Drug therapy of hypercalcemia due to malignancy.

Abstract

Hypercalcemia is a serious complication of a number of malignant and benign disorders. The two most common causes of severe hypercalcemia are cancer and primary hyperparathyroidism. The differential diagnosis between cancer-related hypercalcemia and primary hyperparathyroidism is made by measuring intact parathyroid hormone (PTH). While most patients with primary hyperparathyroidism have elevated levels of intact PTH in their serum, in virtually all patients with hypercalcemia of malignancy the levels are suppressed (Blind et al. 1990; Nussbaum et al. 1987). Hypercalcemia in patients with cancer is usually due to secretion of parathyroid hormone-related protein (PTHrP) by the tumor. Assays for PTHrP are now available, and hypercalcemia of malignancy can be confirmed by an elevated level of serum PTHrP in the majority of patients (Blind et al. 1992). Other and rare causes of hypercalcemia of malignancy are the secretion of other bone-resorbing substances by the tumor, such as 1,25-dihydroxyvitamin D, or local effects of osteolytic bone metastases (Rosol and Capen 1992; Martin and Grill 1992). The clinical features of hypercalcemia can range from asymptomatic to severe intractable nausea and vomiting, dehydration, coma, and death. In general, the severity of the signs and symptoms is proportional to the degree of hypercalcemia and is also influenced by the degree of dehydration (Bajorunas 1990).KeywordsSerum CalciumPrimary HyperparathyroidismSerum Calcium LevelSerum Calcium ConcentrationSevere HypercalcemiaThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.