Identification of novel gene amplification events in breast cancer

To identify novel gene amplification events that may contribute to breast cancer progression, we examined copy number variation in 161 primary breast cancer samples using the Affymetrix 250K_Nsp and 250K_Sty microarrays or the Affymetrix SNP5.0 microarray. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from primary breast cancer samples. Copy number variations were determined from probeset signal intensities.