Has the new TNM classification for colorectal cancer improved care?

In 2009, the Union for International Cancer Control issued the seventh edition of the well-used T (tumor), N (node), and M (metastasis) classification guidelines. There has been a continual refinement of the staging for colorectal cancer since this system for assessing tumor stage was initially adopted and it has been used to guide treatment decisions for over 50 years. However, the outcome after therapy for patients with colorectal cancer is very variable, even when patients are assigned to the same TNM category. This article assesses the changes that have been made since the sixth edition and discusses whether they are, in fact, informative improvements for a practicing clinician.