Letter

Expression profiling predicts outcome in breast cancer

Laura J van 't Veer^1,2,6 , Hongyue Dai³, Marc J van de Vijver¹, Yudong D He³, Augustinus AM Hart⁴, René Bernards^2,5 and Stephen H Friend³

¹  Division of Diagnostic Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands

²  Center for Biomedical Genetics, The Netherlands Cancer Institute, Amsterdam, The Netherlands

³  Rosetta Inpharmatics, Inc.,* Kirkland, Washington, USA

⁴  Division of Radiotherapy, The Netherlands Cancer Institute, Amsterdam, The Netherlands

⁵  Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands

⁶  A wholly-owned subsidiary of Merck & Co., Inc

author email corresponding author email

Breast Cancer Res 2003, 5:57-58doi:10.1186/bcr562

Published:	4 December 2002

See commentary, http://breast-cancer-research.com/content/5/1/23

First paragraph (this article has no abstract)

Gruvberger et al. postulate, in their commentary [1] published in this issue of Breast Cancer Research, that our "prognostic gene set may not be broadly applicable to other breast tumor cohorts", and they suggest that "it may be important to define prognostic expression profiles separately in estrogen receptor (ER) positive and negative tumors". This is based on two observations derived from our gene expression profiling data in breast cancer [2]: the overlap between reporter genes for prognosis and ER status, and Gruvberger et al.'s inability to confirm the prognosis prediction using a nonoptimal selection of 58 of our 231 prognosis reporter genes.