A little more than a dozen years ago two researchers came up with a way of thinking about how tumors grow that changed the way most of the scientific community considered the hundred or more different diseases we call cancer. The varied and complex ways that normal cells become malignant, Douglas Hanahan and Robert Weinberg famously wrote in 2000, could be divided into six main steps—ranging from dividing uncontrollably to avoiding self-destruction. Developing treatments that targeted those essential processes should make cancer therapy much more predictable and effective, they argued.

Things did not turn out quite that way, as George Johnson wrote in the November 2013 issue of Scientific American. If anything, researchers have since learned that the various cellular pathways and molecular signals that prompt an otherwise normal cell to become malignant are even more complicated than they already thought. But Hanahan and Weinberg’s original insight still holds up pretty well as a general way of understanding the underlying process. Douglas Hanahan talks about the six original hallmarks and possibly two new additions in the following video, which was filmed at the 2012 meeting of the European Society for Medical Oncology in Vienna.

Video courtesy of the European Journal of Cancer