Personalized medicine in cancer: where are we today?

What is personalized medicine? In an ideal world, our vision for personalized medicine involves measurement of some key tumor characteristics which inform the optimum therapy regimen tailored for each given patient to successfully treat their cancer and prevent relapse. In reality, things are not so simple. Cancer is enormously complex and heterogeneous and the current gaps in our knowledge preclude this vision from becoming a reality in the very near future. On the upside, ground-breaking advancements in technology and approaches in recent years have enabled tremendous strides in this direction, but we have a long way to go if this vision is to be fully realized.