St Gallen Expert Consensus meetings update evidence on treatment of early breast cancer every 2 years and interpret its significance for treatment of individual patients. Such interpretation is controversial. Clinical decisions cannot, however, be postponed, and the harms of failing to tailor treatment must be balanced against those of overinterpretation. Since the ninth meeting in January 2005, an extraordinary year of progress has significantly changed the landscape in breast cancer therapy. The panel in January recommended a fundamental change in selection of adjuvant systemic therapy, giving prime attention to endocrine responsiveness. Primarily, three categories were acknowledged: endocrine responsive in which the primary treatment should be endocrine, endocrine non-responsive in which endocrine therapy should not be used, and an intermediate group for which both endocrine and other therapies should be offered. Secondarily, three risk groups were defined: low, intermediate, and high, slightly modifying the previous classification. In June 2005, three trials, supported in December by a fourth, demonstrated the additional contribution of targeted therapy with trastuzumab in appropriately selected patients. Reports from several trials strengthened the evidence supporting the inclusion of taxanes, though controversy persists concerning their use in endocrine-responsive disease. This commentary midway between St Gallen meetings, therefore, emphasizes how new information influences algorithms for selecting adjuvant therapy in a rapidly changing environment.