Hypercalcemia in cancer patients: pathobiology and management

Hypercalcemia is the most common life-threatening metabolic disorder associated with cancer, occurring in approximately 10-30% of all patients with neoplastic disease, although it occurs much less often in the pediatric setting. Hypercalcemia can emerge in hematologic malignancies, particularly multiple myeloma, as well as assorted solid tumors, primarily lung and breast cancers, and can even dominate the clinical picture in select patients. Early diagnosis and treatment with fluids and drugs that lower calcium levels in the blood can improve symptoms in a few days, ameliorate the quality of life of these patients, and avoid delays in the implementation of further anticancer treatments. Occasionally, the symptoms of hypercalcemia can appear gradually, and may be non-specific, resembling symptoms of many cancers and other comorbidities, especially in the elderly, thus resulting in an underestimated incidence of hypercalcemia in cancer patients. Of note, there is an increasing number of antineoplastic compounds that can interfere with calcium metabolism. Taking into consideration both the severity of hypercalcemia and the tumor status, health care providers should determine and apply appropriate treatment measures. We provide a comprehensive subjective synthesis of peer-reviewed evidence on the pathophysiology and treatment of hypercalcemia in cancer patients.