Recent advances in the management of hyponatremia in cancer patients

Hyponatremia is the most frequently encountered electrolyte disorder in cancer patients and is usually multifactorial in its origin. In this review, we discuss the predisposing factors, pathophysiology, clinical symptomatology, and currently available diagnostic and therapeutic options for the management of hyponatremia. In addition to paraneoplastic syndromes, concurrent chemotherapy and comorbidities predispose oncology patients to the risk of hyponatremia. Initial symptoms and signs can be subtle and the prompt evaluation and initiation of treatment is of paramount importance to prevent neurocognitive and other complications. The syndrome of inappropriate antidiuresis (SIAD) is the most common cause of hyponatremia, and the use of serum and urine parameters that distinguish SIAD from other etiologies is discussed. Individualized treatment is preferred depending on the underlying cause and severity of hyponatremia. The treatment of hyponatremia is reviewed and the importance of avoiding rapid overcorrection of the sodium level to reduce the risk of osmotic demyelination syndrome is emphasized. Vasopressin receptor antagonists (vaptans) offer a direct approach to the management of euvolemic and hypervolemic hyponatremia, but the indications for their use and long-term safety need to be clarified. The treatment of hyponatremia is likely to reduce complications and improve survival in cancer patients.