Tumour Marker
- Substance found in circulation (or immunohistochemical marker)
- Directly related to presence of neoplasm
- Disappears when neoplasm treated, reappears when neoplasm recurs
Not usually stoichiometric - not in direct proportion to tumour bulk
Classification
- Hormones: Eutopical / ectopical
- ACTH
- hGH (pituitary adenoma)
- EPO - renal cell carcinoma
- B-hCG: teratomas, choriocarcinoma
- Enzymes
- Prostatic acic phosphatase (not prostatic specific antigen) - Ca prostate
- Placental alkaline phosphatase - ca bronchus, pancreas, colon
- Oncofetal antigens
- a-fetoprotein (foetal albumin): germ cell tumours, hepatocellular carcinoma
- Carcioembryonic antigen (CEA): colorectal