TNM staging of cancers of the head and neck: striving for uniformity among diversity.

The sixth edition of the tumor-node-metastasis staging system for head and neck cancers incorporates some significant shifts in philosophy. As treatment paradigms shift and data from ongoing clinical and basic research become available, further revisions may be expected in the future. The purpose of this review is to highlight the complexities involved in developing a user-friendly staging system and to report the major changes in the new version. The authors also discuss some areas of current interest that may have the potential to lead to future modifications.