[The TNM classification of cancer--from the viewpoint of pathology]

The 5th international TNM classification (proposed in 1997) is an anatomical classification of cancers used all over the world. In Japan, various kinds of Japanese classification of cancers have widely been accepted since 1962. Researchers may be confounded at international cancer conferences because of some differences in these classification. We here summarize the history and criteria of the present TNM classification and describe the concept of new N factors additional and in the 5th edition. In the Japanese versions of cancer classification, the concepts of H and P factors should be reconsidered. The importance of the cytologic diagnosis in ascites is discussed and pathological grades of differentiation into the new cancer staging are introduced.