Bisphosphonate Versus Bisphosphonate and Calcitonin for the Treatment of Moderate to Severe Hypercalcemia of Malignancy

Background Historically, intravenous (IV) bisphosphonates with calcitonin are the treatment of choice for hypercalcemia of malignancy. However, evidence is lacking. Objective The objective of this study was to compare the use of bisphosphonate versus bisphosphonate with calcitonin for moderate to severe hypercalcemia of malignancy. Methods This was a retrospective study evaluating patients who received bisphosphonate and/or calcitonin for treatment of moderate to severe hypercalcemia of malignancy. Patients received usual care plus either (1) bisphosphonate or (2) bisphosphonate with calcitonin. The primary outcome was change in corrected serum calcium concentrations 48 hours after treatment. Secondary outcomes included corrected calcium levels, incidence of normocalcemia and hypocalcemia, time to normocalcemia, hospital length of stay, and cost avoidance. Results The 48-hour decrease in corrected calcium was less in the bisphosphonate group than in the combination group (2.4 [1.6-3.4] vs 3.9 [3.5-5.3];P< 0.001). However, initial calcium levels in the combination group were higher than in the bisphosphonate group, and calcium levels at 24, 48, and 72 hours were similar. Secondary outcomes did not differ. Average cost avoidance with bisphosphonate monotherapy was $11 248 per patient and $291 448 per year. Conclusions and Relevance In the treatment of moderate to severe hypercalcemia of malignancy, IV bisphosphonate in combination with calcitonin resulted in a higher difference in corrected calcium levels at 48 hours compared with bisphosphonate therapy alone. However, corrected calcium levels in the first 72 hours, time to normocalcemia, and clinical outcomes were similar. The addition of calcitonin increases cost without substantial clinical benefit, and providers may consider avoiding calcitonin.