The prognostic value of PI3K mutational status in breast cancer: A meta‐analysis

Abstract 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 PIK3CA 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 PIK3CA mutation represents an independent negative prognostic factor (HR = 1.67, 95%CI: 1.15‐2.43; P = 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.