Nevertheless, dose-dense chemotherapy for early-stage breast cancer remains an important strategy as it is predicted to maximise the impact of individual cytotoxic agents (Norton et al, 1976; Norton and Simon, 1977; Budman et al, 1998), with encouraging results on long-term outcome (Citron et al, 2003; Moebus et al, 2010), especially in ER-negative and PgR-negative tumours (Berry et al, 2006). This evidence concerns the gene PGR and breast cancer.