The TNM system is a widely accepted prognostic system worldwide. Limitations in prognostic accuracy are recognized but have remained for fear the remedy would unnecessarily complicate the system. Understanding of the genetic and molecular mechanisms of cancer will allow the gap between the ideal and the practical prognostic system to be closed and the staging system drastically revised to a modular structure. Novel computational technology, which is reliable and reproducible, is likely to provide the basis for such a modular prognostic system.