News of TNM and its use for classification of gastric cancer.

Tumor classification is associated with two inherent problems: (1) to find a compromise between the simplicity needed for a wide application by the medical community and sufficient differentiation and specification required for the presently high differentiation in treatment options and for detailed analysis of treatment results; and (2) to achieve an agreement between the stability necessary for data collection over long periods and the needed continuous inclusion of new proposals that arise by advances in diagnostic and therapeutic methods and the increasing knowledge of prognostic factors. The aim of this report is to inform on the changes and expansions of the international classification of gastric carcinoma during the last few years, to refer to new developments, to point out the relations between established classifications and molecular biology, and to show the future trend in tumor classification.