Micke O1, Büntzel J2, Hunger R3, Mücke R4, Kisters K5

1 Franziskus Hospital, Klinik für Strahlentherapie und Radioonkologie, Bielefeld
2 Südharzkrankenhaus, Klinik für Hals-, Nasen- und Ohrenheilkunde, Nordhausen
3 Lürlibadstr. 80, Chur, Schweiz
4 Klinikum Lippe, Strahlen-therapeutische Klinik, Lemgo
5 St. Anna Hospital, Medizinische Klinik I, Herne

Oncology had not paid much attention to the electrolyte magnesium so far. However it plays an important role in numerous physiological and pathophysiological processes, e.g. in anticancerogenesis, regulation DNA- and RNA synthesis, mitosis, metastisation, nuclear repair mechanisms, and apoptosis. Therefore, magnesium definitely earns far more medical interest. In particular, in oncological therapies negatively influencing renal function, as cisplatinum, severe hypomagnesaemias can occur, as shown by own studies, which often requiring treatment. A new aspect arose from the introduction of the epidermal growth factor receptor (EGFR) antibodies cetuximab and panitumumab in the oncological therapy, particularly in colorectal cancers. These lead by an interaction with the transient receptor potential cation channel TRPM6 in the majority of patients to a clinical hypomagnesaemia and in up to 10% to 36% of cases to severe Grad III/IV hypomagnesaemias. Thereby, interestingly it appeared that that there is a significant positive correlation between hypomagnesaemia clinical response to the antibody therapy as well was to a significantly better survival. The underlying mechanism is nearly unknown, but maybe similar factors, as we postulated in hypomagnesaemia and radiotherapy, for example the inhibition of DNA repair in tumor cells. Therefore, under special circumstances a low magnesium level may be more useful for tumor patients. Another exciting aspect of magnesium is the treatment of hot flashes due to hormonal deprivation therapy. Magnesium is known for its neuro- and vasoactive effects. Even though there are uncountable hints in the internet on the treatment of hot flashes with magnesium – the digital search engine Google alone yields more than 253,000 hits -, only two smaller scientific studies on this topic have been carried out so far. So far, there are only some small clinical studies and few case reports on this topic. In an own pilot study with 6 patients suffering from breast cancer and hot flashes under hormonal deprivation were treated with 300 to 600 mg magnesium orally over 4 to 6 weeks. In 5/6 (83%) of patients a marked improvement of symptoms was observed. Thereby the strength as well as the frequency of hot flashes was alleviated significantly. As side effects, only in one case stronger diarrhoea was observed. The exact biological mechanism of magnesium action is not yet elucidated. Recent studies from literature support our findings. In the light auf the recent study data, magnesium remains a highly interesting ion for oncology, whose different facets should be more enlighted.