Predictive factors for response to neoadjuvant therapy in breast cancer.

Within 2 decades, neoadjuvant therapy (NAT) has become a standard treatment option in breast cancer. The advantage of NAT is the ability to monitor the treatment effect. Pathological complete response (pCR) after NAT is a very good predictor for long-term outcome. Clinical factors, such as age and body mass index, as well as recently identified biomarkers can predict the chance of achieving a pCR. Hormone-receptor status, proliferation markers, immune infiltrates and genetic alterations, such as germline BRCA and PIK3CA, can now be measured almost on a routine basis due to the decreased analysis costs.