The molecular landscape of high-risk early breast cancer: comprehensive biomarker analysis of a phase III adjuvant population

A molecular survey of breast tumors reveals features that might help to predict a patient's response to therapy. At present, clinicians largely determine breast cancer treatment strategies according to the level of activity of three signaling proteins: HER2, the estrogen receptor and the progesterone receptor. But this simple classification scheme could conceal other medically informative subpopulations. Researchers led by Mark Lackner and Timothy Wilson at Genentech in California, USA, probed this complexity by performing intensive genetic analysis on biopsies from 861 clinical-trial participants. Their findings revealed features that predicted a better response to a particular chemotherapeutic regimen — for example, the expression of specific sets of genes involved with the immune response correlated with longer disease-free survival in distinct tumor subtypes. Other potentially useful prognostic indicators were also identified, including 18 genes associated with post-treatment recurrence.