Targeted therapies in breast cancer

Targeted therapies have improved cure rates and prolonged survival in metastasised breast cancer. The most important new molecular targets in breast cancer therapy are epidermal growth factor receptor (ErbB) family signalling, DNA repair pathways and angiogenesis. Blocking ErbB2 signalling with anti-ErbB2 antibodies or ErbB2 kinase inhibitors is effective in both the adjuvant and the palliative treatment of ErbB2 positive breast cancer. Poly-ADP-ribose polymerase (PARP) inhibitors lead to synthetic lethality in double strand repair deficient tumours. Anti-VEGF antibodies reduce tumour-induced angiogenesis and prolong progression-free survival in breast cancer. The use of both PARP inhibitors and antiangiogenic therapy is currently hampered by a lack of predictive biomarkers. In contrast, predictive markers are available for ErbB family signalling. This review is intended to give a concise summary of recent developments in the therapy of breast cancer with a focus on new, targeted therapies.