Use of markers in the diagnosis and follow-up of metastases

Abstract

— Tumor markers are antigens which can be associated with certain malignancies. A variety of markers have been proposed for genitourinary tumors. The best known examples are human chorionic gonadotropin (bHCG) and alpha-fetoprotein (AFP) for testicular tumors, prostatic acid phosphatase (PAP) and prostatic specific antigen (PSA) for prostatic cancer. The plasma levels of these substances are influenced by the tumor mass and therefore by the tumor stage. Plasma levels can be markedly high when metastases are present, though a few patients without metastases may elaborate an abnormal amount of markers. The removal of the primary tumor leads to a fall to normal levels: a continuing high level indicates residual primary tumor or the presence of metastases. Measurements of markers are also of value in estimating the effects of medical treatment and in detecting local or distant recurrences.