PIK3CA and breast cancer: Independently of the subtype of BC and adjuvant treatment received (chemotherapy, hormone therapy, both or none) MFS was significantly better in patients with high COX-2 expression (p=0.007, HR 1.560 [1.130-2.153]) (Figure 2A) and in patients with PIK3CA mutations (p=0.02, HR 1.455 [1.058-2.002]) (Figure 2B).