Biochemical assessment of tissue prognostic factors in breast cancer

Information on prognosis and probability of response to treatment of breast cancer patients can be derived in part from assessment of prognostic factors in the tumour tissue. Oestrogen and progestin receptors were among the first and still remain important, The generalized use of adjuvant treatments and the diversification of techniques for receptor assays have caused many hospitals to abandon quantitative receptor assay or to refrain from receptor assays completely, New prognostic factors are being proposed more and more frequently, but prior to their generalized acceptance, they should be validated both analytically and clinically to a greater extent than is usually done. Standardization of techniques and establishment of external quality control procedures are part of the technical validation. Among these potentially useful new prognostic factors are the components of the urokinase system such as urokinase type plasminogen activator and its inhibitors, thymidine kinase oestrogen receptor variants with constitutive, i.e. hormone independent, transactivation properties, and prostate specific antigen. Techniques for the assessment of new prognostic factors are at the protein, RNA and DNA level and thus require specialized laboratories with dedicated staff willing to commit to guidelines emerging from international cooperative efforts to provide the best possible laboratory care to the breast cancer patient. To maintain the momentum in the research of such laboratories, it is imperative that they are provided with tissue specimens whenever tumour size allows for it.