Treatment of cancer-associated hypercalcemia with cisplatin.

Cisplatin (cis-platinum) has been shown to lower cancer-associated humoral hypercalcemia in an animal model and to inhibit bone resorption in vitro. This prospective study was designed to evaluate the efficacy of cisplatin in treating cancer-associated hypercalcemia in humans. Thirteen patients with severe hypercalcemia refractory to rehydration were treated with a 24-hour infusion of cisplatin, 100 mg/m2. Serial measurements of serum calcium and tumor size were made following cisplatin treatment and compared with pretreatment values. Nine patients (69%) achieved normocalcemia after treatment with cisplatin; and mean duration of benefit was 38 days in these patients. No reduction in tumor size was seen. All patients died of progressive cancer. We conclude that cisplatin can control malignant hypercalcemia for relatively long periods, and that its mechanism of action is not due to a reduction in tumor size.