A hospital survey of hypocalcemia in patients with malignant disease.

Hypocalcemia was found in 122 (1.6%) of the patients attending a large oncological center. In 10% of the cases, hypocalcemia was caused by hypoparathyroidism and/or uremia, in 12% it was related to a major infection. Osteoblastic metastases were responsible in 4% of the cases and in 74% hypocalcemia accompanied an impairment of the general condition due to the malignancy or its treatment, usually in the terminal stage of the disease. The most common cause of hypocalcemia in this group of patients seemed to be hypoproteinemia. Correction of serum calcium for variations in serum albumin concentration, however, indicated that a small proportion had a decreased ionized calcium value as well, the mechanism of which remained obscure. The hypocalcemia was usually relatively mild, especially after correction for albumin variations. Tetanic symptoms were not seen. Hypocalcemia thus seems to be a fairly common complication of malignant disease, the clinical relevance of which, however, appears to be relatively small in most cases.