[Intra-tissue biological markers in cancers of the breast: current assessment]

Among the great many prognostic factors currently available in breast cancer, three classes of tissue biological parameters appear to be the most reliable in the establishment of a clinical decision flowchart, when they will have been technically and clinically validated: parameters of hormone dependence, tumour aggressiveness and invasion and parameters of proliferation. This article discusses the difficulties encountered in the evaluation of some of these parameters (hormone receptors by various methodological approaches, proteases, enzymes involved in cell proliferation), with emphasis on standardisation of techniques, development of quality controls, clinical validation and objective information of the medical and scientific communities.