PRECLINICAL STUDY Validation of 70-gene prognosis signature in node-negative breast cancer

improve the selection of lymph node-negative breast cancer patients for adjuvant systemic therapy. Optimal validation of prognostic classifiers is of great importance and we therefore wished to evaluate the prognostic value of the 70-gene prognosis signature in a series of relatively recently diagnosed lymph node negative breast cancer patients. Methods We evaluated the 70-gene prognosis signature in an independent representative series of patients with invasive breast cancer (N = 123; \55 years; pT1-2N0; diagnosed between 1996 and 1999; median follow-up 5.8 years) by classifying these patients as hav-ing a good or poor prognosis signature. In addition, we updated the follow-up of the node-negative patients of the previously published validation-series (Van de Vijver J. L. Peterse—deceased. Electronic supplementary material The online version of this article (doi:10.1007/s10549-008-0191-2) contains supplementary material, which is available to authorized users