[Value of tumor biological prognostic factors in adjuvant therapy of node-negative breast cancer].

In an extensive meta-analysis it was shown that adjuvant therapy improves the course of the disease in breast cancer. This risk reduction was observed independent of the stage of disease in the same percentage in node-negative and node-positive patients. As a consequence, recommendations were given to offer all patients some kind of adjuvant therapy regardless of lymph node status. In node-negative disease, however, prognosis is assumed to be good in general, as about 70% are cured by locoregional surgery alone. Therefore it was alternatively suggested to select high-risk node-negative patients for adjuvant chemotherapy by a combination of different prognostic factors. Both, established and new prognostic factors should meet strict statistical and methodological requirements before clinical application to therapeutic decisions is justified. The malignant potential of solid tumors consists in their capacity for fast proliferation on the one hand and for invasion and metastasis on the other. Estimation of proliferation rate in breast cancer is now possible by determination of S-phase fraction, thymidine labelling index (TLI), or Ki-67 (MIB-1) antigen. Also steroid receptors (inverse correlation) and EGF-R show a high correlation with proliferation parameters; they can therefore be regarded as indirect indicators for proliferation. Unfortunately up to now none of these factors is of satisfactory clinical value for node negative breast cancer. Factors capable to quantify invasive and metastatic capacity of malignant cells should be even more suitable for estimation of prognosis, as mortality in the disease is predominantly based on occurrence of distant metastasis.(ABSTRACT TRUNCATED AT 250 WORDS)