipina Ana Červek published in Pharmaceutical Journal (2016, 67) that "cannabinoids in oncology have two potential roles: as a remedy for the treatment of symptoms and as an anti-tumor medicine. Cannabinoids relieve more symptoms of malignant disease and thus improve the quality of life. They are not the first choice therapeutics, but they achieve the greatest benefit as a supplement to standard medicines. A combination of THC and CBD is recommended as this has a better therapeutic effect and less adverse effects than any cannabinoid alone. At the Institute of Oncology these patients are prescribed cannabinoids for symptomatic treatment, when there are more difficult control symptoms and / or more symptoms at the same time as an add-on to standard therapy ", concluded Dr. Červek.

In Slovenia by the change of legislation in 2014, partial use of cannabinoids for medical palliative purposes was allowed only to alleviate the symptoms of the disease and "chemotherapies". There are still some confusion about prescribing the cannabinods, as there is a serious shortage of knowledge and information among doctors and other health professionals in this field.

Therefore, I can conclude that cannabinoids in oncology and medicine generally show therapeutic potential, and we would need to continue to do pre-clinical, as well clinical research in our country, not only in the neighbouring Austria, or even Croatia, where these research is well overtaking ours.

Link to video clip - ORF1: http://tvthek.orf.at/profile/Newton/1306.

Prof. Dr Tamara Lah Turnšek