Effects of streptozotocin on an islet cell carcinoma with hypercalcemia

A 57 year old man had an inoperable pancreatic islet cell carcinoma with liver metastases. Biochemical studies indicated the possibility of a circulating parathyroid hormone-like substance; exploration of the neck revealed normal parathyroid glands. Biochemical studies of family members revealed no evidence of familial endocrine adenomatosis. The patient's hypercalcemia could not be controlled with the usual calcium lowering measures. He was treated with streptozotocin, with temporary increases in his hypercalcemia after each of the first three treatments. After four doses of streptozotocin, the size of the tumor decreased and the serum calcium fell to hypocalcemic levels. The serum calcium subsequently stabilized at low normal levels, and the tumor has remained in partial remission for 14 months after administration of the last dose of streptozotocin.