[The analgesic effect of calcitonin on breast cancer patients with bone metastases].

Lately it has been reported that calcitonin is effective for the treatment of hypercalcemia and for the relief of pain caused by osteolytic bone metastasis. Thus we have studied the analgesic effect of synthetic eel calcitonin (ECT) on 8 breast cancer patients with bone metastases. ECT was administered in the dose of 20 or 40 I.U. twice a day intramuscularly for 7 days without other antineoplastic treatment, and the laboratory data of its analgesic effect and change has been examined. An analgesic effect was obtained on all 8 patients who had received ECT. However, an improvement of radiological findings of metastatic osteolysis and a decrease in urine hydroxyproline were not found after short term (7 days) treatment with calcitonin. These results suggest that the effect of ECT on the relief from pain due to bone metastasis is not caused by an improvement of the osteolytic metastatic lesions.