Doctor's dilemma: incorporating tumor markers into clinical decision-making.

Physicians are often faced with the dilemma of how to incorporate tumor markers into routine clinical decision-making. Tumor markers may influence clinical decisions at various stages of cancer therapy: screening, diagnosis, prognosis, detection of early relapse, and monitoring of therapy. We use the examples of beta-human chorionic gonadotrophin (beta-HCG) and alpha-fetoprotein (AFP) as markers for germ cell tumors (GCT), and prostate-specific antigen (PSA) as a marker for prostate cancer, to illustrate their use and limitations for these purposes. We then focus on monitoring and choice of treatment by presenting three vignettes; these highlight the potential benefits and problems associated with the use of tumor markers for monitoring and detection of early relapse in asymptomatic patients. Copyright 2002, Elsevier Science (USA). All rights reserved.