The 12th St Gallen International Breast Cancer Conference (2011) Expert Panel 
adopted a new approach to the classification of patients for therapeutic 
purposes based on the recognition of intrinsic biological subtypes within the 
breast cancer spectrum. For practical purposes, these subtypes may be 
approximated using clinicopathological rather than gene expression array 
criteria. In general, systemic therapy recommendations follow the subtype 
classification. Thus, 'Luminal A' disease generally requires only endocrine 
therapy, which also forms part of the treatment of the 'Luminal B' subtype. 
Chemotherapy is considered indicated for most patients with 'Luminal B', 'Human 
Epidermal growth factor Receptor 2 (HER2) positive', and 'Triple negative 
(ductal)' disease, with the addition of trastuzumab in 'HER2 positive' disease. 
Progress was also noted in defining better tolerated local therapies in selected 
cases without loss of efficacy, such as accelerated radiation therapy and the 
omission of axillary dissection under defined circumstances. Broad treatment 
recommendations are presented, recognizing that detailed treatment decisions 
need to consider disease extent, host factors, patient preferences, and social 
and economic constraints.