PIK3CA and breast cancer: Indeed, a recent pooled analysis of almost 1000 HER2+ early BC patients from five randomized clinical trials of neoadjuvant treatment with chemotherapy in addition to either Trastuzumab, Lapatinib or the combination of them, reported lower pCR rates in PIK3CA mutant group as compared to the wild-type group, especially in the HR+ subpopulation and in patients receiving the dual HER2 blockade [60].