Beschreibung:
<jats:title>Abstract</jats:title><jats:sec><jats:label /><jats:p>Breast cancer (BC) is the second most common cause of cancer‐related deaths in women worldwide. The availability of reliable biomarkers of response/resistance to cancer treatments would benefit patients and clinicians allowing for a better selection of BC patients most likely to respond to a specific treatment. Phosphatidylinositol 3‐kinase (PI3K) enzymes are involved in numerous cellular‐ functions and processes. The gene encoding for PI3K catalytic subunit p110α is mutated in 20‐40% of BC. We performed a meta‐analysis of the current literature on randomized clinical trials, investigating the role of <jats:italic>PIK3CA</jats:italic> mutational status as prognostic factor, and predictor of response to anti‐cancer treatments. Overall 1929 cases were included. The pooled analysis confirmed that the presence of a <jats:italic>PIK3CA</jats:italic> mutation represents an independent negative prognostic factor (HR = 1.67, 95%CI: 1.15‐2.43; <jats:italic>P</jats:italic> = 0.007) in BC, as previously reported. As PI3K signaling is also a result of other pathways’ hyperactivation, further investigation of potential biomarkers able to predict likelihood of response to anti‐PI3K/mTOR, anti‐HER2, and other TKRs is warranted in future randomized clinical trials.</jats:p></jats:sec>