A prognostic factor (PF) index for overall survival in a HER2-negative endocrine-resistant metastatic breast cancer (MBC) population: Analysis from the ATHENA trial.

555 Background: Chemotherapy is the standard of care for patients (pts) with HER2-negative endocrine-resistant MBC. The considerable variability in overall survival (OS) within this population relates essentially to prognostic factors (PF). Increasingly, large studies based on progression-free survival (PFS) as a primary endpoint are now being questioned. An accurate PF index may help in designing innovative trials with appropriate pts selection according to overall survival (OS) prognosis. Methods: The ATHENA trial assessed the safety of first-line bevacizumab combined with non-anthracycline-containing therapy in 2264 pts treated in 37 countries from 2006 to 2009. Pt characteristics, safety, and efficacy have been reported [Breast Cancer Res Treat 2011;130:133-43]. Sixty-one HER2-positive pts were excluded. A multivariate Cox regression model selected PF generating a simple PF index. Of note, skin, lymph node, ipsi-/contra- breast, or other soft tissue involvement was scored as a single organ. Results: A...