[The significance of early diagnosis of cancer-related hypercalcaemia]

Cancer-related hypercalcaemia is one of the most common life-threatening metabolic disorders. It occurs in 20% to 30% of patients with cancer during the course of the disease, which depends on tumour type, too. There are two types of cancer-related hypercalcemia: humoral hypercalcemia and local osteolytic hypercalcaemia. Malignant hypercalcaemia is mediated by several circulating factors secreted by malignant cells. The biological actions of these factors are primarily stimulation of osteoclasts to resorb bone and, secondly, stimulation of calcium reabsorption at the renal tubules resulting in an elevation of serum calcium level. Diagnosis of hypercalcaemia is relatively difficult due to the non-specific clinical signs as well as the underlying malignancy and the side-effects of palliative medical treatment. Consequently, cancer-related hypercalcaemia is underdiagnosed quite often. Unrecognised malignant hypercalcaemia can lead to death. Nowadays 90% of hypercalcaemia can be treated with administration of intravenous saline containing fluids and bisphosphonates. Literature data suggest that hypercalcaemia is treated in less than 40% of hospitalized patients properly due to diagnostic errors and mismanagement.