An overview of drug development for metastatic breast cancer.

The prevalence of breast cancer is increasing as more women are living with the disease. Outcomes have improved as a result of progress in all major aspects of multidisciplinary care. These include surgery, radiotherapy, hormonal therapy, chemotherapy and newer targeted drugs. Two aspects merit particular attention here. First, there is an understanding now that cancer is a heterogenous disease and a 'one-size-fits-all' approach is becoming redundant, albeit slowly. Second, basic science and an appreciation of cellular molecular targets in those different types of breast cancer is being translated into the clinic and has led to the development of exciting new drugs for both triple negative and HER2-positive relapsed disease. An improved understanding of endocrine resistance remains an unmet need in drug development and here, it appears worthwhile to adopt less conventional approaches. Better trial design with a focus on biomarkers should lower barriers to regulatory approval as well as increase cost effectiveness.