Hypercalcemia
Summary of Key Points
Incidence
• Hypercalcemia is a major metabolic complication associated with malignant disease.
• Hypercalcemia occurs in approximately 10% of patients with cancer.
• Hypercalcemia has a specific predilection for squamous carcinoma of the bronchus, carcinoma of the breast, and multiple myeloma.
• Hypercalcemia is frequently recognized late and managed poorly.
Etiology of Complication
• Parathyroid hormone–related protein (PTHrP) produces hormonal and paracrine effects.
• Factors released by, or in response to, metastases in bone (receptor activator of nuclear factor–κB ligand [RANKL], PTHrP, transforming growth factor-α, tumor necrosis factor, interleukin-1 [IL-1], IL-6, and others) cause paracrine effects.
• The final common pathway is osteoclastic bone resorption.
• It is aggravated by renal functional abnormalities or renal effects of PTHrP, or both.
Evaluation of the Patient
• Determination of the stage of disease and subsequent antineoplastic options provides a logical approach to management.
• Patient symptomatology is more relevant than the absolute calcium level.
• The total calcium concentration must be corrected for serum albumin concentration.
• Close attention to volume status and renal function are mandatory.
• Causes of hypercalcemia other than malignancy should be considered.
Treatment
• Antitumor therapy should be implemented for best long-term results.
• Consideration should be given to active palliation in the face of advanced disease when antitumor options are exhausted.
• Extracellular fluid volume should be expanded to induce a calciuresis.
