Management of hypercalcemia in a patient with parathyroid carcinoma using the monoclonal antibody Denosumab

• Published in: Experimental and Clinical Endocrinology & Diabetes
• Main Authors: Jumpertz-von Schwartzenberg, R, Elbelt, U, Ventz, M, Strasburger, C, Spranger, J
• Format: Conference Proceeding
• Language: English
• Published: 05.03.2014
• ISSN: 0947-7349; 1439-3646
• DOI: 10.1055/s-0034-1372017

In patients with parathyroid carcinoma treatment options are limited to surgical removement of the primary tumor or metastases. Management of hypercalcemia becomes the principal clinical focus in progressed disease stages, as it is the most common cause of death in these patients. Here, we report about a patient who was first diagnosed in 1992. Local resection of the tumor and complete thyroidectomy lead to left laryngeal nerve palsy. In 2010 bone metastases occurred in the sternum and the rips. Local radiation was followed by in toto resection of the metastases. In 2012 pulmonary metastases were resected. Additionally, a marked increase in parathyroid hormone (PTH) became evident (peak 429 pg/ml). Despite ongoing therapy with bisphosphonates and cinacalcet hydrochloride, calcium levels increased reaching 3.7 mmol/l. After admission to our inpatient unit, under forced diuresis, calcium was reduced to levels between 2.7 and 3.0 mmol/l. Staging imaging uncovered a bone metastasis at vertebra 7 with dorsal instability. After in toto resection of the metastasis, calcium remained above normal and increased even under forced diureses (3.1 mmo/l). PET-CT imaging indicated local recurrence in the right thyroid compartment. Venous catheterization confirmed PTH excess from the right external jugular (1905 pg/ml) and thyroid (1820 pg/ml) vene (compared to 214 pg/ml in the left jugular vene). Further surgery was not an option due to laryngeal nerve palsy on the left side. Here, we decided to try a therapy with denosumab, a humanized monoclonal antibody inhibiting RANK-ligand. After administation of 60 mg, we observed a drop in calcium into the normal range (2.5 mmol/l) within two days. Outpatient visits then showed stable calcium levels at 2.7 mmol/l for 8 months including a second injection after a calcium rise to 3.1 mmol/l after 4 months. We conclude that in patients with parathyroid cancer, denosumab may be a new treatment option for therapy of refractory hypercalcemia.