"A new study suggests that the regulation of BCSCs by HER2 may extend to breast cancers that do not display HER2 gene amplification. In these tumors, HER2 is selectively expressed in the CSC population, and this expression is regulated by the tumor microenvironment. In mouse models, trastuzumab blocked growth of these HER2-negative tumors when administered in the adjuvant setting but had no effect on established tumors."
"The 3-yr DFS rates in the HER2-negative group, the HER2-positive group who received trastuzumab treatment, and the HER2-positive group who did not receive trastuzumab treatment were 82.6%, 89.6%, and 67.0%, respectively. The 3-DFS rate for the total study population was statistically significant (P