BIOCHEMICAL ASSESSMENT OF TISSUE PROGNOSTIC FACTORS IN BREAST-CANCER

Information on prognosis and probability of response to treatment of b reast cancer patients can be derived in part from assessment of progno stic factors in the tumour tissue. Oestrogen and progestin receptors w ere among the first and still remain important, The generalized use of adjuvant treatments and the diversification of techniques for recepto r assays have caused many hospitals to abandon quantitative receptor a ssay or to refrain from receptor assays completely, New prognostic fac tors are being proposed more and more frequently, but prior to their g eneralized acceptance, they should be validated both analytically and clinically to a greater extent than is usually done. Standardization o f techniques and establishment of external quality control procedures are part of the technical validation. Among these potentially useful n ew 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 ind ependent, transactivation properties, and prostate specific antigen. T echniques for the assessment of new prognostic factors are at the prot ein, RNA and DNA level and thus require specialized laboratories with dedicated staff willing to commit to guidelines emerging from internat ional cooperative efforts to provide the best possible laboratory care to the breast cancer patient. To maintain the momentum in the researc h of such laboratories, it is imperative that they are provided with t issue specimens whenever tumour size allows for it.