Hypercalcemia of Malignancy is a serious condition that occurs when cancer leads to high levels of calcium in the blood. This is a common metabolic complication of cancer and can cause significant symptoms and health risks.
The high calcium levels are primarily caused by two mechanisms:
This is the most common cause. Tumors, particularly squamous cell carcinomas and some others, secrete a parathyroid hormone-related protein (PTHrP). This protein acts like parathyroid hormone, causing bones to release calcium and kidneys to retain it.
This occurs when cancers like breast cancer or multiple myeloma spread (metastasize) to the bones. The tumor cells directly stimulate bone breakdown (resorption), releasing calcium into the bloodstream.
Symptoms of hypercalcemia can be vague and worsen as calcium levels rise. They include:
Diagnosis involves blood tests to confirm high calcium levels and assess kidney function. Measuring PTH and PTHrP levels helps distinguish hypercalcemia of malignancy from primary hyperparathyroidism. Imaging studies may be used to identify bone metastases or the primary tumor.
The primary goals are to lower calcium levels rapidly and treat the underlying cancer. Treatments include:
Given to help the kidneys remove excess calcium from the blood.
Drugs like pamidronate or zoledronic acid are the mainstay of treatment. They inhibit bone resorption and are very effective at lowering calcium levels.
Used for hypercalcemia that does not respond to bisphosphonates. It is a monoclonal antibody that also blocks bone breakdown.
This hormone can lower calcium quickly, but its effect is often short-lived.
Can be helpful for hypercalcemia caused by certain lymphomas or multiple myeloma.
May be necessary in severe cases, especially if kidney failure is present.
The development of hypercalcemia of malignancy is often a sign of advanced cancer. While the condition itself can be managed, the overall prognosis depends on the type and stage of the underlying cancer. Effective treatment of the cancer is the most important factor for long-term control.
This information is for educational purposes. Patients should consult with their healthcare team for diagnosis and treatment.
