Hypercalcemia in malignant disease.

Hypercalcemia is a common and serious complication of neoplastic disease. It may occur in association with a variety of tumors and usually indicates a lack of tumor control. Early symptoms are nonspecific, involving several organ systems in a syndrome that may progress rapidly to death. The pathophysiology of hypercalcemia is complex and not fully understood. Research continues on local mechanisms of bone destruction at sites of bone metastases and the identification of humoral tumor-derived osteolytic factors. The therapeutic approach to hypercalcemia should be sequential, dictated more by clinical symptoms than by absolute calcium levels. The diversity of measures and agents used in the therapy of hypercalcemia of malignancy reflects the multiple mechanisms involved. The therapeutic maneuvers outlined usually yield temporary success and must be accompanied by specific antitumor therapy, the ultimate treatment for the hypercalcemia of neoplastic disease.