Continuing controversies in staging NSCLC: an analysis of the revised 1997 staging system.

The 1997 revision of the lung cancer staging system has added very little to disease staging, and many changes have been totally unnecessary. Before the next revision of the staging system, anticipated in the year 2007, a worldwide effort to collect accurate data bases and analyze a variety of T, N, and M prognostic factors as well as the newer biologic factors is required to define more accurately the clinical and pathologic stages of lung cancer according to prognosis. This approach would allow a more rational consideration of changes in TNM staging. As well, a single, universally accepted lymph node map is needed desperately to unify staging concepts worldwide.