Combined therapies with calcitonin and corticosteroids, or bisphosphonate, for treatment of hypercalcemia of malignancy

Abstract

Thirty-four patients with hypercalcemia of malignancy were studied in three randomized prospective clinical studies. In study 1, 10 patients with solid tumors and in study 2, 10 patients with multiple myeloma, received calcitonin alone or combined calcitonin and corticosteroids. In study 3, 14 hypercalcemic patients with solid tumors received either pamidronate alone or pamidronate and calcitonin. Patients with solid tumors had at least one bony metastasis at the time of the study. Serum immunoreactive parathyroid hormone (PTH) levels in all patients were either undetectable or below the lower limit of the normal range, suggesting that the hypercalcemia is secondary to malignancy and not caused by an underlying primary hyperparathyroidism. The calciumlowering effect of calcitonin was rapid, but disappeared in 3–4 days. Corticosteroids significantly prolonged the duration of normocalcemia in patients with hematological malignancies but not in patients with solid tumors. After a single dose of 60 mg of pamidronate, serum calcium was lowered within 2–3 days, and normocalcemia was maintained for an average of 14 days. The addition of calcitonin lowered serum calcium within 24 h and led to a rapid improvement in hypercalcemic symptoms. Except in patients with hypercalcemia caused by hematological malignancies, the calcium-lowering effect was not enhanced by adding steroids to calcitonin therapy. In patients with moderate to severe symptomatic hypercalcemia, infusions of pamidronate every 2 weeks and calcitonin therapy for the first 2–3 days rapidly reduced serum calcium levels and sustained normocalcemia.