Diagnosis of hypercalcaemia associated with cancer

Hypercalcaemia, defined as a corrected serum calcium concentration above 2.60 mmol/L, is associated with many types of cancer, particularly squamous cell lung cancer, breast cancer and multiple myeloma. Serum calcium concentration is corrected for plasma albumin concentration, which is frequently low in patients with cancer. If the albumin concentration is significantly abnormal, consider measuring serum ionised calcium directly.

Note: It is vital to recognise hypercalcaemia associated with cancer.

It is vital to recognise hypercalcaemia associated with cancer; many of the symptoms and signs are nonspecific, making identification difficult. Features include confusion, delirium, nausea, vomiting, worsening pain, constipation, thirst and polyuria. Hypercalcaemia can cause acute kidney injury, exacerbate chronic kidney disease, and precipitate electrolyte and cardiac rhythm abnormalities.

Causes of hypercalcaemia that are not associated with cancer can also contribute to an elevated calcium concentration; see the Bone and Metabolism guidelines for further information.