A review of the role of established tumour markers.

Increasing numbers of commercial assays for the established tumour markers are available which are capable of excellent analytical performance. Whilst all these assays are useful as research tools, their clinical value is more limited and should be appreciated before any decision is taken to offer a tumour marker assay service. 1. Calcitonin (medullary carcinoma of thyroid), alphafetoprotein (hepatoma) and human chorionic gonadotrophin (choriocarcinoma) are the only tumour markers that can be used for screening for malignancy in high risk populations. 2. Hormones, paraproteins, alphafetoprotein, human chorionic gonadotrophin and prostate specific antigen are valuable in establishing the diagnosis of certain tumour types. 3. Alphafetoprotein and human chorionic gonadotrophin concentrations at the time of diagnosis are of value in predicting prognosis in specific tumour types. 4. Although their sensitivity for a particular tumour type may be poor, most tumour markers can be used for monitoring the therapy and follow-up of selected marker positive patients. Optimal clinical results of the management of patients with malignancy are usually obtained by specialist centres, and laboratory tumour marker services should be established so that they are appropriate to local oncology specialities.