Personalized medicine is becoming very important in oncology. New achievements in genomics, molecular biology, toxicology or immunology lead to optimization and personalization of systemic therapy in cancer patients. Breast cancer is an excellent example for which personalized medicine is a real breakthrough in oncology. Targeted molecular therapies have significantly increased cancer patients' benefits and reduced adverse effects of the treatment. A large number of new promising anti-cancer agents and genomic tests are currently being tested in clinical trials. Results of the early clinical trails (Phase I and II) are very promising and provide a real hope for the fast progress of personalized oncology development.