Because hormones produced by malignant tumors are often able to be identified and quantified by immunoassays designed to measure normally-produced hormones, elevation of a given hormone is not considered diagnostic of a specific tumor. While these assays are highly sensitive, their lack of specificity limits their utility as a screening tool.
Adrenocorticotropic hormone (ACTH) | Lung (small cell) | ACTH normally produced by the corticotropic cells of the anterior pituitary. May be accompanied with excessive production of cortisol usually associated with Cushing’s syndrome. |
Antidiuretic hormone (ADH) | Lung (small cell), adrenal cortex, pancreatic, intestine | ADH helps to regulate water balance in the blood. Normally ADH is elevated in response to high blood osmolality. Measuring ADH in reference to plasma osmolality increases its sensitivity as a tumor marker. |
Calcitonin | Thyroid, lung, breast, renal, liver | Normally secreted in response to increased serum calcium to inhibit release of calcium from bone. |
Gastrin | Gastrinoma | Fasting plasma gastrin is often greatly increased to several times the upper limit of normal. Considered diagnostic as a tumor marker when elevated 10 times the upper limit of normal in the presence of gastric hypersecretion. |
Glucagon | Glucagonoma (islet-cell pancreatic tumor | Highly metastatic. Sustained elevated glucose levels as glucagon produced is not under control of feedback mechanisms. |
Human chorionic gonadotropin (hCG) | Embryonal, placenta, testicular, choriocarcinoma | Normally elevated during pregnancy. hCG is produced and is highly elevated in trophoblastic or chorionic tumors of embryonic cell origin. |
Insulin | Insulinoma | Sustained increased insulin levels even in fasting state. Insulin-producing tumors are typically non-malignant. |
Parathyroid hormone (PTH) | Liver, renal, breast, lung | Ectopic PTH-producing adenomas are rare, but produce PTH in excess which leads to hypercalcemia. |
Prolactin | Pituitary, renal, lung | Prolactinomas are common, but benign pituitary tumors. Ectopic prolactin-producing carcinomas are very rare. |