The evaluation of serum magnesium and calcium/magnesium ratio in patients with breast cancer receiving adjuvant chemotherapy.

Background: Magnesium (Mg) deficiency may promote tumor growth and metastasis, hence the need to monitor and possibly normalize its level during treatment is emphasized. Therefore, our study aimed to assess the effect of a six-week adjuvant chemotherapy on serum Mg and calcium (Ca)/Mg ratio in patients with breast cancer. Materials and methods: The study included a group of 80 women with breast cancer who were qualified for adjuvant chemotherapy in the AC regimen (doxorubicin and cyclophosphamide). Serum magnesium and calcium levels were determined spectrophotometrically. Serum high-sensitivity C-reactive protein (hs-CRP) was measured using enzyme-linked immunosorbent assay (ELISA). Results: In the postoperative period, decreased serum magnesium and increased Ca/Mg ratio were observed in breast cancer women compared to healthy controls. After six weeks of AC chemotherapy, magnesium levels increased significantly, reaching a lower reference value. The same trend was noticed for the Ca/Mg ratio, which increased slightly but remained higher than in the control group. In patients with higher values of hs-CRP after treatment, decreased serum magnesium level was observed. Conclusions: Our study showed that the postoperative period is associated with magnesium deficiency in breast cancer patients. However, AC chemotherapy tends to normalize its concentration. During treatment, low magnesium concentration was associated with increased hs-CRP levels. This finding confirms that magnesium deficiency may induce inflammation, which has been implicated in tumor growth and metastasis. However, further research is needed to explain the role of magnesium in tumor development clearly.