Parathyroid Hormone-related Peptide (PTH-rP)

Parathyroid hormone-related protein (or PTHrP) is a protein member of the parathyroid hormone family secreted by mesenchymal stem cells. It is occasionally secreted by cancer cells (breast cancer, certain types of lung cancer including squamous-cell lung carcinoma). However, it also has normal functions in bone, tooth, vascular and other tissues.

The PTH-rP assay should not be used to exclude cancer or screen tumor patients for humoral hypercalcemia of malignancy (HHM). The results should always be assessed in conjunction with the patient's medical history, clinical examination, and other findings. If test results are clinically discordant, please contact the laboratory.