In the context of cancer, calcium homeostasis can be disrupted in multiple ways. Tumors may induce hypercalcemia, a condition characterized by elevated calcium levels in the blood. This occurs in some cancers due to the secretion of parathyroid hormone-related peptide (PTHrP), which mimics PTH and stimulates bone resorption, releasing calcium into the bloodstream. Additionally, metastatic cancers, particularly those spreading to the bone, can directly cause osteolysis, further contributing to hypercalcemia.
