Hypocalcemia — An Unusual Metabolic Complication of Breast Cancer

Abstract

HYPOCALCEMIA as a complication of metastatic cancer is rare. It has been reported as occurring spontaneously in lung cancer,¹ in response to successful treatment of carcinoma of the prostate^{2 , 3} and in chronic leukemia,⁴ but has seldom been noted in breast cancer.⁵ Hypercalcemia, however, is common in breast cancer^{6 , 7} and appears to be variable in etiology, pathogenesis and prognostic significance.^{8 , 9} Recent reports of hypercalcemia that occurred in the absence of metastatic bony involvement suggest the secretion of a parathormone-like substance by the tumor.¹⁰ The secretion of a thyrocalcitonin-like¹¹ substance by tumors is an intriguing alternate possibility but has not been described . . .