Hypercalcemia of malignancy treated with cinacalcet

Area of Science:

• Oncology
• Endocrinology
• Medical Case Reports

Background:

• Hypercalcemia of malignancy (HHM) is a frequent complication in advanced cancers, particularly breast cancer, indicating a poor prognosis.
• Breast cancer exhibits the highest prevalence of hypercalcemia among female malignancies, with bone metastases being a common precursor.
• HHM necessitates effective management strategies to improve patient outcomes and quality of life.

Purpose of the Study:

• To report a case of severe HHM in a patient with metastatic breast cancer.
• To evaluate the efficacy of cinacalcet as an add-on therapy for refractory HHM.
• To highlight the management of hypercalcemia in advanced breast cancer.

Main Methods:

• A 69-year-old female patient with metastatic breast cancer and severe HHM was treated with intense hydration, corticosteroids, and antiresorptive agents (calcitonin, bisphosphonates, denosumab).
• Cinacalcet, a calcimimetic agent, was introduced due to persistent hypercalcemia despite initial treatment.
• Treatment response was monitored by serum calcium levels, with particular attention to the effect of cinacalcet initiation and discontinuation.

Main Results:

• Initial treatment with hydration, corticosteroids, and antiresorptives failed to normalize serum calcium levels.
• Addition of cinacalcet led to normalization of calcium levels, which increased upon its discontinuation and normalized again upon re-initiation.
• The patient was discharged on denosumab and a titrated dose of cinacalcet, maintaining normal calcium levels during outpatient follow-up for 11 months.

Conclusions:

• HHM is a significant complication of advanced malignancy, especially breast cancer.
• Intense hydration and bisphosphonates are the primary treatments for HHM.
• Cinacalcet represents a valuable therapeutic option for managing persistent or refractory HHM, as demonstrated in this case study.