Hypomagnesemia in the Cancer Patient

Hypomagnesemia is a common medical problem that contributes to the morbidity and mortality of cancer patients. This review summarizes magnesium physiology and highlights the mechanisms underlying magnesium disturbances due to cancer and cancer treatment. The causes of hypomagnesemia can be categorized by the pathophysiological mechanism: decreased intake, transcellular shift, gastrointestinal losses, and kidney losses. Cancer patients are at risk for opportunistic infections, frequently experience cardiovascular complications, and often receive classes of medications that cause or exacerbate hypomagnesemia. Also, cancer-specific therapies are responsible for hypomagnesemia, including platinum-based chemotherapy, anti-EGFR monoclonal antibodies, human epidermal growth factor receptor-2 target inhibitors(HER2), and calcineurin inhibitors. Urinary indices, such as the fractional excretion of magnesium, can provide useful information about the etiology. The management of hypomagnesemia depends on the magnitude of hypomagnesemia and the underlying cause. We recommended checking serum magnesium at the beginning of treatment and as part of routine monitoring throughout cancer treatment. Opportunities exist for potential research and practice improvement, including further characterization of hypomagnesemia on the clinical impact on cancer outcomes, preventing hypomagnesemia in patients receiving high-risk anti-cancer agents, and developing effective therapeutic strategies.